MULTI-YEAR EFFECTS OF GRANULAR AND FOLIAR NITROGEN FERTILIZERS ON
PENN ‘A-4’ CREEPING BENTGRASS (AGROSTIS PALUSTRIS HUDS.) GROWN ON
THREE ROOTZONES
By
Miyuan Xiao

A THESIS
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
MASTERS OF SCIENCE
Crop and Soil Sciences
2012

ABSTRACT
MULTI-YEAR EFFECTS OF GRANULAR AND FOLIAR NITROGEN FERTILIZERS ON
PENN ‘A-4’ CREEPING BENTGRASS (AGROSTIS PALUSTRIS HUDS.) GROWN ON
THREE ROOTZONES
By
Miyuan Xiao
Research on the multi-year effects of foliar and granular nitrogen fertilizers alone or in
combination on turfgrass tissue and soil nutrient concentrations is limited. The research objective
was to determine the effect of different foliar and granular nitrogen fertilizers on Penn ‘A-4’
creeping bentgrass (Agrostis palustris Huds.) grown on three putting green rootzones. The
fertilizer treatments were urea, methylene urea, natural organic, foliar alone, foliar + granular,
and an untreated control. The three rootzones were a United States Golf Association
specification rootzone (80:20, v:v), sand/peat/soil rootzone (80-10-10, v:v:v) and a sandy clay
loam. The urea, methylene urea, and natural organic fertilizer treatments were applied at 24.4 kg
-1

-1

-1

-1

-1

-1

N ha month . The foliar treatment was applied at two rates, 12.2 kg N ha month and 24.4 kg
N ha month . Soil and tissue samples were collected in October 2009, June 2010, October
2010, June 2011, and October 2011. Turfgrass color, quality and chlorophyll ratings were
measured weekly for 2009 - 2011. Ball roll distance was measured in July and August in 2010
and 2011 using a Pelzmeter. Dollar spot (Sclerotinia homeocarpa) and worm casting mounds
were counted throughout the season when present. Results indicate that higher soil N, P, and K
values did not result in higher tissue N, P, and K values among rootzones. Granular fertilizers
had better color and quality in the late fall and faster green up in the spring. Foliar applications
result in better turfgrass color and quality under summer stress. The natural organic treatment
had the shortest ball roll distance, and the largest percentage of annual bluegrass invasion.

To Kuo-Hsien and Emma, for your love and support.

iii

ACKNOWLEDGMENTS

I would like to express my gratitude to my advisor, Dr. Kevin Frank, for his support,
patience, and friendship throughout my graduate life. I appreciate his guidance through many of
my anxieties for my research and future steps. I feel very fortunate to have him as my advisor. I
would like to thank Dr. Thom Nikolai, for his encouragement and humor, and for introducing me
to the world of research when I was an intern student. I would also like to thank Dr. Joe Vargas
for his encouragement and insight on my research, and for giving me the opportunity of being his
teaching assistant. I would like to acknowledge Jeff Bryan and Aaron Hathaway, for their help
and support in my research and their valuable friendship in my life.	
  I would also like to thank
Diana Frank and Kim Bryan, who treat me as one of their family members. As an international
student, I could not have enjoyed my stay here without their love and support.
I specially thank my mother, Lixia Xiao for coming all the way from China to take care
of my baby. This thesis could not have been completed without her support and love. Last but
not least, I thank my husband, Kuo-Hsien and my daughter, Emma for making my life complete.
They are the best gifts in my life.

iv

TABLE OF CONTENTS

LIST OF TABLES ......................................................................................................................... vi
Introduction ......................................................................................................................................1
Literature Review.............................................................................................................................3
Turfgrass Fertilizer.......................................................................................................................3
Soil and Tissue Nutrient Analysis................................................................................................9
Turfgrass Rootzone and Soil Property .......................................................................................13
Playability ..................................................................................................................................15
Dollar Spot Suppression ............................................................................................................16
Annual Bluegrass Invasion ........................................................................................................17
Materials and Methods ...................................................................................................................18
Results and Discussion ..................................................................................................................26
Soil Nutrient Analysis ................................................................................................................26
Tissue Nutrient Analysis ............................................................................................................36
Color, Quality, and Chlorophyll ................................................................................................46
Clipping Dry Weight..................................................................................................................93
Ball Roll Distance ......................................................................................................................96
Water Infiltration Rate ...............................................................................................................96
Dollar Spot Occurence .............................................................................................................106
Worm Casting Occurence ........................................................................................................110
Annual Bluegrass Invasion ......................................................................................................118
Conclusions ..................................................................................................................................121
Appendix ......................................................................................................................................124
Literature Cited ............................................................................................................................147

v

LIST OF TABLES

Table 1.

Treatment design and research plot map. ....................................................................19

Table 2.

Fertilizer treatments. ....................................................................................................21

Table 3.

Phosphorous (P2O5) recommendation for the Urea+phophorous treatment from soil
test results of October 2009 and 2010..........................................................................22

Table 4.

Potassium (K2O) recommendation for the Urea+K treatment from soil test results of
October 2009 and 2010. ...............................................................................................23

Table 5.

Analysis of variance for soil nitrate nitrogen (NO3-N), total nitrogen (Total N),
phosphorus (P), and potassium (K) of Penn ‘A-4’ creeping bentgrass 2009-2011. ...27

Table 6.

Lsmean soil nitrate nitrogen (NO3-N) for the rootzone x sampling date interaction. 28

Table 7.

Lsmean soil nitrate nitrogen (NO3-N) for the fertilizer treatment effect of Penn ‘A-4’
creeping bentgrass. .......................................................................................................29

Table 8.

Lsmean soil total nitrogen (N) for the rootzone effect of Penn ‘A-4’ creeping
bentgrass. .....................................................................................................................31

Table 9.

Lsmean bentgrass soil phosphorus (P) for the rootzone x sampling date interaction..32

Table 10. Lsmean soil potassium (K) for the rootzone x sampling date interaction. ..................34
Table 11. Lsmean soil potassium (K) for the rootzone x fertilizer treatment interaction. ..........35
Table 12. Analysis of variance for tissue nitrogen (N), phosphorus (P), and potassium (K) of
Penn ‘A-4’ creeping bentgrass in 2009, 2010, and 2011. ...........................................37
Table 13. Lsmean creeping bentgrass tissue total nitrogen (N) for the fertilizer treatment x
sampling date interaction. ...........................................................................................38
Table 14. Lsmean bentgrass tissue total nitrogen (N) for the rootzone x sampling date
interaction. ..................................................................................................................39
Table 15. Lsmean tissue phosphorous (P) for the fertilizer treatment x sampling date interaction.
......................................................................................................................................41
Table 16. Lsmean tissue phophorous (P) for the rootzone x sampling date interaction. ............42

vi

Table 17. Lsmean tissue potassium (K) for the fertilizer treatment x sampling date interaction.
......................................................................................................................................44
Table 18. Lsmean creeping bentgrass tissue potassium (K) for the rootzone x sampling date
interaction. ..................................................................................................................45
Table 19. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’
creeping bentgrass. ......................................................................................................48
Table 20. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’
creeping bentgrass by year. .........................................................................................49
Table 21. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from June to
October in 2009............................................................................................................50
Table 22. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction
at four weeks after fertilizer application for each month from June to October in 2009.
......................................................................................................................................51
Table 23. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from June to
October in 2009............................................................................................................52
Table 24. Lsmean creeping bentgrass quality rating for the rootzone x sampling date interaction
at four weeks after fertilizer application for each month from June to October in 2009.
......................................................................................................................................53
Table 25. Lsmean chlorophyll rating for the fertilizer treatment effect of Penn ‘A-4’ creeping
bentgrass in 2009. ........................................................................................................54
Table 26. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from April to
October in 2010. ..........................................................................................................56
Table 27. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction
at four weeks after fertilizer application for each month from April to October in 2010.
......................................................................................................................................57
Table 28. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from April to
October in 2010............................................................................................................58
Table 29. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in at four
weeks after fertilizer application for each month from April to October in 2010. ......60

vii

Table 30. Lsmean creeping bentgrass chlorophyll rating for the fertilizer treatment x sampling
date interaction at four weeks after fertilizer application for each month from June to
October in 2010............................................................................................................61
Table 31. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from April to
October in 2011............................................................................................................63
Table 32. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction
at four weeks after fertilizer application for each month from April to October in 2011.
......................................................................................................................................64
Table 33. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from April to
October in 2011............................................................................................................65
Table 34. Lsmean creeping bentgrass quality rating for the rootozone x sampling date
interaction at four weeks after fertilizer application for each month from April to
October in 2011............................................................................................................66
Table 35. Lsmean creeping bentgrass chlorophyll rating for the fertilizer treatment x sampling
date interaction at four weeks after fertilizer application for each month from June to
October in 2011............................................................................................................67
Table 36. Lsmean creeping bentgrass chlorophyll rating for the rootzone x sampling date
interaction at four weeks after fertilizer application for each month from June to
October in 2011............................................................................................................68
Table 37. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’
creeping bentgrass in April, June, August, and October in 2009, 2010, and 2011. .....70
Table 38. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction
in April 2010 and 2011. ...............................................................................................71
Table 39. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date
interaction in April 2010 and 2011. .............................................................................72
Table 40. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in April
2010 and 2011. .............................................................................................................73
Table 41. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction
in June 2009, 2010, and 2011. .....................................................................................75
Table 42. Lsmean bentgrass color rating for the rootzone x sampling date interaction in June
2009, 2010, and 2011. ..................................................................................................76

viii

Table 43. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date
interaction in June 2009, 2010, and 2011. ...................................................................77
Table 44. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in June
2009, 2010, and 2011. ..................................................................................................78
Table 45. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in June 2009, 2010, and 2011. ...................................................................80
Table 46. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
June 2009, 2010, and 2011. .........................................................................................81
Table 47. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction
in August 2009, 2010, and 2011. .................................................................................83
Table 48. Lsmean bentgrass color rating for the rootzone effect in August 2009, 2010, and 2011.
......................................................................................................................................84
Table 49. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date
interaction in August 2009, 2010, and 2011. ...............................................................85
Table 50. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in August 2009, 2010, and 2011. ...............................................................86
Table 51. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
August 2009, 2010, and 2011. .....................................................................................87
Table 52. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction
in October 2009, 2010, and 2011. ................................................................................89
Table 53. Lsmean bentgrass color rating for the rootzone x sampling date interaction in October
2009, 2010, and 2011. ..................................................................................................90
Table 54. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date
interaction in October 2009, 2010, and 2011.. .............................................................91
Table 55. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in
October 2009, 2010, and 2011. ....................................................................................92
Table 56. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in October 2009, 2010, and 2011. ..............................................................94
Table 57. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
October 2009, 2010, and 2011. ....................................................................................95

ix

Table 58. Analysis of variance results for bentgrass clipping dry weight for 2009, 2010, and
2011..............................................................................................................................97
Table 59. Lsmean bentgrass clipping dry weight for the fertilizer treatment x sampling date
interaction. ...................................................................................................................98
Table 60. Lsmean bentgrass clipping dry weight for the rootzone x sampling date interaction. 99
Table 61. Lsmean bentgrass clipping dry weight for the rootzone x fertilizer treatment
interaction. .................................................................................................................100
Table 62. Analysis of variance results for bentgrass ball roll distance for 2010 and 2011. ......101
Table 63. Lsmean bentgrass ball roll distance for the fertilizer treatment effect for 2010 and
2011............................................................................................................................102
Table 64. Lsmean bentgrass ball roll distance for the rootzone effect for 2010 and 2011.. ......103
Table 65. Analysis of variance results for water infiltration rate for October 2010 and 2011. .104
Table 66. Lsmean bentgrass water infiltration rate for the rootzone effect for October 2010 and
2011............................................................................................................................105
Table 67. Analysis of variance results for dollar spot occurrence for 2010 and 2011. .............107
Table 68. Lsmean bentgrass dollar spot occurance for the fertilizer treatment effect.. .............108
Table 69. Lsmean bentgrass dollar spot occurance for the rootzone effect.. .............................109
Table 70. Analysis of variance results for worm casting occurance for 2010 and 2011... ........111
Table 71. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on July 30, 2010. ......................................................................................112
Table 72. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on August 13, 2010. .................................................................................113
Table 73. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on September 14, 2010. ...........................................................................114
Table 74. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on July 29, 2011. ......................................................................................115
Table 75. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on August 6, 2011. ...................................................................................116

x

Table 76. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on September 2 2011.. .............................................................................117
Table 77. Analysis of variance results for annual bluegrass invasion on May 20, 2011.. .........119
Table 78. Lsmean annual bluegrass invasion for the fertilizer treatment effect on May 20, 2011.
.....................................................................................................................................120
Table A1. Analysis of variance for soil calcium (Ca) and magnesium (Mg) of Penn ‘A-4’
creeping bentgrass in 2009, 2010, and 2011. .............................................................125
Table A2. Lsmean bentgrass soil calcium (Ca) for the rootzone x sampling date interaction....
....................................................................................................................................126
Table A3. Lsmean bentgrass soil magnesium (Mg) for the rootzone x sampling date interaction.
.....................................................................................................................................127
Table A4. Analysis of variance for tissue nutrients of Penn ‘A-4’ creeping bentgrass in 2009,
2010, and 2011. ..........................................................................................................128
Table A5. Lsmean creeping bentgrass tissue calcium (Ca) for the rootzone x fertilizer treatment
interaction. .................................................................................................................129
Table A6. Lsmean bentgrass tissue calcium (Ca) for the rootzone x sampling date interaction.
....................................................................................................................................130
Table A7. Lsmean creeping bentgrass tissue magnesium (Mg) for the rootzone x fertilizer
treatment interaction. .................................................................................................131
Table A8. Lsmean bentgrass tissue magnesium (Mg) for the rootzone x sampling date
interaction.. ................................................................................................................132
Table A9. Lsmean creeping bentgrass tissue sulfur (S) for the rootzone x fertilizer treatment
interaction. .................................................................................................................133
Table A10. Lsmean bentgrass tissue sulfur (S) for the rootzone x sampling date interaction ....134
Table A11. Lsmean creeping bentgrass tissue iron (Fe) for the rootzone x fertilizer treatment
interaction. ................................................................................................................135
Table A12. Lsmean bentgrass tissue iron (Fe) for the rootzone x sampling date interaction......136
Table A13. Lsmean creeping bentgrass tissue manganese (Mn) for the rootzone x fertilizer
treatment interaction. ................................................................................................137

xi

Table A14. Lsmean bentgrass tissue magnesium (Mn) for the rootzone x sampling date
interaction. ................................................................................................................138
Table A15. Lsmean creeping bentgrass tissue zinc (Zn) for the rootzone x fertilizer treatment
interaction. ................................................................................................................139
Table A16. Lsmean bentgrass tissue zinc (Zn) for the rootzone x sampling date interaction. ....140
Table A17. Lsmean creeping bentgrass tissue copper (Cu) for the rootzone x fertilizer treatment
interaction. ................................................................................................................141
Table A18. Lsmean bentgrass tissue copper (Cu) for the rootzone x sampling date interaction.
...................................................................................................................................142
Table A19. Lsmean creeping bentgrass tissue boron (B) for the rootzone x fertilizer treatment
interaction. ................................................................................................................143
Table A20. Lsmean bentgrass tissue boron (B) for the rootzone x sampling date interaction. ...144
Table A21. Lsmean creeping bentgrass tissue aluminum (Al) for the rootzone x fertilizer
treatment interaction. ................................................................................................145
Table A22. Lsmean bentgrass tissue aluminum (Al) for the rootzone x sampling date interaction.
...................................................................................................................................146

xii

INTRODUCTION

Different types and forms of fertilizers have been widely used in the golf industry.
Granular fertilizers such as urea are most commonly used (Carrow et al., 2001). There is an
increasing use of foliar fertilizers because it results in faster plant response, uniform coverage
(Marschner, 1995), reduction of nutrient losses through runoff and leaching, and better turf
growth when under summer stress (Liu et al., 2008). However, the time of year affects foliar
nitrogen absorption efficiency, with the cooler temperatures showing lower N uptake (Stiegler et
al., 2011). Slow release fertilizers have been researched to overcome the drawbacks of urea.
However, it is a challenging task to match the N release rate with plant N demand, because the N
release from slow-release fertilizers are strongly dependent on environmental conditions, such as
soil temperature, moisture level and microbial activities (Wu et al., 2010).
Totten et al. (2008) compared foliar and/or granular N fertilization on 'L-93' creeping
bentgrass. Their treatments included 100% granular urea fertilizer, 50% granular urea + 50%
−1

liquid urea fertilizer, and 100% liquid urea fertilizer at two annual N rates: 127 and 190 kg ha .
They concluded that combining both liquid and granular methods resulted in better turfgrass
quality, more clipping yield, and root biomass compared to relying on one method exclusively.
Soil nutrient analysis is the primary means of assessing available nutrients for turfgrass
and is primarily used in developing guidelines for fertilization programs (Carrow et al., 2001).
However, tissue test provides the nutrient concentration in the plant at the sampling day. Petrovic
et al. (2005) researched the relationship between extractable soil and tissue P and K
concentrations with turfgrass quality and shoot growth. They concluded that N, P, and K tissue

1

levels were not well correlated with turfgrass quality, and N application amount may affect P and
K recommendations.
There is limiting research on the multi-year effects of foliar and granular nitrogen
fertilizers on turfgrass tissue and soil nutrient concentrations. Objectives of this research were to
evaluate soil and tissue nutrient status in turfgrass, and to determine the effects of different forms
of fertilizers on Penn ‘A-4’ creeping bentgrass (Agrostis palustris Huds.) grown on three putting
green rootzones.

2

LITERATURE REVIEW
Turfgrass Fertilizers
Fertilization is one of the important turfgrass management practices to improve soil
nitrogen (Walker et al., 2007), and therefore to maintain turfgrass playable, aesthetic, and
functioning. Turfgrass requires a more frequent fertilization program than crops and other plants
because of regular mowing. Selection of turfgrass fertilizers is based on the quickness of
response desired, application rates, and other economic and environmental factors (Landschoot
and Waddington, 1987). Most turfgrass fertilizers are solid, granular products (Carrow et al.,
2001). Recently, liquid and foliar products have been applied and studied frequently.

Granular, liquid, and foliar fertilizers
Fertilizers can be absorbed by turfgrass through roots and turf tissue. Granular fertilizers
such as urea, methylene urea, and natural organic are targeted at root absorption. Liquid
fertilizers can be clear liquids or in suspension or slurry form (Carrow et al., 2001). About 30 60% of liquid nitrogen fertilizer applied is absorbed by turfgrass tissue (Rieke, 1982; Bowman
and Paul, 1989, 1990, 1992; Liu, 2005; Totten, 2006b). The rest may be left in the turf-soil
system, which still has a better chance of being taken up by roots than granular fertilizers (Liu et
al., 2008). Foliar fertilizers are a dilute solution of plant nutrients that are sprayed onto plant
foliage with the objective of being absorbed through the plant tissue (Beard, 2005). Many
research use the term liquid fertilization for foliar fertilization, especially when describing liquid
urea, because a certain amount of liquid urea goes into the foliage as well as the roots (Bowman
and Paul, 1990, 1992; Marschner, 1995; Hull and Liu, 2005).

3

Major advantages of foliar fertilization compared to granular fertilizers include faster
plant response and rapidly correcting nutrient deficiencies (Marschner, 1995). Foliar fertilization
provides more uniform coverage than granular fertilization, and does not have the issues of
possibly collecting granules when mowing (Mancino et al., 2001). The proper rate of foliar
application will reduce nutrient losses through runoff and leaching (Liu et al., 2008). In summer
time for cool season turfgrasses, foliar fertilization is a good option to overcome root stress and
unfavorable soil conditions. However, foliar fertilization with low nitrogen rates requires
frequent applications, which increase labor costs, and could potentially increase unwanted weeds
(Stiegler et al., 2003). Also, high volatilization rates (Wesly, 1985) and foliar burn (Johnson and
Christians, 1984) are concerns for turfgrass managers.
Stiegler et al. (2011) evaluated the efficiency of foliar fertilization of liquid urea with the
−2

rate of 0.5 and 1.25 g N m

−1

month . Their results showed that the time of year affects foliar

nitrogen (N) absorption efficiency, with the cooler season showing lower N uptake. The authors
also found that the higher N rate resulted in the significantly lower N uptake efficiency. Pease et
al. (2011) compared the effects of liquid forms of ammonium sulfate, urea, ammonium nitrate,
and calcium nitrate at the N rate of 49, 146, 244 kg ha

−1

yr

−1

on velvet bentgrass (Agrostis

canina L.) grown on two putting green rootzones (sand/peat 80:20, v:v and Troxel silt loam).
Their results showed that higher N rates treatments increased clipping yield, shoot density, and
−1

chlorophyll index, and decreased ball roll distances. For the silt loam rootzone, 146 kg N ha
yr

−1

is usually regarded as the rate for maintaining an acceptable turf quality. Higher N rate

better alleviated velvet bentgrass mid-summer stress than lower N rate. Totten et al. (2008)
compared liquid and/or granular N fertilization on 'L-93' creeping bentgrass. Their treatments

4

included 100% granular urea fertilizer, 50% granular urea + 50% liquid urea fertilizer, and 100%
−1

liquid urea fertilizer at two annual N rates: 127 and 190 kg ha . They concluded that combining
both liquid and granular methods resulted in better turfgrass quality, more clipping yield, and
root biomass compared to relying on one method exclusively.

Slow-release N vs. quick-release N fertilizers
There are two forms of N fertilizers according to the water soluble and N release rate:
quick-release N and slow-release N. Application of quick-release N (nitrate and ammonia based
fertilizers) often leads to rapid greening, improved turfgrass quality, and higher N uptake by
turfgrass (Landschoot and Waddington, 1987). Urea is the most widely used quick-release N
fertilizer that can be applied either as liquid or as granular. However, liquid urea application
might injure foliage (Beard, 1973) and might cause nitrate leaching and ground water pollution
(Saha et al., 2007).
Alternative N sources for turfgrass fertilizers have been studied to overcome the
drawbacks of urea. Research has focused on slow-release N fertilizers such as polymer-coated
sulfur-coated urea (PCSCU), ureaformaldehyde (UF), isobutylidene diurea (IBDU), and natural
organics (Landschoot and Waddington, 1987; Quiroga-Garza et al., 2001). Guillard and Kopp
(2004) recommended that a larger fraction of slow-release N than quick-release N should be
formulated in turfgrass fertilizers, as a way to reduce NO3-N leaching in the southern New
England environment. Petrovic (2004) indicated that using slow-release N sources such as
PCSCU and natural organics is one of the solutions to reduce nitrate leaching from turfgrass
rootzones. Wu et al. (2010) compared different N sources and rates on Tall Fescue [Schedonorus
phoenix (Scop.) Holub], and also concluded that slow-release N had less nitrate leaching than

5

fast-release N among all the N sources they applied. However, it is a challenging task to match
the N release rate with plant N demand, because the N release from slow-release fertilizers are
strongly dependent on environmental conditions, such as soil temperature, moisture level and
microbial activities (Wu et al., 2010).
Turfgrass species have different responses to N source. Steinke et al. (2003) concluded
that liquid urea absorbed by turfgrass tissue significantly improved color and quality of creeping
bentgrass (Agrostis stolonifera L.), while Kentucky bluegrass (Poa pratensis L.) responded
better to granular urea taken up by roots. Moreover, Carrow (1997) observed a great diversity in
N-release patterns for slow-release fertilizers across N carrier classes and within a class.
Variation within an N carrier class indicated each fertilizer carrier requires a further study for an
effective N uptake.

Turfgrass Phosphorous fertilization
Phosphorous (P) plays an important role in forming high-energy bond in adenosine
diphosphate (ADP) and adenosine triphosphate (ATP) for storing and transferring energy in the
plant. P is also an important structural constituent in nucleic acids, lipids, phosphoproteins, and a
number of other biochemicals (Hopkins, 1995). A starter fertilizer high in P content for initial
turfgrass establishment is often used to support root and tiller growth (Frank et al., 2002).
Phosphorous is often limited in the sand-based rootzone turfgrass system, because many
fertilizers for mature turfgrasses have a low P analysis (Carrow et al., 2001)
P leaching and runoff cause an economic loss to homeowners and a nutritional loss to
turfgrass. Excessive P concentration is the most common cause of eutrophication in freshwater
3−

(Correll, 1998; Noe et al., 2001). PO4 –P concentration in excess of 0.024 mg L

6

−1

are favorable

for eutrophication in the temperate northeast America (Owens, 1998). Easton and Petrovic (2004)
compared natural organic and synthetic organic nutrient sources applied at rates of 50 and 100 kg
−1

N ha

per application (200 kg ha

−1

−1

yr ). The authors observed that fertilizers with higher P

content had higher P losses. However, very little of the applied P was recovered in clippings,
runoff, or leachate, suggesting much of the applied P remains in the soil, roots, and/or plant
tissue. They also observed an equal or higher amount of N and P losses in runoff and leachate
from the untreated control, supporting that establishment fertilization can reduce water
contamination from N and P. For urban landscape system, the cumulative mean of P leached
from St. Augustinegrass [Stenotaphrum secundatum (Wait.) Kuntze] urban lawn was 22.9 kg
−1

ha

during 45 months, which is high enough to raise concern on ecological impacts on urban

landscape systems (Erickson et al., 2005). Leaching losses were high during establishment and
following intense precipitation, and were also affected by species type and fertilizer protocols
(Erickson et al., 2005). Runoff loss of P from turfgrass shortly after P application ranges from <
1% to 18% of P fertilizer applied (Soldat and Petrovic, 2008). Turfgrasses grown on low Cation
Exchange Capacity (CEC), acid sands are susceptible to P leaching. Therefore, the use of a
-1

spoon-feeding method of 12.2−24.4 kg P2O5 ha with two to six applications per year is
recommended for this condition (Hull, 1997).
-1

For a mature turfgrass stand, P fertilizer should be applied less than 48.8 kg P2O5 ha to
minimize the possibility of leaching and runoff (Hull, 1997). Bierman et al. (2010) studied on P
fertilization and clipping management on P runoff on Kentucky bluegrass (Poa pratensis L.).
The authors concluded that reduced turfgrass quality will result in greater runoff depth for the no
fertilizer treatment than P fertilizer treatments, and P runoff can be reduced by not applying P to

7

-1

high testing soils (27 mg kg Bray P) and by avoiding fall applications. The addition of ferrous
sulfate as soil amendment may greatly reduce reactive phosphorus (< 0.45) runoff losses from
manure applications through a sod surface and has great potential to be used on turfgrass
(Torbert et al., 2005). There is limited research on the long-term effect of fertilization on P
leaching from turfgrass (Easton and Petrovic, 2004; Soldat and Petrovic, 2008).

Turfgrass Potassium fertilization
Potassium (K) is usually considered the second most important nutrient behind N in
turfgrass (Carrow et al., 2001). It increases turfgrass tolerance to drought, wear, disease, salinity,
cold (Turner, 1992), and heat (Beard, 1973) stresses. K does not directly affect turfgrass clipping
-1

-1

yield, and quality. However, higher K rates (162 and 243 kg ha yr ) increase N recovery and
use efficiency (Fitzpatrick and Guillard, 2004). Increasing N:K ratio beyond 1:0.5 did not result
in better turfgrass growth, appearance, or root weight, and did not increase K in turfgrass tissue
(Snyder and Cisar, 2000). N:K ratio higher than 1:1 will result in excess soluble salts in the
sandy soils. This salinity buildup will cause physiological drought and wear stress, especially
when rainfall or irrigation is limited (Carrow et al., 2001)
High K application may reduce soil and turfgrass calcium (Ca) and magnesium (Mg)
levels on hybrid bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt Davy], as
the Ca and Mg cation exchange sites in soil are replaced by K (Miller, 1999). For calcareous
soils with a low CEC, high rates of K application can also reduce plant available Ca and Mg in
leaf tissue, and in extractable soil Ca and Mg when using 1:5 H2O and 0.01 M SrCl2 extractions
(Woods et al., 2005).

8

Snyder and Cisar (2005) studied on K fertilization responses as affected by sodium (Na)
-2

in Florida, indicates that the Na fertilizer application at the rate of 5.0 g m on a molar adjusted
basis generally has no effect on bermudagrass quality and growth. Tissue Na concentration
-2

increased with decreasing K fertilizer application (0, 1.25, 2.5 and 5.0 g m ), and was markedly
greater in the no K fertilizer treatment.

Soil and Tissue Nutrient Analysis
Soil and tissue nutrient status are two key factors in diagnosing turfgrass problems. Soil
nutrient analysis is the primary means of assessing available nutrients for turfgrass and is
primarily used in developing guidelines for fertilization programs (Carrow et al., 2001). Tissue
analysis is used as a diagnostic tool. Soil test calibrations used for crops are fairly reliable, which
is based largely on yield response and crop quality. However, very little research on turfgrass
has been conducted for precise calibration and interpretation (Shuman, 2002; Petrovic et al.,
2005). Petrovic et al. (2005) researched the relationship between extractable soil and tissue P and
K concentrations with turfgrass quality and shoot growth at three sites in the New York. The
authors concluded that N, P, and K tissue levels were not well correlated with turfgrass quality,
and the application of K alone did not increase tissue K content. Additionally, they pointed out
that current soil K interpretations are too high, which needs to be reevaluated, and N application
amount may affect P and K recommendations.
Calcium (Ca), Magnesium (Mg) and Sulfur (S) are secondary nutrients behind N, P, K.
Ca is an important element in plant cell wall structure, and in membrane system inside cells. Ca
deficiency is rare on turfgrass, and there is no need to apply extra Ca to creeping bentgrass
grown on calcareous sands (St John et al., 2003). Mg and S deficiencies are sometimes observed

9

on turfgrass grown on high sand based rootzones. Tissue and soil extractable Ca and Mg can be
–1

reduced by high rates of K fertilizer in sand-peat (390 kg K ha
–1

-1

month ) and loamy sand (195

-1

-2

kg K ha month ) rootzones (Miller, 1999), as well as in calcareous sand rootzone (6 g K m
-1

14 d ) (Woods et al., 2005). Mg is the central atom in the chlorophyll molecule, and plays a
crucial role in plant photosynthesis. Soluble salt forms of Mg can be applied if detecting Mg
deficiency. However, excess Mg levels can induce K or Ca deficiencies, especially on low CEC
rootzones (Carrow et al., 2001). S is an essential element for many proteins and plant synthesis
2-

0

precursor. Turfgrass sites often receive S additions in uptake of SO4 from other fertilizers. S is
also recommended for turfgrass (Beard, 1973; Vargas, 2005). However, Berndt and Vargas Jr.
0

(2008) identified that adding S to greens with low redox may result in a rapid formation of S

2-

,and thereby an accelerated rate of black layer development. The authors suggested that either
0

3-

limiting the input of S or encouraging high soil redox through fertilizing with nitrate (NO ) and
aerifying.
Micronutrients required for turfgrass are iron (Fe), manganese (Mn), zinc (Zn), copper
(Cu), boron (B), molybdenum (Mo), chlorine (Cl), and nickel (Ni). Sodium (Na) and silicon (Si),
which are nonessential elements, also influence turfgrass growth under some conditions. Levels
of these nutrients are interacting to each other. For example, high soil levels of Fe, Cu, Zn or Na
can inhibit Mn uptake, while high Mn can reduce uptake of Fe, Mg, and Ca (Carrow et al., 2001).
-

McCrimmon et al. (1992) found that NO3 form application had higher concentrations of most
macro- and micronutrients and greater nutrient uptake in turfgrass shoot and root tissue
+

compared to the NH4 treated plants. Nitrogen and potassium applications affect most

10

macronutrient and micronutrient content in zoysiagrasses (McCrimmon, 2000). Especially K, Ca,
and Mg concentrations were below sufficiency level, which indicates that these nutrients may
require supplemental fertilizers applications. Previous research have been conducted on turfgrass
micronutrient fertilization. Foliar Fe applications can improve annual bluegrass persistence in
shade (Stiegler et al., 2003). Xu and Mancino (2001a) identified that Fe fertilization levels
produced the higher color ratings did not result in higher shoot and root production in creeping
bentgrass (Agrostis palustris Huds.) and annual bluegrass (Poa annua L.). Mn fertilization
(MnSO4) effectively reduced take-all patch [Gaeumannomyces graminis (Sacc.) Arx. & D.
Olivier var. avenae (E.M. Turner) Dennis] severity when applied in April or in October
(Heckman et al., 2003). Mancino et al. (1999) identified that application of Mn and Zn can
reduce dollar spot (Sclerotinia homoeocarpa), and red leaf spot (Drechslera erythrospila)
-1

infection. Increased Zn fertilization levels (0, 2.5, 5.0, or 40 mg L Zn from ZnSO4) resulted in
increased shoot dry weight of creeping bentgrass and annual bluegrass, and shoot Zn
concentrations were higher in annual bluegrass than in creeping bentgrass at each Zn level (Xu
and Mancino, 2001b). Guertal et al. (2004) researched on B fertilization of turfgrass, and
concluded that dry weight of clippings, thatch depth, shoot density, and turf color were
unaffected by B fertilization in the loamy sand soil. However, B fertilization of bentgrass in
sand-based greens might be warranted. Silicon fertilizers may increase the P adsorption capacity
of sandy soil, and also transform plant-unavailable P into available forms (Matichenkov et al.,
2001). The authors observed the promoted bahiagrass (Paspalum notatum Fluegge) growth by
20-100% and reduced P leaching by 40-70% in cultivated spodosols, alfisols, and entisols in
Florida.

11

Soil analysis
Different laboratories may have different soil test results because of different methods
used to measure pH and lime requirements, and different extracting solutions to extract available
nutrients (Brown, 1987). As a result of the ever-changing forms of N in soil, routine soil testing
does not include soil N (Carrow et al., 2001). However, it is still important to understand the
effects of N fertilization when soil and tissue test calibrations are being made (Petrovic et al.,
2005), because N fertilization on turfgrass is known to significantly affect turfgrass growth,
shoot density, color, and stress tolerance (Beard, 1973; Turner and Hummel, 1992). A normal
soil test will include pH and extractable P, K, Mg, and Ca.
“Sufficiency level of available nutrients” (SLAN) and “Basic cation saturation ratio”
(BCSR) are two concepts for soil testing (Carrow et al., 2001). SLAN, which measures the
amount of available nutrient in ppm to determine fertilization needs, is the traditional way of
predicting the total amount of available nutrients. BCSR uses the percentage saturation of basic
cations (K, Mg, and Ca) as a guide to determine the rates of fertilization. Arguments on which
method is more effective and accurate exist among scientists (Liebhardt, 1981). The BCSR
theory tends to be more misleading on low CEC soils, such as calcareous or silica sand-based
rootzone (St.John, 2007). Nutrient deficiency may still exist even if the BCSR theory identifies a
rootzone containing exchangeable cations in the correct proportions. St. John and Christians
(2007) observed K saturation percentage of silica sand samples were > 28%, yet the leaf and soil
-1

-1

extractable K were <21 g kg and <1.6 mg kg , which are deficient.
An extracting solution removes exchangeable cations on CEC sites. The Bray P1
extractant (0.03 M NH4F + 0.025 M HCl) and Mehlich III extractant (0.015 M NH4F + 0.2 M
NH4NO3 + 0.013 M HNO3 + EDTA) are widely used for assessing plant available P (Plank,

12

2001). In addition, Olsen extractant (0.5 M NaHCO3 at pH 8.5) is mostly used for P in
calcareous and alkaline soils. For soil K, 1M ammonium acetate (NH4OAc) is the mostly used
(Haby, 1990; Plank, 2001), with various other extractants available, such as Mehlich I (0.05 M
H2SO4 + 0.05 HCl), Mehlich III, and Morgan (0.2 M CH3COOH + 0.25 M NH4NO3 + 0.015 M
NH4F + 0.013 M HNO3 + 0.001 M EDTA) extractants. Extracting solutions for Ca and Mg are
commonly Mehlich III, Morgan, and NH4OAc (Carrow, 2004).

Tissue analysis
Turfgrass tissue testing can be used as a tool to evaluate nutrient levels in plant and relate
them to fertilization recommendations (Duble, 1977). Tissue test is useful for perennials, because
it might be too late to take actions for annual crops when symptoms occur after tissue analysis
(Carrow, 2000). Contrast to soil test, tissue test values should be the same regardless of the
method used, because it measures the total plant nutrient content by percentage. However,
limited research has been focused on the relationship between tissue analysis values and density,
color and growth on turfgrass (Carrow et al., 2001). Data for tissue interpretation can be referred
to forage and crops, which recommendation would be more affected by animal health and yield
productivity. Common sufficiency range for turfgrass tissue N is 2.8-3.5% dry weight; for tissue
P: 0.2-0.5%; tissue K: 1.5-3.0% (Carrow et al., 2001). These values vary with different turfgrass
species and cultivars and require further research for specific ranges.

13

Turfgrass Rootzone and Soil Property
Maintaining sufficient nutrient in the rootzone is one of the principals for a healthy turf
(Happ, 1995). Recreational turfgrass sites, such as golf course putting green or athletic fields,
usually adopt the United States Golf Association (USGA) specification rootzone, which is sandbased, well-drained, and has less potential for compaction (Green section stuff, 2004). However,
its high macroporosity leads to easy nutrient loss through leaching (Bigelow et al., 2001; Petri
and Petrovic, 2001), and therefore pose a significant problem of nutrient retention, especially for
the establishment year (Carrow et al., 2001). Organic matter then accumulates overtime leading
to the loss of macropores in the rootzone (Davis, 1990; Duble, 1996; Heback, 2000; Curtis,
2001), which reduces water infiltration, leaching, and improves CEC and nutrient retention.
There is a limited research on nutrient dynamics in sand-based rootzones with time (McClellan et
al., 2007).

Soil amendments
The sand is usually amended with organic matter to improve moisture and nutrient
retention, as well as maintaining rootzone drainage and compaction resistance (Waltz and
McCarty, 2005). However, particulate organic matter is associated with soil water repellency
(SWR) in the turfgrass system (Moody et al., 2009). The organic coatings on mineral
constituents are considered as the cause of hydrophobicity (Doerr, 2000). In maturing turfgrass
system, microbial decomposition of plant residues may facilitate the hydrophobic process and
enhance organic matter adsorption onto mineral surfaces (Hallett et al., 2001). Soil organisms
such as basidiomycete fungi may cause severe SWR by producing hydrophobic fungi (Fidanza et

14

al., 2007); and then SWR would reduce irrigation and fertilizer efficiency, seed germination, and
pesticide response (Doerr, 2000).
There is a trend of replacing organic matter with inorganic soil amendments, such as
zeolite and polypropylene fibers, in golf course putting greens and athletic fields. Several studies
(Horn, 1969; Minner et al., 1997; Bigelow, 1999) were conducted on calcined clay as a sole
amendment on sandy soil, yet poor turfgrass performances were reported. The reason is that
calcined clay amended sand caused water bound at high tension and therefore unavailable to the
plant. Additionally, Waltz Jr et al. (2005) compared soil and turfgrass performance on rootzones
amended with Canadian sphagnum peat (organic CSP), calcined clay, and diatomaceous earth,
concluding the organic CSP was the best amendment for a better turfgrass cover and quality, the
earliest turf establishment, and reduced bulk density.

Playability
Ball Roll Distance
Ball roll distance (BRD) is a key factor of identifying putting green smoothness and
playability (Salaiz et al., 1995). Increased N rate application would decrease BRD because of the
excessive turf growth (Pease et al., 2011). However, Kopec et al (2007) determined that the BRD
-

was largely unaffected by N fertilization with the rate ranging from 12, 18, 24, and 36 kg N ha
1

-1

month , but was consistently affected by mowing height and rolling. Nikolai et al (2001) also

suggested lightweight green rolling would significantly increase ball roll distance, as well as
reduce dollar spot (Sclerotinia homoeocarpa), moss growth, and bird activity. Moreover, lower
soil P values on calcareous sand greens resulted in longer ball roll distance (Johnson et al., 2003).

15

Wear Tolerance
Traffic on turfgrass surface can cause wear and soil compaction (Carrow, 1992), and
turfgrass wear accounts for 90% of injury compared with soil compaction (Dest, 2009). Fertility
is one of the management strategies to improve wear tolerance (Hoffman et al., 2010). A number
of studies have evaluated wear tolerance in creeping bentgrass, and previous studies have found
that velvet bentgrass has better wear tolerance than creeping bentgrass and other Agrostis species
(Dowgiewicz et al., 2011).
-1 -1

Increased N fertilization (96, 192, 392 kg N ha yr ) increases wear tolerance in
-1 -1

creeping bentgrass (Carroll, 1991; Trenholm et al., 2001a). High level of K (392 kg K ha yr )
increase wear tolerance because of the increased turgidity and reduced tissue succulence (Beard,
1973). However, research also shows no influence of K on wear tolerance in both cool season
and warm season grasses (Carroll, 1991; Trenholm et al., 2001a).
Silicon (Si) could also improve wear tolerance. Si deposition in the cuticle and lignin
polymers improves leaf and stem strength (Takahashi et al., 1990; Hull, 2004). However,
Trenholm et al. (2001b) pointed out that increasing Si level would reduce turfgrass quality score.
The authors also indentified that K alone fertilizer application had the same or better effect on
wear tolerance than Si applied as foliar potassium silicate on seashore paspalum (Paspalum
vaginatum Swartz).

Dollar Spot Suppression
Dollar spot (DS), caused by Slerotinia homoeocapa F.T. Bennett, is a widespread disease
that affects all turfgrasses from home lawns to putting greens (Vargas, 2005). DS has been
reported as more severe under low N fertility (Smiley, 2005; Vargas, 2005).

16

There were inconsistent results on DS suppression by using organic fertilizers. Liu et al
(1995) found that organic fertilizers reduce DS severity on creeping bentgrass similarly to
chlorothalonil. However, the authors did not apply the fertilizers at a uniform rate (50-260 kg N
-1

ha ). As a result, their observation of dollar spot suppression might have been influenced by the
increasinged N rates of fertiliers applied, which might allow the turf to recover more rapidly
from the disease.
Landschoot and McNitt (Landchoot, 1997) compared the effects of natural organic
fertilizers, urea, and ureaform on dollar spot suppression, showing that creeping bentgrass
fertilized with urea had equal or better dollar spot suppression than that of receiving natural
organic fertilizers. Davis and Dernoeden (2002) compared nine N sources by using the
−1

recommended N rate (200 kg N ha

−1

yr ) on southshore creeping bentgrass fairway for seven

years. Their results showed that the Ringer Lawn Restore (Ringer LR, Ringer Corporation,
Minneapolis, MN) and urea treatments suppressed DS, while the Com-Pro (Blue Plains
Sanitation Commission, Silver Spring, MD) enhanced it. Boulter et al (2002) identified that
application of compost products on creeping bentgrass reduced DS incidence to a level similar to
conventional fungicides. However, Lee et al (2003) indicated that it is less likely to maintain
good bentgrass putting green quality without fungicides at the place where DS pressure is
significant in Kansas.

Annual Bluegrass Invasion
Annual bluegrass (Poa annua) invasion of bentgrass greens is a universal problem for
golf course superintendents. Currently, no products available can completely prevent annual
bluegrass from invading newly seeded bentgrass greens. Herbicides and plant growth regulators

17

are the commonly used methods for regional annual bluegrass control (Beard, 1978; McCullough,
2005).
There were a few studies on turfgrass fertilizer effects on annual bluegrass invasion.
Hardt and Schulz (1995) found that ureaform-fertilized bentgrass was more susceptible to annual
bluegrass invasion than IBDU and natural organic N applications. Low level of soil P might
contribute limiting annual bluegrass invasion, because bentgrass was able to fix P from deep soil
where annual bluegrass roots could not reach (Stowell, 2005).

18

MATERIALS AND METHODS
Research was conducted at the Hancock Turfgrass Research Center at Michigan State
University on a putting green measuring 36 x 36 m with three rootzones. Each rootzone had
three greens measuring 11 x 11 m, and an 11 x 1.8 m buffer area between them. The three
rootzone mixes were (1) 80:20 (sand:peat, v/v) mixture constructed to USGA specification, (2)
80:10:10 (sand:peat:soil, v/v) mixture with subsurface tile drainage, and (3) undisturbed sandy
clay loam (58% sand, 20.5% silt, and 21.5% clay) native soil.
The rootzones were constructed in 1993. In 2007, Glyphosate was applied, sod was
stripped and 5 cm of topdressing was removed. In 2008, the site was seeded with Penn A-4
creeping bentgrass (Agrostis palustris Huds.). In June 2009, fertilizer treatments were initiated.
Experimental design of the research was a Randomized Complete Block Design with
three replications. Treatment design was a split-plot. Data were analyzed through mixed effects
analysis of variance using PROC MIXED in SAS (SAS Institute, 2002). Fertilizer treatments and
rootzones were the two factors. Analysis of Variance was used to determine significant effects.
When significant differences were detected (P < 0.05), the least square means were separated
using LSMEANS procedure.
Each rootzone was split into nine 11 x 1.2 m plots for nine fertilizer treatments (Table 1). The
nine fertilizer treatments were: an all natural organic (Organic) (10N-2P-4K), a methylene urea
(MU) (40N-0P-0K), a urea (46N-0P-0K), a urea with phosphorous (P) soil test recommendation
(calcium phosphate 100%, CaHPO4), a urea with potassium (K) soil test recommendation [Pro
Turf Super K (0N-0P-45K)], Grigg Bros. Gary's Green (18N-3P-4K) foliar at two rates (1xF and
2xF), Grigg Bros. Gary's Green (18N-3P-4K) foliar with Grigg Bros. Turf Rally (16N-4P-8K)

19

Table 1. Treatment design and research plot map.
Rep3

7

9

6

5

1

3

4

2

8


 3

6

9

1

USGA

Rep2

6

3

2

9

8

1

6

1

3

2

2

5

8

7


 2

7

4

4

7

5


 8

1

4

7

9

2

3

6

9

5


 4

5

2

3

Native

4

7


 5

4

6

3

9

7

6

5

1

9

8

1

6

9

4

3

1

80-10-10

7

8

USGA

Rep1

5

1
2
3
4
5
6
7
8
9

Untreated control
Grigg Bros. all natural organic (10-2-4)
Methylene urea (40-0-0)
Urea (46-0-0)
Urea+ P soil test recommendation (CaHPO4)
Urea + K soil test recommendation [Pro Turf Super K (0-0-45)]
Grigg Bros. Gary's Green (1xF) (18-3-4)
Grigg Bros. Gary's Green (1xF) (18-3-4) + Grigg Bros. Turf Rally (16-4-8)
Grigg Bros. Gary’s Green (2xF) (18-3-4)

USGA

3

Native

80-10-10

8

4

2

1

8


 5

6

80-10-10

20

8

9

7

2

Native

granular (Combination), and an untreated control (UC). The organic fertilizer is derived from soy
protein and blood meal.
-1

The organic, MU, and urea were applied at the rate of 24.4 kg N ha per application at
the beginning of each month from May through October. The 1xF was sprayed at the rate of 6.1
-1

-1

kg N ha and 2xF 12.2 kg N ha per application biweekly from May through October. The Turf
-1

Rally granular was applied at the rate of 12.2 kg N ha per month. All the treatments received
-1

the same amount of total annual N of 146.4 kg N ha , except the 1xF treatment, which received
-1

73.2 kg N ha (Table 2).
CaHPO4 as P source and Pro Turf Super K as K source were added accordingly to the
urea+P and urea+K treatments in 2010 and 2011 based on the soil P and K test recommendations
from October 2009 and 2010 (Tables 3 and 4). CaHPO4 was sprayed once a month at the
-1

beginning of June, July, August, and September at the rate of 13.4 kg P2O5 ha in 2010, and
-1

19.5 kg P2O5 ha in 2011. Granular Pro Turf Super K was applied monthly from June through
-1

-1

September at the rate of 69.5 kg K2O ha in 2010 and 67.1 kg K2O ha in 2011.
Turfgrass color and quality were rated visually every week from May through October on
a scale of 1 to 9 (1-poor, 6-acceptable, 9-best for quality) (1-straw brown, 6-acceptable, 9-dark
green for color). Chlorophyll ratings were taken weekly using the Field Scout TCM 500 Turf
Color Meter (Spectrum Technologies Inc.), which measures light reflectance in the red and nearinfrared spectral bands to calculate an objective color evaluation of turf. Chlorophyll indexes
were expressed as 3 digit numbers, where a higher number indicates a relatively greener color,
and a lower number indicates a relatively yellower color. The use of the TCM 500 Color Meter

21

for chlorophyll readings provides a quantitative measurement of turfgrass color.	
  	
  
Ball roll distance was measured from July through September by rolling three golf balls
from a Pelzmeter (Pelz Golf Institute). The bubble-level system implemented on the Pelzmeter
ensures that the ball is released from a consistent height, therefore reducing variability. The
tapered ramp minimizes ball bounce where the ramp meets the turf. The Pelzmeter’s three sideby-side grooves allow rolling three balls at a time and help to minimize ball-tracking effects
(Pelzmeter User Mannual, 2004). In this study, three golf balls were rolled at the same time from
the Pelzmeter on one end of the plot, and then rolled again from the other end of the plot so as to
avoid slope effect within a plot. The six distances were averaged to obtain one ball roll distance
for each plot, and reported in cm.
Water infiltration tests were conducted in October using double-ring infiltrometers. The
inner ring was 12.7 cm and the outer ring was 21.3 cm in diameter. The water level in the outer
ring was maintained at a constant level to prevent leakage between rings and to force vertical
infiltration from the inner ring. The water level in the inner ring was also kept at a fixed level,
and the volume of water needed to maintain this level was measured. Water level was recorded
every five minutes for an hour and results reported in cm hr-1 (Gregory et al., 2005).
Turfgrass diseases and weed occurrence were also rated. Dollar spot (Sclerotinia
homeocarpa) was visually assessed as number of dollar spot infection centers per plot from July
through September. Worm castings were counted when observed before mowing from July
through September. Annual bluegrass (Poa annua) was counted on May 20, 2011.

22

Table 2. Fertilizer treatments.

-1

Nigrogen rate (kg N ha )

†
‡
§

Name
Untreated control
All natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium
‡
1xF
Combination
§
2xF

Per application
NA†
24.4
24.4
24.4
24.4
24.4

Per month
NA
24.4
24.4
24.4
24.4
24.4

Annual total
NA
146.4
146.4
146.4
146.4
146.4

6.1
6.1(Foliar)+12.2(Granular)

12.2
24.4

73.2
146.4

12.2

24.4

146.4

No fertilizer application.

-1

Gary’s Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary’s Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.

23

Table 3. Phosphorous (P2O5) recommendation for the Urea+phophorous treatment from soil test
results of October 2009 and 2010.
-1
Recommend phosphorous (P2O5) kg ha
Replication
Soil type
2009
2010
†
1
USGA
NR
39.0
1
80-10-10
NR
NR
1
Native
NR
NR
2
USGA
53.7
78.0
2
80-10-10
NR
NR
2
Native
NR
NR
3
USGA
NR
83.0
3
80-10-10
NR
NR
3
Native
NR
NR
†
No recommendation, P levels from soil test were at or above optimum

24

Table 4. Potassium (K2O) recommendation for the Urea+K treatment from soil test results of
October 2009 and 2010.
-1
Recommend potassium (K2O) kg ha
2009
Replication
Soil type
2010
1
USGA
278.2
268.4
1
80-10-10
263.5
258.6
1
Native
180.6
190.3
2
USGA
278.2
248.9
2
80-10-10
258.6
170.8
2
Native
122.0
263.5
3
USGA
273.3
258.6
3
80-10-10
273.3
141.5
3
Native
165.9
253.8

25

Turfgrass soil and tissue samples were collected on the same days in June and October
from 2009 to 2011. Samples were dried in a convention oven for 72 h at 60 °C. Oven-dried tissue
samples were then weighed before a complete nutrient analysis. Soil samples were collected to a
depth of 10 cm, and verdure and thatch were removed. Each plot was split into five equal
sections, one section for each year to avoid soil sampling from a previously disturbed area. All
the samples were sent to the Soil and Plant Nutrient Laboratory at the Department of Crop and
Soil Sciences, Michigan State University (East Lansing, MI).
Soil P was measured by using Bray P1 extractant (0.03 M NH4F + 0.025 M HCl) when
pH equals or less than 7.4, or Olsen extractant solution (0.5 M NaHCO3) when pH is greater than
7.4. Soil K, Ca, and Mg were tested by using 1M ammonium acetate (NH4OAc). Soil total N
(not including nitrates) was determined with the LaChat Rapid Flow Injection Unit using the
ammonia-salicylate method after going through the Micro-Kjeldahl Block Digestion process.
Soil nitrate-N was extracted by 1 M KCl (Manual of Laboratory Procedures).
Tissue analysis was conducted in the A&L Great Lakes Laboratories Inc. (Fort Wayne,
Indiana). Tissue total N was measured using the Dumas Method (nitrogen by combustion or
nitrogen by thermal conductance). Mineral nutrients were analyzed using the Inductively
Coupled Argon Plasma (ICAP) after going through Mineral Digestion (Open Vessel Microwave)
(Plant Tissue Analysis Method Summary).
The plots were mowed at a height of 35 mm five days a week with a walk-behind Toro
Greensmaster 1000 (Toro Co., Bloomington, MN). Topdressing with fine sand (>60% 0.25-1.0
mm) was applied weekly from June through September.

26

RESULTS AND DISCUSSION
Soil Nutrient Analysis
Nitrate Nitrogen
There was a significant rootzone x sampling date interaction for NO3-N soil test values
(Table 5). The native soil rootzone had higher soil NO3-N concentration than the USGA and 8010-10 rootzones at all sampling dates, except for June 2010 when there were no significant
differences (Table 6). The largest amount of soil NO3-N for rootzones was detected at the
October 2011 sampling date, with 2.29 ppm for the USGA rootzone, 2.31 ppm for the 80-10-10
rootzone, and 4.33 ppm for the native soil (Table 6). The native soil rootzone resulted in high
soil nutrient values because of its high water and nutrient retention ability. Clay particles
(colloids) in the native soil also attribute to high soil nutrient because of its high CEC (Carrow et
al., 2001).
There was a significant fertilizer treatment effect for soil NO3-N (Table 7). The granular
fertilizer treatments (natural organic, methylene urea, urea, urea+P, and urea+K) had the highest
soil NO3-N content. The untreated control had the lowest NO3-N concentration but was not
significantly different from the foliar and combination treatments (1xF, 1xF+ granular, and 2xF).
Foliar application of nitrogen fertilizers results in lower soil nutrient concentration because
research has shown that 30 - 60% of applied fertilizer is absorbed by turfgrass tissue (Liu, 2005;
Totten, 2006a).

27

Total Nitrogen
There was a significant rootzone effect across all sampling dates for soil total nitrogen (Table 5).
The native soil rootzone had the largest amount of total nitrogen of 0.09%, following with 0.05%
and 0.03% for the 80-10-10 and USGA rootzones, respectively (Table 8). The native soil has
21.5% clay content. Therefore the CEC associated with the clay, and organic matter bound to the
clay result in higher soil NO3-N and total N values. There was no difference among fertilizer
treatments for soil total N content for all sampling dates (Table 5).

Phosphorus
There was a significant rootzone x sampling date interaction for soil P test values (Table
5). The USGA rootzone had a smaller amount of soil P than the 80-10-10 and the native soil
rootzones (Table 9). Soil P content for the USGA rootzone was below sufficiency level based on
turfgrass soil P recommendation (Soil and Plant Nutrient Laboratory, MSU). For the USGA
rootzone, soil P decreased from October 2009 to October 2011. Soil P values for the 80-10-10
and native soil rootzones were generally consistent throughout the sampling dates. Easton and
Petrovic (2004) concluded that very little of fertilizer applied P was recovered in clippings,
runoff, or leachate, and much of the applied P remains in the soil, roots, and/or plant tissue. In
this research, the USGA rootzone had decreasing soil P concentration (Table 9), and consistent
tissue P concentration over sampling dates (Table 16). Phosphorous is often limited in the sandbased rootzone turfgrass system, because many fertilizers for mature turfgrasses have a low P
analysis (Carrow et al., 2001). However, there was no significant difference among fertilizer
treatments for soil P content (Table 5), which implies the urea+P treatment did not result in a
higher soil P content than other fertilizer treatments. Easton and Petrovic (2004) observed less

28

Table 5. Analysis of variance for soil nitrate nitrogen (NO3-N), total nitrogen (Total N),
phosphorus (P), and potassium (K) of Penn ‘A-4’ creeping bentgrass in 2009, 2010, and 2011.
Soil nutrient test
Contrasts
NO3-N
Total N
P
K
Pr>F
Rootzone (R)
*
*
*
*
Fertilizer treatment
(F)
*
NS
NS
*
RxF
NS
NS
NS
*
Sampling date (S)
*
*
*
*
RxS
*
NS
*
*
FxS
NS
NS
NS NS
RxFxS
NS
NS
NS NS
* and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

29

Table 6. Lsmean soil nitrate nitrogen (NO3-N) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Soil NO3-N (ppm)
Rootzone
† ‡ 1.26B
0.41dD 0.51dD 2.29bA
0.59c C
USGA
80-10-10 1.03bC
1.73B 0.61abC 0.81bC 2.31bA
Native
1.92aB 1.40BC 0.97aC 1.21aC 4.33aA
†
Lower case letters represent significant differences at the 0.05 probability level in columns.
‡

Capital letters indicate significant differences at the 0.05 probability level in rows.

30

Table 7. Lsmean soil nitrate nitrogen (NO3-N) for the fertilizer treatment effect of Penn ‘A-4’
creeping bentgrass.
Soil NO3-N
Fertilizer treatments
ppm
Untreated control
1.22b†
Natural organic
1.69a
Methylene urea
1.64a
Urea
1.54ab
Urea+phosphorous
1.45ab
Urea+potassium
1.49ab
‡
1.23b
1xF
1xF+granular
1.29b
§
1.29b
2xF
P value
0.03
†
Letters represent significant differences at the 0.05 probability level.
‡
§

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

31

soil N and P concentration on the untreated control from a Arkport sandy loam soil. However, in
this research, the untreated control did not result in lower soil P concentration than other
fertilizer treatments on any of the rootzones.

Potassium
There was a significant rootzone x sampling date interaction for soil potassium test
values (Table 5). The native soil rootzone had the highest soil potassium values for all sampling
dates (Table 10), and the USGA rootzone had the smallest amount of soil K. For the USGA
rootzone, the October 2011 sampling date had the lowest soil K value compared with other dates.
The June 2011 sampling date had the largest concentration of soil K for the 80-10-10 and the
native soil rootzones (Table 10).
There was a significant fertilizer treatment x rootzone interaction for soil K (Table 5).
The native soil had higher K concentration than the USGA and 80-10-10 rootzones across all
fertilizer treatments (Table 11). For the Urea+K treatment among the rootzone, the USGA
rootzone had the lowest soil K value (Table 11). Potassium moves more readily in sandy soils
with lower CEC than finer-textured soils (Carl J. Rosen, 2008). Therefore, turfgrass grown on
the USGA rootzone tends to absorb K easier from the soil, resulting in lower K concentration on
the USGA rootzone for the urea+K treatment. Moreover, high macroporosity of the USGA
rootzone leads to easy K loss through leaching (Bigelow et al., 2001; Petri and Petrovic, 2001).
There were no significant differences among fertilizer treatments for the USGA and 8010-10 rootzones. For the native soil rootzone, the natural organic, methylene urea, urea, 2xF, and
the untreated control had the highest soil K values, and the urea+P treatment had the lowest
concentration of soil K. The native soil with 21.5% clay content had higher Cation Exchange

32

Table 8. Lsmean soil total nitrogen (N) for the rootzone effect of Penn ‘A-4’ creeping bentgrass.
Soil total N
Rootzone
%
†
0.03b
USGA
80-10-10
0.05b
Native
0.09a
P value
<0.01
†

Lower case letters represent significant differences at the 0.05 probability level.

33

Table 9. Lsmean bentgrass soil phosphorus (P) for the rootzone x sampling date interaction.
Sampling date
October
October
October
2009
June 2010
2010
June 2011
2011
Soil P (ppm)
Rootzone
† ‡ 17.18bB
14.66bC 16.04BcC 14.52cC
19.43b A
USGA
80-10-10
48.33aA 43.41aAB 45.70aAB 44.67bAB 39.96bB
Native
54.76aA
51.33aC
51.89aB 57.48aAB 54.33aAB
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

34

Capacity (CEC), resulting in higher K levels. A high soil K concentration for the untreated
control could be caused by less turfgrass growth, thereby less tissue K absorption.

Tissue Nutrient Analysis
Nitrogen
There was a significant fertilizer treatment x sampling date interaction for tissue total
nitrogen (Table 12). The urea, urea+P, and urea+K treatments had the largest amount of tissue
total N for the October 2010 and the October 2011 sampling dates (Table 13). The untreated
control had the lowest amount of tissue total N for all sampling dates (Table 13). Application of
quick-release nitrogen often leads to higher N uptake by turfgrass (Landschoot and Waddington,
1987). In October when weather condition is more favorable for the root growth of creeping
bentgrass, root absorption of nutrient is more effective than foliar absorption, thus quick-release
N fertilizer resulted in higher N concentration than foliar N application.
There was a significant rootzone x sampling date interaction for tissue total nitrogen values
(Table 12). The native soil rootzone had the lowest tissue total N values for the October 2010,
June 2011, and October 2011 sampling dates (Table 14). These tissue N values (1.23, 2.11,
1.63%) were below turfgrass common sufficiency range of 2.8-3.5% (Carrow et al., 2001). This
result is contrary to soil N test results, that the native soil rootzone had the largest soil NO3-N
and soil total N concentration (Tables 6 and 8). These results suggest that the concentration of
soil nitrogen is not reflected in tissue nitrogen. However, soil N tests are not usually used to
recommend N application rates for turfgrass.

35

Table 10. Lsmean soil potassium (K) for the rootzone x sampling date interaction.
Sampling date
October
October
June
October
2009
June 2010
2010
2011
2011
Soil K (ppm)
Rootzone
†
‡ 17.78cA 19.33cA 18.33bA 13.18bB
16.67c AB
USGA
80-10-10
21.86bB
25.29bAB 22.33bB 27.11bA 17.63bC
Native
86.57aA
75.15aB 76.89aB 88.92aA 75.29aB
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

36

Table 11. Lsmean soil potassium (K) for the rootzone x fertilizer treatment interaction.
Rootzone
USGA 80-10-10
Native
Fertilizer treatment
Soil K (ppm)
‡
†
22.40B
84ab A
Untreated control 16.53B
Natural organic
17.73B
24.86B
89.66aA
Methylene urea
17.20B
21.13B
84.66abA
Urea
15.93B
19.86B
84.00abA
Urea+phosphorous 14.53B
19.80B
63.53dA
Urea+potassium
17.33C
27.53B
77.46bcA
§
18.73B
23.93B
80.33bcA
1xF
1xF+granular
19.06B
24.33B
72.06cdA
¶
16.06B
21.73B
82.60abA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

37

Phosphorous
There was a significant fertilizer treatment x sampling date interaction for tissue
phosphorous (Table 12). The methylene urea, urea, urea+P, urea+K, and 2xF had the highest
tissue P values for the Ocotober 2010 sampling date (Table 15). The urea+P, 1xF+granular, and
2xF treatments had the highest amount of tissue P for the October 2011 sampling date. The
urea+P and 2xF treatments maintained the high P concentration on both October 2010 and
October 2011 sampling dates. This result suggests that the 2xF treatment had similar effects in
improving tissue P content as P supplement in the Urea+P fertilizer treatment.
There was a significant rootzone x sampling date interaction for tissue phosphorous
values (Table 12). The native soil rootzone had the lowest tissue P values for the October 2010
and October 2011 sampling dates (Table 16). This result suggests that high soil P does not result
in high turfgrass tissue P concentration, especially on the native soil (Tables 9 and 16). Plant
-

-

available P in the forms of H2PO4 and HPO4 in the soil solution can be utilized by microbial
activities and bound with Fe, Al, Mn, and Ca to cause insoluble P forms (Carrow et al., 2001).
The native soil rootzone with high Ca content could attribute to the low turfgrass tissue P, which
were below the sufficiency range of 0.2-0.5% (Carrow et al., 2001) on the October 2010 and
October 2011 sampling dates.

Potassium
There was a significant fertilizer treatment x sampling date interaction for tissue K (Table
12). The urea+K treatment had the highest tissue K concentration for the October 2010, June
2011, and October 2011 sampling dates (Table 17). This result suggests that additional K

38

Table 12. Analysis of variance for tissue nitrogen (N), phosphorus (P), and potassium (K) of
Penn ‘A-4’ creeping bentgrass in 2009, 2010, and 2011.
Tissue nutrient test
Contrasts
Total N
P
K
%
Rootzone (R)
*
NS
*
Fertilizer treatment
(F)
*
*
*
RxF
NS
NS
NS
Sampling date (S)
*
*
*
RxS
*
*
*
FxS
*
*
*
RxFxS
NS
NS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

39

Table 13. Lsmean creeping bentgrass tissue total nitrogen (N) for the fertilizer treatment x
sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue total N (%)
Fertilizer treatment
† ‡
Untreated control 3.08c B
3.65bA
1.45eC
1.79bC
1.44eC
Natural organic
3.37bB
3.95aA 2.10bcC 2.93aB
2.20cdC
Methylene urea
3.63aA
3.88aA 2.17bcC 3.01aB
2.69bB
Urea
3.45abA 3.06dAB 2.62aC 3.17aAB 2.95abBC
Urea+phosphorous 3.45abA 2.96dA 2.49abB 3.01aA
2.99aA
Urea+potassium
3.45abA 3.18dA
2.64aB
3.22aA
3.01aA
§
1xF
3.36bA 3.55bcA 1.51deC 2.68aB
2.02dB
1xF+granular
3.46abA 3.47cdA 1.88cdC 2.96aB
2.36cB
¶
2xF
3.51abA 3.67bA 2.18bcD 3.20aC
2.68bB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

40

Table 14. Lsmean bentgrass tissue total nitrogen (N) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue total N (%)
Rootzone
‡
†
3.44A
2.91B
2.85a B 3.33aA 2.95aB
USGA
80-10-10 3.64A
3.52A
2.27bD 3.22aB 2.86aC
Native
3.68A
3.51A
1.23cD 2.11bB 1.63bC
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

41

applications are effective in improving turfgrass tissue K across rootzones over time. The
untreated control had the lowest tissue K values across all sampling dates.
There was a significant rootzone x sampling date interaction for tissue potassium values
(Table 12). The native soil rootzone had higher tissue K content for the October 2009 and June
2010 sampling dates, but the lowest tissue K values for the October 2010, June 2011, and
October 2011 sampling dates (Table 18). Similar to tissue N and P results, high soil K does not
result in high turfgrass tissue K. These results suggest that tissue and soil analysis can not predict
each other, thus tissue test should be considered in making fertilization recommendations,
especially for critical areas such as golf greens.

42

Table 15. Lsmean tissue phosphorous (P) for the fertilizer treatment x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue P (%)
Fertilizer treatment
‡
†
0.51a A
Untreated control 0.39B
0.20cC
0.24C
0.19eC
Natural organic
0.44A
0.51aA
0.27bcB
0.42A 0.28bcdB
Methylene urea
0.45A 0.49abA 0.29abCD 0.38B 0.27bcdC
Urea
0.44A 0.40cAB 0.30abCD 0.36BC 0.27bcdD
Urea+phosphorous
0.44A
0.37cB 0.30abCD 0.37BC 0.29abD
Urea+potassium
0.44A
0.40cA
0.32aB
0.38AB 0.26dC
§
1xF
0.43AB 0.51aA
0.21cD
0.37B
0.26dC
1xF+granular
0.43AB 0.46bA
0.27bcC
0.41B
0.29abC
¶
2xF
0.43AB 0.50abA 0.30abC
0.41B
0.31aC
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

43

Table 16. Lsmean tissue phophorous (P) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue P (%)
Rootzone
‡
†
0.39A
0.40b A 0.32aB 0.38A 0.29aC
USGA
80-10-10 0.46A
0.47aA 0.31aC 0.42B 0.32aC
Native
0.44B
0.51aA 0.19bD 0.31C 0.19bD
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

44

Table 17. Lsmean tissue potassium (K) for the fertilizer treatment x sampling date interaction.
Sampling date
October
June
October
October
2009
2010
2010
June 2011
2011
Tissue K (%)
Fertilizer treatment
† ‡
Untreated control 1.34c A
1.21A
0.85cB
0.79eB
0.94eB
Natural organic
1.56abA
1.23BC
1.14bC 1.43bcdAB 1.30cdBC
Methylene urea
1.70aA
1.38B
1.24bB
1.35cdB
1.42bcB
Urea
1.68aA
1.08C
1.28bC
1.46bcB
1.45bB
Urea+phosphorous 1.68aA
1.00C
1.31bB 1.41bcdB
1.40bcB
Urea+potassium
1.68aB
1.21C
1.70aB
2.07aA
1.60aB
1xF§
1.50bA
1.24B
0.83cC
1.27dB
1.22dBC
1xF+granular
1.59abA
1.27B
1.17bB 1.44bcdA
1.43bcA
2xF¶
1.66aA
1.20B
1.27bB
1.47bA
1.51abA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

.

45

Table 18. Lsmean creeping bentgrass tissue potassium (K) for the rootzone x sampling date
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue K (%)
Rootzone
‡
†
1.41B
1.07b C 1.57aAB 1.50B 1.59aA
USGA
80-10-10 1.63A 1.24abB 1.34bB
1.58A 1.63aA
Native
1.69A
1.30aB 0.68cD
1.15B 0.87bC
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

46

Color, Quality, and Chlorophyll
There was a significant fertilizer treatment x rootzone x sampling date x year interaction
for turfgrass color, quality and chlorophyll ratings (Table 19). Therefore, these results are
discussed by each year. The turfgrass color, quality, and chlorophyll were rated 4 weeks after
fertilizer application, except for the foliar treatments, which were 2 weeks after the second
application.

Within years

2009
There was a significant fertilizer treatment x sampling date interaction for the 2009
turfgrass color ratings (Table 20). The urea treatment had the highest and the untreated control
had the lowest color rating for all sampling dates in 2009 (Table 21). All the color ratings were
above the acceptable level (>6), except for the untreated control in June and October (Table 21).
There was a significant rootzone x sampling date interaction for the 2009 turfgrass color
ratings (Table 20). In August and October, the native soil rootzone had higher color ratings than
the USGA and 80-10-10 rootzones (Table 22). All the rootzones had the lowest color ratings for
the June sampling date. The reason could be that the first fertilizer application was made in June.
There was a significant fertilizer treatment x sampling date interaction for the 2009
turfgrass quality ratings (Table 20). The urea treatment had the highest quality rating in June and
October 2009 (Table 23). This result is similar to the 2009 color rating except for the August
sampling date, which had no difference in quality rating among fertilized treatments (Table 23).

47

There was a significant rootzone x sampling date interaction for the 2009 turfgrass
quality ratings (Table 20). The 80-10-10 rootzone had the highest quality rating in August, while
the native soil had the highest quality rating in October 2009 (Table 24).
There was a significant fertilizer treatment effect for the chlorophyll ratings for 2009
(Table 20). The urea, 2xF, and methylene urea treatments had the highest chlorophyll ratings for
2009, and the untreated control had the lowest chlorophyll ratings (Table 25).
The 2009 results suggest that the urea treatment had the best turf color and quality for all
sampling dates in 2009. The double-rate foliar treatment had equal color and quality ratings with
the slow-release fertilizer treatments (natural organic and methylene urea). The combination and
single-rate foliar treatments had the lowest turfgrass color ratings among fertilized treatments in
2009.

2010
There was a significant fertilizer treatment x sampling date interaction for the 2010
turfgrass color ratings (Table 20). The granular fertilizer treatments had the highest color ratings
in April (Table 26). In May and June, the natural organic and methylene urea treatments had the
highest color ratings. For July and August sampling dates, the 2xF and 1xF+Granular treatments
had the highest ratings. The urea, urea+P, and urea+K treatments had the highest color ratings in
September and Ocotber 2010 (Table 26). These results suggest that granular fertilizer treatments
had better turfgrass color in late fall and faster green up in the spring. Foliar applications result in
better turfgrass color and quality for the summer time.

48

Table 19. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’ creeping
bentgrass.
Turfgrass color, quality, and chlorophyll
ratings
Contrasts
Color
Quality
Chlorophyll
Pr>F
Rootzone (R)
*
NS
NS
Fertilizer treatment
(F)
*
*
*
RxF
NS
NS
NS
Sampling date (S)
*
*
*
RxS
*
*
NS
FxS
*
*
NS
RxFxS
NS
NS
NS
Year (Y)
*
*
*
RxY
*
NS
NS
FxY
*
*
*
SxY
*
*
*
RxFxSxY
*
*
*
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level.

49

Table 20. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’ creeping bentgrass by year.
Turfgrass color, quality, and chlorophyll rating
2009
Contrasts

2010

2011

Color Quality Chlorophyll Color Quality Chlorophyll Color Quality Chlorophyll
Pr>F
*
NS
NS
*
NS
NS
NS
NS
NS

Rootzone (R)
Fertilizer treatment
(F)
*
*
*
*
*
*
RxF
NS
NS
NS
NS
NS
NS
Sampling date (S)
*
*
*
*
*
*
RxS
*
*
NS
*
*
NS
FxS
*
*
NS
*
*
*
RxFxS
NS
NS
NS
NS
NS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level.

50

*
NS
*
*
*
NS

*
NS
*
*
*
NS

*
NS
*
*
*
NS

Table 21. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from June to October in 2009.
Sampling date
June
July
August September October
Color
Fertilizer
treatment
Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium
¶
1xF
1xF+granular
#
2xF

†
‡
§
¶
#

‡ §

†

5.5e C
6.2cdC
6.9bC
7.5aC
7.5aC
7.5aC

6.8cA
7.6bA
8.1aA
8.2aB
8.2aB
8.2aB

6.4cB
7.2bB
7.5abB
7.7aC
7.7aC
7.7aC

6.5eB
7.8abcA
8.0abA
8.1aB
8.0aB
8.0aB

5.9eC
7.4bcB
7.7bB
8.5aA
8.5aA
8.5aA

6.1dC
5.7deC

7.4bcA
7.8abA

7.1bB
7.2bB

7.5dA
7.8bcA

7.1cdB
7.0dB

6.5bcC
7.8abA
7.3bB
7.6cdAB
7.5bB
Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

51

Table 22. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction at
four weeks after fertilizer application for each month from June to October in 2009.
Sampling date
June
July
August September October
Color
Rootzone
USGA
80-10-10
Native

†

§
‡

‡

5.9D
6.6D
6.4C

†

7.7A

6.9b§C

7.3bB

6.9C

7.7A
7.9A

7.3aC
7.4aB

7.5abB
8.0aA

7.2C
7.8AB

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

52

Table 23. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from June to October in 2009.
Sampling date
June
July
August September October
Quality
Fertilizer treatment

† ‡

†

Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium

5.5c C
6.3bC
7.1aB
7.6aC
7.6aB
7.6aB

6.6eA

6.3bB

6.2cB

5.5eC

7.6cA
8.0abA
8.2aA
7.1dC
7.1dC

7.1aB
7.6aAB
7.5aC
7.5aB
7.5aB

7.6abA
7.7aAB
7.8aB
7.3bC
7.3bC

7.3cB
7.8bA
8.4aA
8.4aA
8.4aA

1xF
1xF+granular

6.4bB
6.3bD

7.1dAB
7.8bcA

7.1aAB
7.2aB

7.3bA
7.6abA

6.7dB
6.8dC

2xF

6.1bcC

7.9abcA

7.5aB

7.7abA

7.2cB

¶

†
‡
§
¶
#

#

Turfgrass color rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

53

Table 24. Lsmean creeping bentgrass quality rating for the rootzone x sampling date interaction
at four weeks after fertilizer application for each month from June to October in 2009.
Sampling date
June
July
August September October
Quality
Rootzone
USGA
80-10-10
Native

†
§
‡

‡

6.6C
6.6B
6.2C

7.4A
7.7A
7.7A

§

†

6.9b C
7.5aA
7.2abB

7.1B

6.7cC

7.6A
7.5A

7.0bB
7.6aA

Turfgrass quality rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

54

Table 25. Lsmean chlorophyll rating for the fertilizer treatment effect of Penn ‘A-4’ creeping
bentgrass in 2009.
Chlorophyll
Fertilizer treatment
†
0.602d
Untreated control
Natural organic
0.645bc
Methylene urea
0.655ab
Urea
0.671a
Urea+phosphorous
0.676a
Urea+potassium
0.662ab
‡
0.644bc
1xF
1xF+granular
0.632c
§
0.666ab
2xF
P value
<0.01
†
‡
§

Lower case letters represent significant differences at the 0.05 probability level.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

55

There was a significant rootzone x sampling date interaction for the 2010 turfgrass color
ratings (Table 20). The USGA rootzone had the lowest turfgrass color ratings in April, May,
September, and Ocotber. However, there were no differences among rootzones for June, July,
and August (Table 27).
There was a significant fertilizer treatment x sampling date interaction for the 2010
turfgrass quality ratings (Table 20). The urea, urea+P, urea+K, and methylene urea treatments
had the highest quality ratings in April. However, in August, September, and October, the 2xF
and 1xF+granular treatments resulted in higher quality ratings than other fertilizer treatments
(Table 28). These results suggest that foliar application is more effective than granular fertilizers
for creeping bentgrass under summer stress. The reason for these results could be that root
growth is more sensitive to heat and drought stress than shoots, and root dieback would decline
bentgrass quality (Beard and Daniel, 1966; Xu and Huang, 2000).
There was a significant rootzone x sampling date interaction for the 2010 turfgrass
quality ratings (Table 20). The USGA rootzone had the lowest quality ratings for the April, June,
July, September, and October sampling dates (Table 29). The April sampling date had lower
quality ratings for the USGA and 80-10-10 rootzones (Table 29).
There was a significant fertilizer treatment x sampling date interaction for the 2010
turfgrass chlorophyll ratings (Table 20). The urea, urea+P, urea+K, and natural organic
treatments had the highest chlorophyll ratings in June (Table 30). The 2xF and 1xF+granular
treatments had the highest chlorophyll ratings in August and October. The 1xF treatment had
higher chlorophyll ratings than the urea treatment in August. The reason could be that the second
application (in the middle of the month) of 1xF was made two weeks after the urea application

56

Table 26. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date interaction at four weeks after fertilizer
application for each month from April to October in 2010.
Sampling date
April
May
June
July
August September October
†

Color
Fertilizer treatment

‡ §

Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium

6.2c B
7.1abC
7.2aB
7.5aBC
7.3aBC
7.1abC

6.0dB

6.3dB

7.2deA

6.3dB

6.0eB

8.2aA
7.0cC
7.4bC
7.4bC
7.5bB

7.9aA
7.6abA
7.3bcC
7.4bcC
7.3bcC

7.3cdC
7.4cAB
7.0efD
7.0fC
6.8fD

7.7abB
7.8aA
7.3cC
7.3cB
7.5bcB

7.7abB
7.5bcAB
7.7abB
7.8aB
7.7abB

6.1eB
7.8bAB
7.8bcA
8.2aA
8.4aA
8.4aA

1xF
1xF+granular

6.4cD
6.9bC

7.0cB
7.3bcB

7.0cB
7.6bAB

8.0bA
8.1abA

7.3cB
7.8abA

6.9dC
7.3cB

7.2dB
7.6cAB

2xF

6.7bC

7.2bcB

7.2cB

8.3aA

7.9aA

7.6bAB

7.9bA

¶

†
‡
§
¶
#

#

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

57

Table 27. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction at
four weeks after fertilizer application for each month from April to October in 2010.
Sampling date
April
May
June
July
August September October
Color
Rootzone

‡ §

USGA 6.3c C
80-10-10 6.8bB
Native
7.2aB

†

‡
§

†

7.0A

7.0bA

7.2A

7.2A

6.9B

7.2AB
7.1B

7.2aAB
7.3aB

7.3A
7.5A

7.3A
7.2B

7.4A
7.5A

7.1bA
7.3aA
7.3aB

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

58

Table 28. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date interaction at four weeks after fertilizer
application for each month from April to October in 2010.
Sampling date
April
May
June
July
August September October
†

Quality
Fertilizer treatment

‡

5.8d

6.2d

6.1d

6.1d

6.0d

5.9c

7.9aA

7.5aB

7.2cBC

7.4bcB

7.5aB

6.9cB
7.3b
7.3bAB
7.5bA

7.3abAB
7.3ab
7.4aA
7.5aA

7.3cAB
7.0c
7.1cB
7.0cB

7.5bcA
7.3c
7.3cAB
7.2cB

7.4abA
7.3b
7.5aA
7.4abA

7.4bB
7.4bA
7.3b
7.2bAB
7.3bAB

6.7cC
7.3bC

6.8cC
7.4aC

7.8bA
8.1abA

7.3cB
7.6abB

7.1cB
7.6aB

7.3bB
7.7aB

6.6cD
6.9cC
7.1bcC
8.2aA
Turfgrass color rating scale: 1-9, 1 poor, 6 acceptable, 9 best.

7.7aB

7.5aB

7.6aB

Untreated control

5.8d

Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium

6.8bC
7.0abB
7.3a
7.1aB
7.2aB

1xF
1xF+granular

6.3dD
6.6cD

¶

†
‡
§
¶
#

2xF

#

§

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

59

(at the beginning of the month), and the rating date was at the end of the month. In contrast to
color ratings, the June sampling date had the highest chlorophyll ratings. This is probably
because the TCM500 turf color meter measures light reflected from the turfgrass canopy with
sensors specific for red, green, or blue wavelengths. It then provides an NDVI (Normalized
Difference Vegetation Index), which assess whether the target being observed contains live
green vegetation or not. Therefore, in addition to color, turfgrass density may also attribute to the
rating results.

2011
There was a significant fertilizer treatment x sampling date interaction for the 2011 turfgrass
color ratings (Table 20). The urea treatments and methylene urea had the highest quality ratings
in April (Table 31). This result is similar to the color ratings in 2010. The 2xF and 1xF+granular
treatments had the highest color ratings in June and August 2011, which was different from 2010
(Table 31). The urea treatments had the highest color ratings again in October 2011. These
results show a clearer trend of granular and foliar fertilizers than previous years, that granular
fertilizer treatments had better turfgrass color in late fall and faster green up in the spring. Foliar
applications may have better turfgrass color and quality in the summer time.
There was a significant rootzone x sampling date interaction for the 2011 turfgrass color
ratings (Table 20). The native soil had the highest color ratings in April, June, and August. The
August sampling date had the highest color rating for all rootzones (Table 32).
There was a significant fertilizer treatment x sampling date interaction for the 2011
turfgrass quality ratings (Table 20). The untreated control had the lowest quality ratings below
acceptable level (<6) for all sampling dates (Table 33). All the fertilizer treatments had higher

60

Table 29. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in at four
weeks after fertilizer application for each month from April to October in 2010.
Sampling date
April
May
June
July
August September October
Quality
Rootzone

‡ §

USGA 6.3c C
80-10-10 6.8bB
Native
7.2aB
†
‡
§

†

7.0A

7.0bA

7.2bA

7.2A

6.9bB

7.2AB
7.1B

7.2aAB
7.3aB

7.3abA
7.5aA

7.3A
7.2B

7.4aA
7.5aA

7.1bA
7.3aA
7.3aB

Turfgrass quality rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

61

Table 30. Lsmean creeping bentgrass chlorophyll rating for the fertilizer treatment x sampling
date interaction at four weeks after fertilizer application for each month from June to October in
2010.
Sampling date
2010 Jun
July
2010 Aug September 2010 Oct
Chlorophyll
Fertilizer treatment
†
0.641e
0.644d
0.647d
0.666d
Untreated control 0.652e
‡

0.753aA
Natural organic
Methylene urea
0.744bA
Urea
0.752aA
Urea+phosphorous 0.753aA
Urea+potassium
0.757aA
§

1xF
1xF+granular
†
‡
§
¶

2xF

¶

0.699d
0.742bcA

0.683cB

0.672cB

0.719aA

0.691bB

0.683cB 0.683bcB 0.713abAB 0.693bB
0.664dC 0.675cBC 0.715abB 0.682cB
0.660dB 0.674cB 0.725aA 0.684cB
0.659dC 0.673cB 0.726aA 0.683bcB
0.689c 0.681abc
0.690c
0.694bB 0.696abB 0.699bcB

0.697b
0.709aB

0.711c
0.702a
0.702a
0.714ab
0.711a
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

62

quality ratings in August compared with other sampling dates. There was a significant rootzone x
sampling date interaction for the 2011 turfgrass quality ratings (Table 20). There was no
difference in quality rating among rootzones for all the sampling dates.
There was a significant fertilizer treatment x sampling date interaction for the 2011
turfgrass chlorophyll ratings (Table 20). The 2xF treatment had the highest chlorophyll ratings in
June and August. The urea and urea+K treatments had the highest chlorophyll ratings in October
(Table 35). All the fertilizer treatments had the highest chlorophyll ratings in July and September
compared with other sampling dates (Table 35).
There was a significant rootzone x sampling date interaction for the 2011 turfgrass
chlorophyll ratings (Table 20). The USGA rootzone had the lowest chlorophyll ratings in June
(Table 36). The July sampling date had the highest chlorophyll ratings for all the rootzones
(Table 36).

Within month
April 2010 and 2011
There was a significant fertilizer treatment x sampling date interaction for turfgrass color
in April (Table 37). The natural organic, methylene urea, urea, urea+P, and urea+K treatments
had the best color ratings in April 2010 (Table 38). The urea+P and urea+K treatments had the
best color ratings for April 2011. These results suggest that phosphorus and potassium addition
in urea may attribute to faster green up of bentgrass in the spring. All the fertilizer treatments had
higher April color ratings in 2010 than in 2011 (Table 38). The reason for this result could be
that the average temperature for April 2011 in Lansing was 45.3 F, compared with 52.4 F in
April 2010 (HTRC weather station).

63

Table 31. Lsmean creeping bentgrass color rating for the fertilizer treatment x sampling date interaction at four weeks after fertilizer
application for each month from April to October in 2011.
Sampling date
April
May
June
July
August September October
†

Color
Fertilizer treatment

‡ §

Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium

4.2c B
6.4aC
6.4aC
6.4aC
6.5aC
6.6aD

5.2cA

5.1cA

5.4eA

7.7bAB
7.5bAB
7.5b
7.6bAB
7.7bA

7.2bB
7.1bB
7.1bB
7.1bB
7.1bC

7.7aAB
7.6abA
7.2bc
7.2cB
7.2cB

1xF
1xF+granular

5.3bD
5.1bD

7.6bA
8.2aA

7.0bB
7.7aB

2xF

5.6bC

8.2aA

7.9aA

¶

†
‡
§
¶
#

#

5.3eA

5.1eA

6.6dC
7.0cC

7.7cdA
8.3aA

7.2dB
7.8abAB

6.5dC
7.2bcC

7.6abAB

8.2abA

7.9aA

7.5bB

4.3eB
8.0bcA 7.5bcdB
7.1cB
7.8cdA
7.3cdB
7.2bcB
7.72cdA
7.4cd
7.9aA
7.7cdA 7.5bcdAB 7.8aA
7.6dAB 7.5bcAB 7.8aA

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

64

Table 32. Lsmean creeping bentgrass color rating for the rootzone x sampling date interaction at
four weeks after fertilizer application for each month from April to October in 2011.
Sampling date
April
May
June
July
August September October
Color
Rootzone

‡ §

USGA 5.4b C
80-10-10 6.0aC
Native
6.1aC

†

‡
§

†

7.2bAB

6.6cB

6.8B

7.5bA

6.9B

7.5a
7.7aA

7.1bB
7.4aB

7.2AB
7.2B

7.4bA
7.8aA

7.3A
7.5B

6.9B
6.9B
7.2B

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

65

Table 33. Lsmean creeping bentgrass quality rating for the fertilizer treatment x sampling date
interaction at four weeks after fertilizer application for each month from April to October in
2011.
Sampling date
April
May
June
July
August September October
Quality
Fertilizer treatment

†

Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium
¶
1xF
1xF+granular
#
2xF

‡
§
¶
#

‡ §

†

4.1d C
6.4aC
6.0abC
5.7bC
5.8abD
6.2abC

4.8dB

5.1dA

5.1dA

5.2A

4.8eB

7.0cB
7.0cB
6.9cB
7.0bcC
7.2bcB

7.6aA
7.6aA
7.3abB
7.2bB
7.2bB

7.6aA
7.6aA
7.3abB
7.2bB
7.2abB

7.5A
7.5A
7.7A
7.5AB
7.4A

7.1cdB
6.8dB
7.0cdB
7.0cdC
7.2bcB

5.0dA
7.4cA
7.6bcA
7.7abcA
7.8abA
7.5bcA

4.8cC
5.8abC

6.8cB
7.6aAB

6.6cB
7.1bB

6.6cB
7.1bB

7.3A
8.1A

6.8dB
7.5aAB

7.5bcA
7.8aA

5.6bC

7.4abB

7.5abB

7.5abB

7.7A

7.4abB

7.8aA

Turfgrass color rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

66

Table 34. Lsmean creeping bentgrass quality rating for the rootozone x sampling date interaction
at four weeks after fertilizer application for each month from April to October in 2011.
Sampling date
April
May
June
July
August September October
Quality
Rootzone
USGA
80-10-10
Native

†

‡

‡

5.3C
6.2D
5.3C

†

6.8B

6.8B

6.8B

7.3A

6.6B

6.8C
7.0B

7.2B
7.0B

7.2B
7.0B

7.4A
7.2AB

6.9C
7.1B

7.2A
7.4A
7.4A

Turfgrass quality rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Capital letters indicate significant differences at the 0.05 probability level in rows.

67

Table 35. Lsmean creeping bentgrass chlorophyll rating for the fertilizer treatment x sampling
date interaction at four weeks after fertilizer application for each month from June to October in
2011.
Sampling date
June
July
August September October
Chlorophyll
Fertilizer treatment
† ‡
Untreated control 0.570f B 0.665dA 0.623dA 0.652eA 0.564eB
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium

0.667bcdB
0.660cdB
0.677abB
0.666bcdB
0.681aB

0.734aA
0.730abA
0.729abA
0.719bcA
0.715cA

0.703aA
0.694bB
0.692bAB
0.693bA
0.687bcB

0.723aA
0.719abAB
0.718abA
0.715bcA
0.709cdA

0.658bcB
0.648cC
0.666abB
0.659bcB
0.671aB

1xF
1xF+granular

0.639eC
0.656dB

0.712cA
0.710cA

0.676cB
0.693bA

0.700dA
0.705dA

0.624dC
0.652cB

§

†
‡
§
¶

2xF

¶

0.671abcB 0.723abcA 0.697abB 0.715bcA 0.655bcC
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

68

Table 36. Lsmean creeping bentgrass chlorophyll rating for the rootzone x sampling date
interaction at four weeks after fertilizer application for each month from June to October in 2011.
Sampling date
June
July
August September October
Chlorophyll
Rootzone
† ‡
USGA 0.633b B 0.714A 0.681AB 0.702A 0.628B
80-10-10 0.659abD 0.720A
Native 0.670aB 0.711A

†
‡

0.683C
0.688B

0.708B
0.709A

0.647D
0.658B

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

69

There was a significant fertilizer treatment x sampling date interaction for turfgrass
quality in April (Table 37). Granular form fertilizer treatments had the best quality ratings in
April 2010 (Table 39), which is similar to the color rating results. For April 2011, the natural
organic, methylene urea, and urea+K had the best quality ratings (Table 39). There was a
significant rootzone x sampling date interaction for April turfgrass quality rating (Table 37). The
native soil had the best quality rating in 2010, and the 80-10-10 rootzone had the best quality
rating in 2011 (Table 40).

June 2009, 2010, and 2011
There was a significant fertilizer treatment x sampling date interaction for turfgrass color
in June (Table 37). The urea, urea+P, and urea+K treatments had the highest color rating for June
2009 (Table 41). The natural organic and methylene urea treatments had the highest color ratings
in June 2010. For June 2011, the 1xF+granular and the 2xF treatments had the highest color
ratings (Table 41). These results suggest that the granular-foliar combination and foliar alone
treatments started to have better June color ratings in the third year of the research. For June
2010 and 2011, the 1xF treatment had the same color ratings with urea treatment (Table 41).
There was a significant rootzone x sampling date interaction (Table 37). The highest
turfgrass color rating was 7.4 for the native soil rootzone in June 2011 (Table 42) All the
rootzones had higher color ratings in 2010 than in 2009 and 2011 (Table 42), for the reason of a
higher June temperature in 2010 compared with 2009 and 2011.

70

Table 37. Analysis of variance for color, quality, and chlorophyll ratings of Penn ‘A-4’ creeping bentgrass in April, June, August, and
October in 2009, 2010, and 2011.
Turfgrass color, quality, and chlorophyll rating
April
Contrasts

Color Quality

June
Color

August

October

Quality Chlorophyll Color Quality Chlorophyll Color Quality Chlorophyll
Pr>F
NS
NS
*
NS
NS
NS
NS
*

Rootzone (R)
NS
NS
*
Fertilizer treatment
(F)
*
*
*
*
*
*
*
RxF
NS
NS
NS
NS
NS
NS
NS
Sampling date (S)
*
*
*
*
*
*
*
RxS
NS
*
*
*
*
NS
NS
FxS
*
*
*
*
*
*
*
RxFxS
NS
NS
NS
NS
NS
NS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

71

*
NS
*
*
*
NS

*
NS
*
*
*
NS

*
NS
*
*
*
NS

*
NS
*
*
*
NS

Table 38. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction in
April 2010 and 2011.
Sampling date
2010
2011
†
Color
Fertilizer treatment
‡ §
4.2eB
Untreated control 6.2c A
Natural organic
7.1abA
6.4bB
Methylene urea
7.2aA
6.4bB
Urea
7.5aA
6.4bB
Urea+phosphorous
7.3aA
6.5aB
Urea+potassium
7.1ab
6.6a
¶
1xF
6.4cA
5.3cdB
1xF+granular
6.9bA
5.1dB
#
2xF
6.7bcA
5.6cB
†
‡
§
¶
#

Turfgrass color rating scale: 1-9, 1 straw brown, 6 acceptable, 9 dark green.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

72

Table 39. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date interaction
in April 2010 and 2011.
sampling date
2010
2011
†
Quality
Fertilizer treatment
‡ § 4.1dB
Untreated control 5.8d A
Natural organic
6.8b
6.4a
Methylene urea
7.0aA
6.0abB
Urea
7.3aA
5.7bB
Urea+phosphorous
7.1aA
5.8bB
Urea+potassium
7.2aA
6.2aB
¶
1xF
6.2cA
4.8cB
1xF+granular
6.6bA
5.8bB
#
2xF
6.6bA
5.6bB
†
‡
§
¶
#

Turfgrass color rating scale: 1-9, 1 poor, 6 acceptable, 9 best.
Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

73

Table 40. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in April
2010 and 2011.
Sampling date
2010
2011
Quality
Rootzone
† ‡ 5.3bB
USGA 6.2c A
80-10-10 6.8bA
6.2aB
Native
7.2aA
5.3bB
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

74

There was a significant fertilizer treatment x sampling date interaction for turfgrass
quality ratings in June (Table 37). The methylene urea, urea, urea+P, and urea+K treatments had
high quality ratings consistently for the three years (Table 43). The 1xF treatment had a lower
quality rating than the urea treatment, which is different from color rating results.
There was a significant rootzone x sampling date interaction for turfgrass quality in June (Table
37). There was no difference in turfgrass quality among rootzones for all the sampling dates
(Table 44). The June 2010 sampling date had the highest quality rating for the native soil
rootzone (Table 44).
There was a significant fertilizer treatment x sampling date interaction for turfgrass
chlorophyll ratings in June (Table 37). The natural organic, urea, urea+P, and urea+K treatments
had the highest chlorophyll values for the June 2010 sampling dates. The urea+K, urea, and 2xF
treatments had the highest chlorophyll ratings in June 2011 (Table 45). For all fertilizer
treatments, the June 2010 sampling date had the highest chlorophyll ratings (Table 45). There
was a significant rootzone x sampling date interaction for June chlorophyll ratings (Table 37).
The 80-10-10 and native soil had higher chlorophyll ratings than the USGA rootzone, and June
2010 had higher chlorophyll ratings than other sampling dates (Table 46).

75

Table 41. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction in
June 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Color
Fertilizer treatment
† ‡
6.2dA
5.1cB
Untreated control 5.5e B
Natural organic
6.2cdB
7.5aA
7.2bA
Methylene urea
6.9
7.3ab
7.1b
Urea
7.5a
7.3bc
7.1b
Urea+phosphorous
7.5a
7.4bc
7.1b
Urea+potassium
7.6a
7.5bc
7.1b
§
1xF
6.1dB
6.8cA
7.0bA
1xF+granular
5.7deB
7.4bA
7.7aA
¶
2xF
6.5bcC
7.1cB
7.9aA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

76

Table 42. Lsmean bentgrass color rating for the rootzone x sampling date interaction in June
2009, 2010, and 2011.
Sampling date
2009
2010
2011
Color
Rootzone
‡
†
7.0A
6.2C
6.6c B
USGA
80-10-10
6.9
7.2
7.1b
Native
6.7B
7.3A
7.4aA
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

77

Table 43. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date interaction
in June 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Quality
Fertilizer treatment
† ‡
6.2dA
5.1dB
Untreated control 5.5c B
Natural organic
6.3b
7.5a
7.6a
Methylene urea
7.1a
7.3ab
7.6a
Urea
7.6a
7.3ab
7.3ab
Urea+phosphorous
7.5a
7.4a
7.2b
Urea+potassium
7.6a
7.5a
7.2ab
§
1xF
6.4b
6.8c
6.6c
1xF+granular
6.3bB
7.4aA
7.1bA
¶
2xF
6.1bcB 7.1bcA 7.5abA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

78

Table 44. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in June
2009, 2010, and 2011.
Sampling date
2009
2010
2011
Quality
Rootzone
USGA
6.7
7.1
6.8
80-10-10
6.6
7.2
7.3
†
7.3A
7.0A
6.2B
Native
†

Letters represent significant differences at the 0.05 probability level in rows.

79

August 2009, 2010, and 2011
There was a significant fertilizer treatment x sampling date interaction for turfgrass color
in August (Table 37). In 2009 and 2010, the urea, urea+P, and urea+K treatments had the highest
turfgrass color ratings. In 2011, the 2xF and 1xF+granular had the highest color ratings (Table
47). These results suggest that the combination and foliar treatments started to have better
turfgrass color in the third year of research. In 2009 and 2010, the 1xF had a low color rating
which was only higher than the untreated control. However, in 2011 the 1xF had a color rating
equal to the methylene urea, urea, and urea+P treatments. There was a significant rootzone effect
for the August color rating (Table 37). The native soil rootzone had the highest color rating for
all years in August (Table 48).

80

Table 45. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in June 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Chlorophyll
Fertilizer treatment
‡
†
Untreated control 0.565B 0.656e A 0.570fB
0.600C 0.759aA 0.667bcdB
Natural organic
Methylene urea
0.585C 0.742bA 0.660cdB
Urea
0.584C 0.756aA 0.677abB
Urea+phosphorous 0.584C 0.758aA 0.666bcdB
Urea+potassium
0.600C 0.758aA
0.681aB
§
1xF
0.600B 0.692dA
0.639eB
1xF+granular
0.570C 0.742bcA 0.656dB
¶
2xF
0.596C 0.718cA 0.671abcB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

81

Table 46. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
June 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Chlorophyll
Rootzone
‡
†
USGA 0.584C 0.721b A 0.633bB
80-10-10 0.597C 0.741aA 0.659abB
Native
0.577C 0.732abA 0.670aB
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

82

There was a significant fertilizer treatment x sampling date for turfgrass quality for
August ratings (Table 37). The 1xF+granular and 2xF treatments had the highest quality ratings
for August 2010 and 2011 (Table 49). These results suggest that the combination and foliar
applications are more effective than granular fertilizers for creeping bentgrass under summer
stress. For all sampling dates, fertilized treatments had better turfgrass quality than the untreated
control (Table 49).
There was a significant fertilizer treatment x sampling date interaction for turfgrass chlorophyll
ratings for the August sampling dates (Table 37). In August 2010, the 1xF, 2xF, and
1xF+granular treatments had the highest chlorophyll ratings (Table 50). In August 2011, the 2xF
and natural organic treatments had the best chlorophyll ratings (Table 50). There was a
significant rootzone x sampling date interaction for the August chlorophyll rating (Table 51). No
difference was revealed among rootzones for August for the three years. The August 2009
sampling date had the best chlorophyll rating for all the rootzones (Table 51).

October 2009, 2010 and 2011
There was a significant fertilizer treatment x sampling date interaction for turfgrass color
in October (Table 37). The urea, urea+P, and urea+K treatments had the best turfgrass color for
all the three years in October (Table 52). There was a significant rootzone x sampling date
interaction for turfgrass color in October (Table 37). The native soil rootzone had the highest
color ratings in 2009 and 2010 sampling dates (Table 53).

83

Table 47. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction in
August 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Color
Fertilizer treatment
† ‡
6.1eA
5.3eB
Untreated control 6.4c A
Natural organic
7.2bA
7.8bA
8.0bcA
Methylene urea
7.5abB 7.8bcA 7.8cdA
Urea
7.7aB
8.2aA
7.7cdB
Urea+phosphorous
7.7aB
8.4aA
7.7cdB
Urea+potassium
7.7aB
8.4aA
7.6dB
§
1xF
7.1bB
7.2dB
7.7cdA
1xF+granular
7.2bC
7.6cB
8.3aA
¶
2xF
7.3bB
7.9bA
8.2abA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

84

Table 48. Lsmean bentgrass color rating for the rootzone effect in August 2009, 2010, and 2011.
Sampling date
August
Color
Rootzone
†
7.4b
USGA
80-10-10
7.4b
Native
7.6a
P value
<0.01
†

Lower case letters represent significant differences at the 0.05 probability level.

85

Table 49. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date interaction
in August 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Quality
Fertilizer treatment
† ‡
6.1dA
5.2cB
Untreated control 6.3b A
Natural organic
7.1a
7.4bc
7.5b
Methylene urea
7.6a
7.5bc
7.5b
Urea
7.5aAB 7.3dB
7.7abA
Urea+phosphorous
7.5a
7.3c
7.5b
Urea+potassium
7.5a
7.2c
7.4b
§
1xF
7.5a
7.3c
7.3b
1xF+granular
7.5aB
7.6abB
8.1aA
¶
2xF
7.5a
7.7a
7.7ab
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

86

Table 50. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in August 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Chlorophyll
Fertilizer treatment
† ‡
0.649dB
0.623dC
Untreated control 0.682c A
Natural organic
0.706bc
0.679c
0.703a
Methylene urea
0.730ab
0.683bc
0.694b
Urea
0.746aA
0.671cC
0.692bB
Urea+phosphorous
0.746aA
0.676cB 0.693bAB
Urea+potassium
0.746aA
0.673cB
0.687bcB
§
1xF
0.707bcA 0.688abcB 0.676cB
1xF+granular
0.713bA
0.695abB 0.693bB
¶
2xF
0.744aA
0.700aB
0.697abB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

87

Table 51. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
August 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Chlorophyll
Rootzone
†
USGA 0.706A 0.671C 0.681B
80-10-10 0.724A 0.683B 0.683B
0.725A 0.685B 0.689B
Native
†

Capital case letters represent significant differences at the 0.05 probability level in columns.

88

There was a fertilizer treatment x sampling date interaction for turfgrass quality in
October (Table 37). The urea, urea+P, and urea+K treatments had the best turfgrass quality for
October 2009 (Table 54), which was similar to the October color rating results. For October
2010, the 2xF and 1xF+granular treatments had the highest quality ratings. For October 2011, the
urea, urea+P, 2xF, and 1xF+granular treatments had the best turfgrass quality (Table 54). There
was a significant rootzone x sampling date interaction for quality rating in October (Table 37).
The highest quality rating was 7.6 obtained on the native soil in October 2009. There was no
difference among rootzones on turfgrass quality for the 2010 and 2011 sampling dates (Table 55).
Results of color and quality rating from April to October suggest that different rootzone did not
play an important role in determining turfgrass color and quality when comparing the same
month for three years.
There was a significant fertilizer treatment x sampling date interaction for turfgrass
chlorophyll rating in October (Table 37). The urea, urea+P, and urea+K treatments had the best
chlorophyll rating results for October 2009 (Table 56). The 2xF and 1xF+granular treatments had
the highest chlorophyll ratings for October 2010 (Table 56). The urea, urea+K treatments had the
best chlorophyll ratings in October 2011 (Table 56). There was a significant rootzone x sampling
date interaction for October chlorophyll ratings (Table 37). No significant difference was
revealed among rootzones for chlorophyll ratings for all sampling dates (Table 57).

89

Table 52. Lsmean bentgrass color rating for the fertilizer treatment x sampling date interaction in
October 2009, 2010, and 2011.
Sampling date
October October October
2009
2010
2011
Color
Fertilizer treatment
† ‡
6.1eA
4.3eB
Untreated control 5.9e A
Natural organic
7.3bcB
7.8bA
7.1cC
Methylene urea
7.7bA 7.8bcA 7.2bcB
Urea
8.5aA
8.2aA
7.9aB
Urea+phosphorous
8.5aA
8.4aA
7.8aB
Urea+potassium
8.5aA
8.4aA
7.8aB
§
1xF
7.1cdA 7.2dA
6.5dB
1xF+granular
7.0dB
7.6cA
7.2bcB
¶
2xF
7.5bB
7.9bA
7.5bB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

90

Table 53. Lsmean bentgrass color rating for the rootzone x sampling date interaction in October
2009, 2010, and 2011.
Sampling date
2009
2010
2011
Color
Rootzone
† ‡ 7.4bA
6.9B
USGA 6.9c B
80-10-10 7.2bB
7.8aA
6.9C
Native
7.8aA
7.9aA
7.2B
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

91

Table 54. Lsmean bentgrass quality rating for the fertilizer treatment x sampling date interaction
in October 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Quality
Fertilizer treatment
† ‡
5.9cA
5.0dC
Untreated control 5.5e B
Natural organic
7.3c
7.4b
7.4c
Methylene urea
7.8bA
7.4bB 7.6bcAB
Urea
8.4aA
7.3bC 7.7abcB
Urea+phosphorous
8.5aA
7.2bC
7.8abB
Urea+potassium
8.4Aa
7.3bB
7.5bcB
§
1xF
6.7dB
7.3bA
7.5bcA
1xF+granular
6.8dB
7.7aA
7.8abA
¶
2xF
7.2cB 7.6aAB
7.8aA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

.

92

Table 55. Lsmean bentgrass quality rating for the rootzone x sampling date interaction in
October 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Quality
Rootzone
†
7.2
7.2
6.7b
USGA
80-10-10
7.0b
7.4
7.4
‡
7.3B
7.4B
7.6aA
Native
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

93

Clipping Dry Weight
There was a significant fertilizer treatment x sampling date interaction for turfgrass
clipping dry weight (Table 58). The urea treatments had consistently the highest clipping dry
weight values, except for the June 2011 sampling date, which the natural organic and methylene
urea treatments resulted in the highest clipping weight (Table 59). The untreated control had the
smallest amount of clippings for all sampling dates, along with the foliar treatments on the June
and October 2011 sampling dates (Table 59). There was a significant rootzone x sampling date
interaction for turfgrass clipping dry weight (Table 58). The native soil had the largest amount of
clipping for all sampling dates (Table 60). However, there was no important trend for rootzones
overtime.
There was a significant rootzone x fertilizer treatment interaction for turfgrass clipping
dry weight (Table 58). For the USGA rootzone, the urea, urea+P, and urea+K treatments had the
highest clipping dry weight values (Table 61). For the 80-10-10 and native soil, all the granular
fertilizer treatments (natural organic, methylene urea, urea, urea+P, and urea+K) had larger
amount of clippings than the foliar and combination treatments. For the native soil rootzone, 1xF,
2xF, and the combination treatments had statistically the same clipping dry weight with the
untreated control (Table 61). This may be explained by the fact that the native soil rootzone
provided more nutrients for the untreated control turfgrass to grow and generate top-growth.

94

Table 56. Lsmean bentgrass chlorophyll rating for the fertilizer treatment x sampling date
interaction in October 2009, 2010, and 2011.
Sampling date
2009
2010
2011
Chlorophyll
Fertilizer treatment
† ‡ 0.660dA
0.564eC
Untreated control 0.604d B
Natural organic
0.694cA
0.695bA 0.658bcB
Methylene urea
0.718bA 0.696bA 0.648cB
Urea
0.751aA
0.683cB 0.666abC
Urea+phosphorous
0.747aA
0.685cB 0.659bcC
Urea+potassium
0.743aA 0.689bcB 0.671aB
§
1xF
0.666cB
0.696bA 0.624dC
1xF+granular
0.670cB
0.706aA 0.652cC
¶
2xF
0.699bA
0.710aA 0.655bcB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

.

95

Table 57. Lsmean bentgrass chlorophyll rating for the rootzone x sampling date interaction in
October 2009, 2010, and 2011.
Sampling date
October October October
2009
2010
2011
Chlorophyll
Rootzone
†
0.683A 0.682A 0.628B
USGA
80-10-10 0.698A 0.695A 0.647B
Native
0.717A 0.697B 0.658C
†

Letters represent significant differences at the 0.05 probability level in rows.

96

Ball Roll Distance
There was a significant fertilizer treatment effect for ball roll distance in 2010 and 2011
(Table 62). The untreated control had the longest ball roll distance of 242.9 cm (Table 63), and
the natural organic treatment had the shortest ball roll distance of 221.0 cm. Organic fertilizers
increase soil microbial and fungal activities, and keep a sustainable reservoir of nutrient by its
nature of slow release fertilizer (Dorer and Peacock, 1997). However, the natural organic
treatment did not result in better turfgrass color and quality, and the 20 cm difference between
the untreated control and natural organic treatments would not raise concerns for 50% golfers
(Karcher et al., 2001). There was a significant rootzone effect for ball roll distance for 2010 and
2011 (Table 62). The USGA and 80-10-10 rootzones had longer ball roll distance than the native
soil (Table 64).

Water Infiltration Rate
There was a significant rootzone x sampling date interaction for water infiltration rate
(Table 65). In October 2010, the USGA rootzone had the highest water infiltration rate followed
with 80-10-10, and in October 2011, 80-10-10 and native soil had statistically the same low
water infiltration rate compared to the USGA rootzone (Table 66).

97

Table 58. Analysis of variance results for bentgrass clipping dry weight for 2009, 2010, and 2011.
Clipping dry
Contrasts
weight
g
Rootzone (R)
*
Fertilizer treatment
(F)
*
RxF
*
Sampling date (S)
*
RxS
*
FxS
*
RxFxS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

98

Table 59. Lsmean bentgrass clipping dry weight for the fertilizer treatment x sampling date
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
g
Fertilizer treatment
† ‡
15.9d A
Untreated control
4.8cB
4.1bB 15.7bcA 12.2bcA
Natural organic
20.5bcB 16.6aB 8.6aC
27.0aA 17.1aB
Methylene urea
26.2aA
13.4aC 8.3aD 22.6abB 13.5bcC
Urea
25.4aA
15.4aB 5.6abC 20.5bA 15.9abB
Urea+phosphorous
25.4aA
16.3aB 5.3abC 21.4abA 15.7abB
Urea+potassium
25.4aA
16.3aB 5.4abC 20.0bA 14.9abB
§
1xF
18.1cA
7.0bC 7.5abC 17.3bcA 10.7cB
1xF+granular
19.3cA
13.5aB 5.6abC 12.8cB 10.6cB
¶
2xF
23.6abA 7.5bC 5.8abC 21.3abA 13.1bcB
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

99

Table 60. Lsmean bentgrass clipping dry weight for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Clipping dry weight (g)
Rootzone
† ‡
8.8bB
2.5cC 11.1cAB 8.5cB
14.8b A
USGA
80-10-10
21.7aA
12.7aB 4.3Cb 17.5bAB 9.5bBC
Native
27.4aB
15.4aC 11.9aC 31.0aA 23.3aB
†
‡

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.

100

Table 61. Lsmean bentgrass clipping dry weight for the rootzone x fertilizer treatment interaction.
Rootzone
USGA 80-10-10
Native
g
Fertilizer treatment
† ‡
Untreated control 5.4c B
8.0cB
18.3bA
Natural organic
9.5bC
14.0abB
30.4aA
Methylene urea
9.6bC
14.4aB
26.4aA
Urea
11.5aB
16.6aB
21.6abA
Urea+phosphorous 12.2aB
15.7aB
21.3abA
Urea+potassium
11.4aB 13.3abB 22.0abA
§
1xF
6.8cB
10.5bB
19.0bA
1xF+granular
7.8bcB 12.9bAB 16.3bA
¶
2xF
9.3bB
12.8bB
20.7bA
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

101

Table 62. Analysis of variance results for bentgrass ball roll distance for 2010 and 2011.
Contrasts
Ball roll distance
cm
Rootzone (R)
*
Fertilizer treatment (F)
*
RxF
NS
Sampling date (S)
*
RxS
NS
FxS
NS
RxFxS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

102

Table 63. Lsmean bentgrass ball roll distance for the fertilizer treatment effect for 2010 and 2011.
Ball roll
distance
Contrasts
cm
Fertilizer treatment

†
‡
§

Untreated control
Natural organic
Methylene urea
Urea
Urea+phosphorous
Urea+potassium
‡
1xF
1xF+granular
§
2xF
P value

†

242.9a
221.0c
227.8b
227.9b
230.4b
229.8b
230.8b
227.0b
229.3b
<0.01

Lower case letters represent significant differences at the 0.05 probability level.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

103

Table 64. Lsmean bentgrass ball roll distance for the rootzone effect for 2010 and 2011.
Ball roll distance
cm
Rootzone
†
236.2a
USGA
80-10-10
230.3a
Native
222.5b
P value
0.01
†
Lower case letters represent significant differences at the 0.05 probability level.

104

Table 65. Analysis of variance results for water infiltration rate for October 2010 and 2011.
Contrasts
Water infiltration rate
cm/hr
Rootzone (R)
*
Fertilizer treatment (F)
NS
RxF
NS
Sampling date (S)
*
RxS
*
FxS
NS
RxFxS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

105

Table 66. Lsmean bentgrass water infiltration rate for the rootzone effect for October 2010 and
2011.
Sampling date
2010
2011
Water infiltration rate (cm/hr)
Rootzone
†
25.5a
22.3a
USGA
80-10-10
12.0b
8.1b
Native
1.5c
1.1b
†

Letters represent significant differences at the 0.05 probability level in coloum.

106

Dollar Spot Occurrence
Dollar spot occurrence was rated based on observation. Therefore results were reported
for each sampling date. There was a significant fertilizer treatment effect for dollar spot
occurrence on July 18, August 23, and September 7, 2010 (Table 67). On July 18, 2010, the
natural organic, urea+P, urea+K, 1xF+granular, and 2xF treatments had the most dollar spot
occurrence (Table 68). For the three sampling dates, the untreated control had the least dollar
spot amount compared to the fertilized treatments. Previous research has observed that natural
organic fertilizer suppresses dollar spot occurrence (Liu et al., 1995; Landchoot, 1997; Davis and
Dernoeden, 2002). However, results from this research show that natural organic fertilizer did
not reduce dollar spot occurrence. Instead of forms of fertilizer, the rates of nitrogen fertilizer
may affect dollar spot occurrence, with lower N rates decreasing dollar spot.
There was a significant rootzone effect for dollar spot occurrence on July 18, 2010 and
August 23, 2010 (Table 67). The USGA rootzone had the most dollar spot counts for
both rating dates (Table 69). Low soil moisture and low nitrogen has been reported to enhance
dollar spot severity (Vargas, 1994; Kaminski et al., 2004). The USGA rootzone, which has
relatively low moisture and nutrient retention ability, is more favorable for dollar spot activity.

107

Table 67. Analysis of variance results for dollar spot occurrence for 2010 and 2011.
Date
Contrasts
7/18/2010
8/23/2010
9/7/2010
7/6/2011
8/29/2011
Dollar spot occurance (count)
Rootzone (R)
*
NS
*
NS
NS
Fertilizer treatment
(F)
*
*
*
NS
NS
RxF
NS
NS
NS
NS
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

108

Table 68. Lsmean bentgrass dollar spot occurance for the fertilizer treatment effect.
Date
Fertilizer treatment
7/18/2010 8/23/2010
9/7/2010
Dollar spot occurance (count)
†
7.0c
10.1b
1.3c
Untreated control
Natural organic
13.2a
28.4ab
51.8a
Methylene urea
5.2b
24.2ab
50.3a
Urea
5.2b
21.5ab
43.6a
Urea+phosphorous
12.3ab
26.7ab
59.0a
Urea+potassium
8.6ab
33.0ab
59.7a
‡
3.3bc
19.8b
40.2a
1xF
1xF+granular
10.0ab
36.7ab
61.7a
§
6.5ab
41.7a
79.1a
2xF
P value
0.03
0.01
0.01
†
‡
§

Lower case letters represent significant differences at the 0.05 probability level in columns.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

109

Table 69. Lsmean bentgrass dollar spot occurance for the rootzone effect.
Date
7/18/2010
9/7/2010
Dollar spot occurance
(count)
Rootzone
†
64.5a
11.9a
USGA
80-10-10
5.0b
56.6a
Native
4.9b
30.8b
P value
0.02
0.01
†

Lower case letters represent significant differences at the 0.05 probability level in columns.

110

Worm Casting Occurrence
Worm casting occurrence was rated based on observation. Therefore, results are reported
for each sampling date. There was a significant fertilizer treatment x rootzone interaction for
worm casting occurrence for all sampling dates in 2010 and 2011 (Table 70). The USGA
rootzone had the least or no worm castings, and the native soil had the most worm casting counts
for all sampling dates in 2010 and 2011 (Tables 71-76). For the 80-10-10 rootzone, the untreated
control had the highest amount of worm castings for all sampling dates, along with the 1xF for
the September 14, 2010 and July 29, 2010 sampling dates (Tables 71-76). For the native soil, the
untreated control had the most worm castings for all sampling dates, along with natural organic
and methylene urea for the July 30, 2010 and August 6, 2011 sampling dates. These results
suggest that fertilization could reduce the severity of worm casts on the 80-10-10 and native soil
rootzones. The most worm casting mounds on the native soil among the sampling dates was
counted on August 6, 2011 (Table 75).

111

Table 70. Analysis of variance results for worm casting occurance for 2010 and 2011.
Date
Contrasts
7/30/2010
8/13/2010
9/14/2010
7/29/2011
8/6/2011
Worm casting occurance (count)
Rootzone (R)
*
*
*
*
*
Fertilizer treatment
*
*
*
*
*
(F)
RxF
*
*
*
*
*
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

112

9/2/2011
*
*
*

Table 71. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on July 30, 2010.
Rootzone
80-10Fertilizer treatment
USGA
10
Native
Worm casting (count)
‡
†
56aA
0B
35a A
Untreated control
Natural organic
3C
27bB
67aA
Methylene urea
0C
23bB
48abA
Urea
3B
20bA
36abA
Urea+phosphorous
0B
28bA
20bA
Urea+potassium
0C
9cB
20bA
§
1C
21bB
50aA
1xF
1xF+granular
2B
23bB
29abA
¶
0C
14bcB
31abA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

113

Table 72. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on August 13, 2010.
Rootzone
Fertilizer treatment
USGA
80-10-10
Native
Worm casting (count)
‡
†
107aA
0C
52a B
Untreated control
Natural organic
4B
29bB
45bcA
Methylene urea
0C
25bB
44bcA
Urea
2C
16bcB
35bcA
Urea+phosphorous
1B
23bA
18cA
Urea+potassium
0C
9cB
25cA
§
2C
32bB
81bA
1xF
1xF+granular
2B
28bA
25cA
¶
0C
17bcB
40bcA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

114

Table 73. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on September 14, 2010.
Rootzone
Fertilizer treatment
USGA
80-10-10 Native
Worm casting (count)
‡
†
1C
50a B 154aA
Untreated control
Natural organic
2C
22bB
62bcA
Methylene urea
0C
19bcB 64bcA
Urea
0C
12cB
40cA
Urea+phosphorous
0B
12cB
21dA
Urea+potassium
0B
12cB
25dA
§
1C
30abB
94bA
1xF
1xF+granular
6C
19bcB
51cA
¶
0C
15bcB
44cA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

115

Table 74. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on July 29, 2011.
Rootzone
Fertilizer treatment
USGA
80-10-10 Native
Worm casting (count)
‡
†
89aA
0B
15a B
Untreated control
Natural organic
0B
4bB
46bA
Methylene urea
0B
5bB
44bA
Urea
0B
6bB
33bcA
Urea+phosphorous
0B
10abB
26cA
Urea+potassium
0B
3bB
26cA
§
0B
7abB
33bcA
1xF
1xF+granular
0B
1bB
25cA
¶
0B
2bB
38bcA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

116

Table 75. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on August 6, 2011.
Rootzone
Fertilizer treatment
USGA
80-10-10 Native
Worm casting (count)
‡
†
223aA
0C
23a B
Untreated control
Natural organic
0C
13abcB 214abA
Methylene urea
0C
14abcB 189abA
Urea
2C
12abcB 159abcA
Urea+phosphorous
0C
19abB
66dA
Urea+potassium
1B
7bcB
95cdA
§
0C
13abcB 140bcdA
1xF
1xF+granular
0B
6cB
90cdA
¶
0B
3cB
92cdA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

117

Table 76. Lsmean bentgrass worm casting occurance for the rootzone x fertilizer treatment
interaction on September 2, 2011.
Rootzone
Fertilizer treatment
USGA
80-10-10 Native
Worm casting (count)
‡
†
173aA
1B
15a B
Untreated control
Natural organic
0B
5bcB
119bA
Methylene urea
0B
5bcB
103bcA
Urea
1B
7bcB
91cdA
Urea+phosphorous
0B
10abB
75dA
Urea+potassium
1B
4bcB
74dA
§
0B
7bcB
97cA
1xF
1xF+granular
0B
4bcB
83cdA
¶
0B
2cB
72cA
2xF
†
‡
§
¶

Lower case letters represent significant differences at the 0.05 probability level in columns.
Capital letters indicate significant differences at the 0.05 probability level in rows.
-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

118

Annual Bluegrass Invasion
There was a significant fertilizer treatment effect for Poa annua invasion (Table 77). The
natural organic treatment had the largest percentage of Poa annua invasion (Table 78). The
reason could be that the natural organic fertilizer had the largest percentage of water insoluble
nitrogen given that all the granular fertilizers were applied at the same rate. Therefore, the
natural organic treatment provides a more consistent nutrient reservoir favoring Poa annua
invasion. The untreated control, urea, urea+P, and urea+K treatments had the smallest amount of
annual bluegrass invasion. This result is in contrast to Hardt and Schulz (1995)’s conclusion that
Ureaform-fertilized bentgrass was more susceptible to annual bluegrass invasion than IBDU,
natural organic N (horn meal), and mineral N (ammonium nitrate) applications at the rate of 20,
-2

-1

40 or 80 g m year .

119

Table 77. Analysis of variance results for annual bluegrass invasion on May 20, 2011.
Poa invasion
Contrasts
%
Rootzone (R)
NS
Fertilizer treatment (F)
*
RxF
NS
*, and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

120

Table 78. Lsmean annual bluegrass invasion for the fertilizer treatment effect on May 20, 2011.
Date
May 20, 2011
Poa
Fertilizer treatment
invasion %
†
3.4d
Untreated control
Natural organic
19.8a
Methylene urea
8.5b
Urea
3.1d
Urea+phosphorous
3.1d
Urea+potassium
3.8d
‡
6.5bc
1xF
1xF+granular
4.6cd
§
7.4bc
2xF
P value
<0.01
†
Lower case letters represent significant differences at the 0.05 probability level.
‡
§

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

121

CONCLUSIONS
The native soil rootzone had the highest soil nitrogen, phosphorous, and potassium
concentration compared with the 80-10-10 and USGA rootzones. The granular fertilizers (natural
organic, methylene urea, urea, urea+K, and urea+P) tend to have higher soil nitrate nitrogen
concentration than the foliar and combination treatments (1xF, 2xF, and 1xF+granular). The
urea+P treatment did not result in a higher soil P content, and the untreated control did not result
in lower soil P concentration than other fertilizer treatments on any of the rootzones. The urea+K
treatment did not result in a higher soil K content. In addition, a high soil K concentration for the
untreated control was observed, indicating less turfgrass growth for the untreated control, thereby
less tissue K absorption from the soil.
In contrast to the soil N, P, and K analysis, tissue N, P, and K analysis revealed that the
native soil rootzone had the lowest tissue N, P, and K concentration compared with the 80-10-10
and USGA rootzones. Tissue total N and P values for the native rootzone are under the turfgrass
common sufficiency range of 2.8-3.5% and 0.2-0.5% (Carrow et al. 2001), respectively, for the
October 2010, June 2011, and October 2011 sampling dates. These results suggest that soil
nitrogen, phosphorous, and potassium test results could not reflect nitrogen, phosphorous, and
potassium nutrient status in turfgrass tissue. Tissue analysis may need to be considered when
assessing nutrient status and making recommendations.
The urea+P and 2xF treatments maintained high tissue P concentration on both October
2010 and October 2011 sampling dates, suggesting that the 2xF treatment may have similar
effects in improving tissue P content as P supplement in the Urea+P fertilizer treatment. K
supplement in the urea+K treatment is effective in improving turfgrass tissue K across rootzones

122

overtime. Contrary to soil K result as previously discussed, the untreated control had the lowest
tissue K values across all sampling dates.
For the first year of fertilizer application in 2009, the urea treatment had the best turf
color and quality for all sampling dates. The double-rate foliar treatment was as effective as the
slow-release fertilizer treatments (natural organic and methylene urea) for turfgrass color and
quality in 2009. The combination and single-rate foliar treatments had the lowest turfgrass color
ratings among fertilized treatments in 2009. For 2010 and 2011 sampling dates, the granular
fertilizer treatments (natural organic, methylene urea, and urea) had better turfgrass color and
quality in the late fall and faster green up speed in the spring. Foliar applications result in better
turfgrass color and quality for the August sampling date, when creeping bentgrass is under
summer stress. Root growth is limited and is more sensitive to heat and drought stress than
shoots. In August 2010, the 1xF treatment had higher chlorophyll ratings than the urea treatment,
suggesting that foliar application at half rate could be more effective in maintaining turfgrass
color than the full rate urea treatment when bentgrass is under summer stress in August. The
USGA rootzone usually has lower color and quality ratings in April and June sampling dates
compared with the 80-10-10 and native soil rootzones.
The natural organic treatment had the shortest ball roll distance of 221.0 cm, yet it did not
result in better turfgrass color and quality, and the 20 cm difference between the untreated
control and natural organic treatments would not raise concerns for golf players. The natural
organic treatment had the largest percentage of annual bluegrass invasion, which is contrary to
Hardt and Schulz (1995)’s conclusion that Ureaform-fertilized bentgrass was more susceptible to
annual bluegrass invasion than IBDU, natural organic N (horn meal), and mineral N (ammonium
-2

-1

nitrate) applications at the rate of 20, 40 or 80 g m year . The natural organic fertilizer did not

123

reduce dollar spot occurrence, which is contrary to some literature articles (Liu et al. 1995,
Landchoot 1997, Davis and Dernoeden 2002). Additionally, instead of forms of fertilizer, the
rates of nitrogen fertilizer may affect dollar spot occurrence, with lower rate decreasing dollar
spot. The USGA rootzone had the most dollar spot counts, because of its relatively low moisture
and nutrient retention ability, which is more favorable for dollar spot activity.

124

APPENDIX

125

Table A1. Analysis of variance for soil calcium (Ca) and magnesium (Mg) of Penn ‘A-4’
creeping bentgrass in 2009, 2010, and 2011.
Soil nutrient test
Ca
Mg
Contrasts
Pr>F
Rootzone (R)
*
*
Fertilizer treatment (F)
NS
NS
RxF
NS
NS
Sampling date (S)
*
*
RxS
*
*
FxS
NS
NS
RxFxS
NS
NS
* and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

126

Table A2. Lsmean bentgrass soil calcium (Ca) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Soil Ca (ppm)
Rootzone
USGA
1062.33
1016.63
1163.33
1277.85
1152.78
80-10-10
1093.48
1169.67
1118.93
1394.59
1259.26
Native
1421.95
1360.89
1436.26
1639.63
1533.81

127

Table A3. Lsmean bentgrass soil magnesium (Mg) for the rootzone x sampling date interaction.
Sampling date
October
October
October
2009
June 2010
2010
June 2011
2011
Soil Mg (ppm)
Rootzone
USGA
84.04
88.29
116.22
99.48
95.18
80-10-10
99.33
103.37
124.67
104.52
89.29
Native
219.24
218.33
241.48
233.44
237.74

128

Table A4. Analysis of variance for tissue nutrients of Penn ‘A-4’ creeping bentgrass in 2009, 2010, and 2011.
Tissue nutrient test
Contrasts
Ca
Mg
S
Fe
Mn
Zn
Cu
B
Pr>F
Rootzone (R)
NS
NS
*
*
*
NS
*
*
Fertilizer treatment (F)
*
*
*
*
*
*
*
*
RxF
NS
NS
NS
NS
NS
NS
NS
NS
Sampling date (S)
*
*
*
*
*
*
*
*
RxS
*
*
*
*
*
*
*
*
FxS
*
*
*
*
*
*
*
*
RxFxS
NS
NS
NS
NS
NS
NS
NS
NS
* and NS indicate significance at P=0.05, and not significant at P=0.05 level, respectively.

129

Al

Na

*
*
NS
*
*
*
NS

NS
NS
NS
*
NS
NS
NS

Table A5. Lsmean creeping bentgrass tissue calcium (Ca) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Ca (%)
Untreated control
2.36
1.12
2.25
3.08
2.68
Natural organic
1.96
1.14
1.67
1.61
1.60
Methylene urea
1.58
1.31
1.71
1.89
1.22
Urea
1.65
1.84
1.36
1.74
1.16
Urea+phosphorous
1.65
1.85
1.44
1.72
1.17
Urea+potassium
1.65
1.66
1.27
1.56
1.05
†
1.81
1.17
2.00
1.76
1.72
1xF
1xF+granular
1.89
1.25
1.81
1.65
1.35
‡
1.69
1.17
1.61
1.59
1.13
2xF
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

130

Table A6. Lsmean bentgrass tissue calcium (Ca) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Rootzone
Tissue Ca (%)
USGA
2.22
1.40
1.13
1.82
1.34
80-10-10
1.81
1.41
1.86
1.72
1.36
Native
1.50
1.36
2.03
2.00
1.67

131

Table A7. Lsmean creeping bentgrass tissue magnesium (Mg) for the rootzone x fertilizer
treatment interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Mg (%)
Untreated control
0.61
0.34
0.62
0.81
0.67
Natural organic
0.50
0.39
0.47
0.52
0.41
Methylene urea
0.43
0.36
0.48
0.57
0.34
Urea
0.44
0.44
0.39
0.54
0.32
Urea+phosphorous
0.44
0.45
0.43
0.53
0.33
Urea+potassium
0.44
0.42
0.38
0.49
0.30
†
1xF
0.48
0.35
0.54
0.53
0.47
1xF+granular
0.51
0.35
0.47
0.52
0.37
‡
2xF
0.45
0.33
0.46
0.52
0.31
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

132

Table A8. Lsmean bentgrass tissue magnesium (Mg) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Mg (%)
Rootzone
USGA
0.55
0.38
0.33
0.55
0.36
80-10-10
0.50
0.39
0.53
0.54
0.38
Native
0.42
0.37
0.56
0.59
0.44

133

Table A9. Lsmean creeping bentgrass tissue sulfur (S) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue S (%)
Untreated control
0.35
0.56
0.21
0.27
0.25
Natural organic
0.36
0.55
0.26
0.47
0.29
Methylene urea
0.37
0.51
0.27
0.45
0.33
Urea
0.36
0.44
0.29
0.46
0.33
Urea+phosphorous
0.36
0.42
0.29
0.44
0.32
Urea+potassium
0.36
0.44
0.37
0.68
0.35
†
1xF
0.37
0.55
0.20
0.42
0.29
1xF+granular
0.37
0.49
0.24
0.46
0.31
‡
2xF
0.36
0.52
0.28
0.47
0.33
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

134

Table A10. Lsmean bentgrass tissue sulfur (S) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue S (%)
Rootzone
USGA
0.36
0.48
0.34
0.53
0.38
80-10-10
0.37
0.52
0.29
0.51
0.36
Native
0.35
0.50
0.17
0.33
0.20

135

Table A11. Lsmean creeping bentgrass tissue iron (Fe) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Fe (%)
Untreated control 3380.33 1689.11 8379.89 5521.11 4228.89
Natural organic
2903.22 1674.33 5995.11 2939.67 2379.56
Methylene urea
2281.44 2418.33 5253.56 2863.89 1750.11
Urea
2420.11 4008.67 4666.56 2617.33 1747.11
Urea+phosphorous 2420.11 3375.78 5326.33 2645.56 2064.00
Urea+potassium
2420.11 3240.33 3868.44 2071.11 1861.22
†
1xF
2546.67 1740.11 7362.22 3431.89 2742.00
1xF+granular
2751.44 2330.00 6564.78 2589.67 2507.89
‡
2xF
2511.67 1573.33 4861.44 2708.56 1840.89
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

136

Table A12. Lsmean bentgrass tissue iron (Fe) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Fe (%)
Rootzone
USGA
2498.29 2409.48 2727.70 2066.56 1512.81
80-10-10 2597.00 2455.63 6118.11 2285.56 1775.81
Native
2959.67 2484.89 8580.30 4777.48 3751.93

137

Table A13. Lsmean creeping bentgrass tissue manganese (Mn) for the rootzone x fertilizer
treatment interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Mn (%)
Untreated control
86.56
88.00
108.22
105.44
99.11
Natural organic
79.78
80.00
85.89
72.89
60.44
Methylene urea
69.56
75.11
80.11
73.00
50.22
Urea
68.44
88.11
70.44
70.44
49.89
Urea+phosphorous
68.44
87.33
75.89
70.56
54.44
Urea+potassium
68.44
85.44
69.78
70.89
51.33
†
1xF
74.44
84.89
99.22
80.00
65.67
1xF+granular
79.11
82.89
90.33
73.33
61.22
‡
2xF
70.33
77.00
81.56
69.78
50.78
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

138

Table A14. Lsmean bentgrass tissue magnesium (Mn) for the rootzone x sampling date
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Mn (%)
Rootzone
USGA
70.76
78.67
53.70
59.81
49.04
80-10-10
77.10
80.48
84.22
65.70
48.70
Native
78.52
90.44
115.89
103.26
83.30

139

Table A15. Lsmean creeping bentgrass tissue zinc (Zn) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Zn (%)
Untreated control
30.67
61.78
52.00
29.22
41.11
Natural organic
33.67
73.33
49.78
44.00
40.00
Methylene urea
34.33
66.78
49.11
41.33
36.44
Urea
32.56
74.00
46.78
40.22
39.00
Urea+phosphorous
35.44
79.22
48.11
39.00
37.33
Urea+potassium
34.56
72.00
44.56
40.44
35.89
†
1xF
33.56
68.33
49.78
40.78
39.56
1xF+granular
36.67
68.67
50.44
46.89
41.11
‡
2xF
35.44
66.44
53.11
43.67
43.11
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

140

Table A16. Lsmean bentgrass tissue zinc (Zn) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Zn (%)
Rootzone
USGA
32.70
72.59
42.96
49.41
38.56
80-10-10
34.63
72.11
50.81
41.81
37.44
Native
34.96
65.48
54.11
30.63
41.85

141

Table A17. Lsmean creeping bentgrass tissue copper (Cu) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Cu (%)
Untreated control
9.89
27.00
83.89
13.67
89.00
Natural organic
11.00
29.67
62.11
16.00
53.44
Methylene urea
11.11
38.56
56.22
14.78
42.00
Urea
10.56
59.56
49.22
15.22
46.56
Urea+phosphorous
10.56
50.89
61.11
14.11
44.22
Urea+potassium
10.56
51.11
44.22
14.33
39.67
†
1xF
11.33
29.11
75.33
17.78
58.00
1xF+granular
11.89
34.11
67.67
18.44
51.78
‡
2xF
12.33
28.00
52.11
21.00
45.89
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

142

Table A18. Lsmean bentgrass tissue copper (Cu) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Cu (%)
Rootzone
USGA
10.10
27.23
33.04
18.11
32.67
80-10-10
11.71
29.66
63.33
16.41
37.30
Native
11.67
34.74
87.59
13.93
86.89

143

Table A19. Lsmean creeping bentgrass tissue boron (B) for the rootzone x fertilizer treatment
interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue B (%)
Untreated control
4.78
9.56
6.89
4.89
2.00
Natural organic
4.78
8.67
6.11
5.33
2.00
Methylene urea
4.78
8.56
5.78
5.33
2.56
Urea
4.67
8.33
6.56
5.67
2.44
Urea+phosphorous
4.67
7.78
5.67
5.33
2.56
Urea+potassium
4.67
9.11
5.00
6.44
2.11
†
1xF
4.56
9.33
7.44
6.00
2.67
1xF+granular
5.22
9.11
6.56
6.67
2.33
‡
2xF
4.33
9.44
6.00
5.89
2.56
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

144

Table A 20. Lsmean bentgrass tissue boron (B) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue B (%)
Rootzone
USGA
5.05
9.26
5.56
6.52
3.22
80-10-10
4.71
8.30
6.52
5.96
2.44
Native
4.43
9.07
6.59
4.70
1.41

145

Table A21. Lsmean creeping bentgrass tissue aluminum (Al) for the rootzone x fertilizer
treatment interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Fertilizer treatment
Tissue Al (%)
Untreated control
550.89
496.78 3018.78 961.00 2486.11
Natural organic
522.89
588.44 2270.44 683.11 1478.78
Methylene urea
431.67
929.00 2025.67 638.33 1148.78
Urea
439.89 1593.11 1705.56 560.67 1206.22
Urea+phosphorous 399.33 1396.33 1824.11 544.11 1126.33
Urea+potassium
403.44 1424.11 1483.33 467.00
988.56
†
1xF
476.00
556.67 2719.89 666.89 1539.56
1xF+granular
473.00
804.22 2377.56 552.89 1276.22
‡
2xF
398.33
505.44 1818.00 503.11 1080.22
†
‡

-1

Gary's Green foliar fertilizer treatment at the rate of 6.1 kg N ha per application.
-1

Gary's Green foliar fertilizer treatment at the rate of 12.2 kg N ha per application.

146

Table A22. Lsmean bentgrass tissue aluminum (Al) for the rootzone x sampling date interaction.
Sampling date
October
June
October
June
October
2009
2010
2010
2011
2011
Tissue Al (%)
Rootzone
USGA
326.85
851.07
847.52
301.89
713.22
80-10-10 425.56
892.15 2030.89 408.81
854.37
Native
612.74 1021.48 3536.04 1148.33 2542.67

147

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148

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