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THE EFFECTS OF TURVES WITHIN A REF INED WOOD FIBER MAT (ECOMAT®)
OVER PLASTIC

By

John Charles Sorochan

A THESIS

Submitted to
Michigan State University
In partial fulfillment of the requirements
For the degree of

MASTER OF SCIENCE

Department of Crop and Soil Sciences

1999

ABSTRACT

THE EFFECTS OF TURVES WITHIN A REFINED woon FIBER MAT
(ECOMATO) OVER PLASTIC
By

John Charles Sorochan

Establishing sod within a refined wood fiber mat (Ecomat®) over plastic was
investigated at the Hancock Turfgrass Research Center, East Lansing, MI. in 1995 and
1996. Three major areas of investigation included mulching, growth media comparison,
and seeding and fertilizer applications. In addition, the establishment of four different
turfgrass species was investigated. These turf species included Kentucky bluegrass (Poa
pratensis L.), Supina bluegrass (P. supina Schreb.), perennial ryegrass (Lolium perenne
L.), and tall fescue (F estuca amndinacea Schreb.). The objectives of the research was:

1) To determine the effect of different mulch types for aiding turfgrass
establishment within Ecomat®.

2) To compare different growth media for sod production on plastic, as
well as their effectiveness as an established turf for athletic field use.

3) To determine optimum seeding and fertilizer rates for turfgrass
establishment within Ecomat® over plastic.

In the first experiment, mulching with straw, PennMulchm, and hydromulch,
respectively increased turf cover (significantly) versus the other four mulches (fine grade

compost, crumb rubber, native soil, and GerminatorQ) and the control (no mulch). In

addition, perennial ryegrass established a greater turf cover than Supina bluegrass. In the
second experiment, SportGrassm had significantly greater turfgrass cover then the
Ecomat®, pine wood mulch and sand growth media. In the third experiment, increasing
the seeding rate for four-turf species studied significantly increased turf cover. The use
of an organic source of nitrogen (Milorganite®) established denser Kentucky bluegrass
turf than ammonium nitrate. Additionally, as the rate of nitrogen increased (g N m'z) so
did turf density. In conclusion, establishing sod within EcomataD over plastic is plausible.
However, the high maintenance demanded deems large-scale sod production utilizing the
Ecomat® potentially cost ineffective. This is apparent as a result of the watering

problems encountered in Chapters 2 and 3.

Copyright by
JOHN CHARLES SOROCHAN
1999

DEDICATED

To my mom and dad

Shirley Jones and Sam Sorochan

ACKNOWLEDGEMENTS

I would like to extend my deepest recognition to Dr. John (Trey) N. Rogers, 1H,
for his guidance, support, and most importantly friendship. Thank you for the profusion
of experiences presented to me during my graduate student experience. Your belief in
my abilities has been a huge influence towards obtaining my goals. My graduate
committee also deserves special recognition for their guidance and insight throughout my
graduate experience. Thank you to Drs. Jim R. Crum, Paul E. Rieke, and Joe M. Vargas.
It was an honor to have collaborated with each of you. I am thankful to my good friend
Doug Karcher, who helped to make a computer illiterate person somewhat literate.
Thanks to John Stier for his inspiration and encouragement to continue on with my
education. Special thanks must be extended to Mark Collins for his tolerance and help,
Thom Nikolai for his friendship and for his lessons about turf that books don’t teach, and
to all other graduate students and student workers with whom I interacted. Finally, I
would like to thank the Michigan Turfgrass Foundation and Michigan State University

for their financial assistance and support.

vi

TABLE OF CONTENTS

LIST OF TABLES
LIST OF FIGURES
INTRODUCTION

CHAPTER 1
THE EFFECT OF MULCH TYPE ON TURFGRASS ESTABLISHMENT ON
PLASTIC

Abstract

Introduction

Materials and Methods

Results

Discussion

CHAPTER 2
THE EFFECT OF DIFFERENT GROWTH MEDIA FOR TURFGRASS
ESTABLISHMENT AND PERFORMANCE
Abstract
Introduction
Materials and Methods
Results
Experiment one — Turfgrass establishment
Experiment two — Turfgrass performance
Discussion
Experiment one — Turfgrass establishment
Experiment two — Turfgrass performance

CHAPTER 3
THE EFFECT OF SEEDING RATE AND FERTILIZER SOURCE AND
RATE ON TURFGRASS ESTABLISHMENT ON PLATIC
Abstract
Introduction
Materials and Methods
Results
Experiment one — Seeding study
Experiment two - Fertility study

vii

ix

HHOQU’IM

\IO

19
19
21
24
27
27
29
34
34
34

36
36
37
4O
43
43
45

Discussion
Experiment one — Seeding study
Experiment two - Fertility study

CONCLUSIONS
Chapter 1 - Mulching study
Chapter 2 — Turfgrass establishment and performance
Chapter 3 — Turfgrass seeding and fertility studies

LIST OF REFERENCES

viii

48
48
48

50
50
50
51

52

LIST OF TABLES

Table 1 — Significance of treatment effects for turfgrass cover in Ecomat® mulching
study, East Lansing, MI. 1995-96 ................................................................. 12

Table 2 — Turf species by mulch type interactions 28 days afier seeding averaged
over four seeding dates, East Lansing, MI ...................................................... 12

Table 3 - Mulch type by season interaction 28 days after seeding averaged over
turfgrass species, East Lansing, MI. 1995-96 .................................................. 14

Table 4 - Turf species by season interaction 28 days after seeding averaged over all
mulch types and the control, East Lansing, MI. 1995-96 .................................... 16

Table 5 -— Part one: Turfgrass establishment — Significance of treatment effects for
turfgrass cover, East Lansing, MI. 1996 ........................................................ 28

Table 6 — Part one: Turfgrass establishment — Turfgrass density (0-100%) for turfgrass
species and growth media established as sod on plastic, East Lansing, MI. 1996 ........ 28

Table 7 - Part two: Turfgrass performance — Effect of traffic on turf color of supina
bluegrass grown on different growth media with crumb rubber topdressing as a split,
East Lansing, MI. 1996-97 ........................................................................ 30

Table 8 — Part two: Turfgrass performance — Effect of traffic on turf density of supina
bluegrass grown on various growth media with crumb rubber topdressing as a split,
East Lansing, MI. 1996-97 ........................................................................ 30

Table 9 — Part two: Turfgrass performance — Effect of traffic on turf quality of supina
bluegrass grown on various growth media with crumb rubber topdressing as a split,
East Lansing, MI. 1996-97 ........................................................................ 31

Table 10 - Part two: Turfgrass performance — Effect of traffic on clipping yields of
supina bluegrass grown on various growth media (GM) with crumb rubber (CR)
topdressing as a split, East Lansing, MI. 1996-96 ............................................. 31

Table 11 - Part two: Turfgrass performance - Effect of surface hardness and shear
strength on Poa supina grown on varying growth media with crumb rubber
topdressing as a split, East Lansing, MI. 1997 ................................................. 33

Table 12 —- Seeding rates (g m’z) for turfgrass establishment on four turf species,
East Lansing, MI. 1997 ........................................................................... 40

Table 13 — Fertilizer treatment types and rates for Poa pratensis establishment within
Ecomat® over plastic, East Lansing, MI. 1997 ................................................ 42

Table 14 — Seeding study — Effect of three seeding rates on turfgrass density for four
turfgrass species utilizing Ecomat® on plastic, East Lansing, MI. 1997 ................... 44

Table 15 - Fertility study — Effect of fertilizer type and rate on turfgrass density for
establishing Poa pratensis within Ecomat® over plastic, East Lansing, MI. 1997 ....... 46

Table 16 — Fertility study — Effect of increasing post phosphorous and potassium
rates, or using urea nitrogen on turfgrass density for establishing Poa pratensis within
Ecomat® over plastic, East Lansing, MI. 1997 .............................................. 47

LIST OF FIGURES

Figure l — Daily high and low temperatures (0C) 28 days after seeding (DAS) for
3 July 1995 (A), 29 September 1995 (B), 5 July 1996 (C), and October 1996 (D)
seeding dates ....................................................................................... 11

xi

INTRODUCTION

High quality turfgrass stands on athletic fields and golf courses are in greater
demand than ever before. Not only does the quality of the turf have to be acceptable, but
also there is a growing demand to provide a turf stand for immediate playability. High
quality turf that immediately readies for athletic play encompasses a dense wear resistant
turf that provides a uniform and stable playing surface.

The rate of establishment is important for determining a satisfactory turf field.
Conventional sodding provides instant turfgrass cover, but the newly sodded area will
only be ready for play once the sheared roots have regenerated, which may take as long
as 2 months.

Literature describing sodding practices date as far back as 1159, to the first
Japanese book on gardening entitled, “Aatu-tei-kai” (Beard, 1992). Modern sod
production began with the use of mechanical operations, where turfgrass cutting
machines allowed easier and more accurate sod harvesting than manual harvesting
(Beard, 1992). Conventional sod harvesting limits the stability of the turfgrass stand until
the sheared roots have been regenerated. The lack of a dense or deep root structure
decreases nutrient and water uptake for the turfgrass plants, leading to a lower quality
turfgrass stand (Decker, 1991b). This may be particularly evident if sod is harvested
during sub-optimal growing conditions such as hot and dry summers. In addition, soil
layering can be a problem when using conventional sod. Root growth is severely limited
with sod grown on a soil of finer texture than the root zone mix it is intended to cover,

and the sod layering (finer textured soil over coarser textured soil) could be a problem in

the future as macro pore space decreases. Although instant cover is provided, the turf is
not immediately playable.

The shortcoming of conventional sodding practices can be avoided when turf is
grown on non-soil media, over an impervious surface such as plastic. Some advantages
of growing sod on plastic include the elimination of soil layering by selecting a specific
growth medium, the elimination of root shearing during harvest, and producing a sod
more rapidly in time for harvesting. This enables the sod to establish more quickly on the
intended site (Decker, 1991b and Decker, 1975). The presence of the intact root system
enables the newly laid sod to be fully established in a period much shorter than
conventional sodding methods (Cairol and Chevallier, 1981). The sod produced is
lightweight due to the absence of soil, allowing for cheaper shipping costs and larger sod
pieces (Decker, 199la). Sod pieces are held together by the binding of the roots and the
grth media selected, making the sod very strong and easy to handle. This strength
enables the production of turfgrasses with a bunch type growth habit. Typically,
turfgrasses with a bunch type growth habit germinate and establish more rapidly than
turves with a rhizomatous or stoloniferous growth habit allowing for an even more rapid
sod to be produced. Traditional sod consists of turfgrasses with rhizomatous or
stoloniferous growth habits only.

An immediately playable turf stand provided by sod grown on plastic is very
beneficial to turf managers. For instance, a soccer field manager could replace the worn
turf in a soccer goal area between games (Cairol and Chevallier, 1981), perhaps as

frequently as once per week.

Commercially, sod grown on plastic uses either wood mulch, compost or sand as
the growth medium. A refined wood fiber mat (Ecomat®) is an erosion control mat
produced by Canadian Forest Products Ltd. in New Westminster, British Columbia and
has the potential to be an effective growth medium. It will be placed over top of the
plastic. Previous research has shown the use of an organic fiber medium can produce a
sod when grown over plastic (Hensler et al., 1996). Selecting a refined wood fiber mat as
the growth media adds many benefits to establishing sod on plastic. For instance, the
refined wood fiber mat (Ecomat®), which is made from a blend of residual wood fibers,
provides an adequate seedbed without the use of soil. An adequate seedbed consists of a
smooth and uniform surface for seeding. In addition, the mat layer has the ability to
provide flexible support for the turfgrass during and after establishment. Used as an
erosion control mat, the refined wood fiber is available in large rolls (1.2 m by 41 m).
This makes it possible to establish large pieces of sod that are more light weight then
conventional pieces of sod of the same size.

While there are many advantages to using sod produced on plastic over
conventional sod, further research is warranted, particularly with the use of the refined
wood fiber mat as a growth medium. Unlike conventional sod production, producing sod
on plastic using a non-soil growth medium, like the refined wood fiber mat, presents
many problems. For instance, water holding capacity is low, seeding and fertilizer
recommendations have not been determined, and the actual plausibility of using the wood
fiber mat as a grth medium also needs to be determined. As a result three main
objectives exist to test the use of the refined wood fiber mat as a growth medium for sod

production on plastic. The three main objectives are:

1)

2)

3)

To determine the effect of different mulch types for aiding turfgrass

establishment using a refined wood fiber mat (Ecomat®).

To compare different growth media for sod production on plastic, as
well as their effectiveness as an established turf for athletic field use.
To determine optimum seeding and fertilizer rates for turfgrass

establishment on plastic using the refined wood fiber mat (Ecomat®).

Chapter 1

THE EFFECT OF MULCH TYPE ON TURFGRASS ESTABLISHMENT 0N
PLASTIC ‘

ABSTRACT

The germination and establishment of Lolium perenne (bunch type) and Poa
supina (stoloniferous) within a refined wood fiber mat (Ecomat®) placed on plastic
sheeting was evaluated using seven mulches and a control with no mulch. Percent
turfgrass cover (0-100%) as a measure of germination density was evaluated at 7, 14, 21,
and 28 days after seeding. The study began on 3 July 1995 and was repeated on 29
September 1995, 5 July 1996, and 1 October 1996. The four seeding dates were chosen
to show the effects of mulches under optimal and sub-optimal growing conditions for
cool season turfgrasses. The seven mulches consisted of hydrated fiber mulch,
copolymer of sodium acrylarnide, crumb rubber, straw, fine grade compost, pelletized
fiber mulch, and a native clay loam soil. Two turfgrass species difi‘ered significantly
among the seven mulch treatments and the control, and the four seeding dates. Lolium
perenne achieved slightly higher turfgrass cover than Poa supina on two dates tested.
The straw, pelletized fiber mulch, and hydrated fiber mulch resulted in the greatest
turfgrass cover regardless of seeding date. However, crumb rubber performed equally
well only during the 29 September 1995 seeding trial. In summary, the use of a particular
mulching material (straw, pellet mulch, and hydro mulch) will enhance turfgrass density
during seed germination; with the benefits of these mulches increasing with increasing

seed germination times.

INTRODUCTION

Conventional sod production is restricted to turfgrasses with a stoloniferous
and/or rhizomatous growth habit because the rhizomes and stolons provide cohesiveness
for the sod, even after the roots are sheared during harvest. Bunch type grasses have
many practical uses in a turfgrass setting; for e.g., F estuca arundinacea (tall fescue) is an
excellent grass for dry shady conditions, and could be produced if the roots remained
intact during sod harvesting. Recent experiments at Michigan State University have
shown that growing sod on plastic using a refined wood fiber mat (Ecomat®) allows
harvesting of bunch type sods without root shearing (unpublished data). Establishing sod
over an impervious layer like plastic and within a soil-less growing medium (Ecomat®)
will eliminate root shearing during harvest. This enables the intact roots to provide the
necessary strength for turfgrasses with a bunch type growth habit to be grown as sod.
Therefore, growing sod in Ecomat® allows for a greater variety of turfgrass species to be
grown.

Ecomat® alone does not provide constant enough conditions for seed germination,
and in the absence of soil, water and nutrient availability is reduced. Mulching is one
way to correct this problem, but the relative effectiveness of various mulching materials
is not known.

Any lifeless material can be used as a mulch (Turgeon, 1991). For over 100 years
it has been known that mulching is one way to preserve a uniform degree of moisture
(Saunders, 1866) because it reduces the rate of evaporation from the soil surface
(W arington, 1900). Mulches can also increase or decrease surface temperatures during

adverse growing conditions (Wooding and Sparrow, 1979), reduce potential seed loss to

runoff and Splashing caused by rain or irrigation, and greatly reduce wind erosion (Beard,
1973). In the turfgrass industry, most research on mulches has concentrated on
prevention of seed and soil erosion. The potential of mulches for aiding germination and
turf establishment, particularly on a soil-less growing medium like Ecomat®, has yet to be
investigated.

Many types of mulching materials are available; selection of a given type is based
on its availability, cost, ease of application, potential for preventing weeds, effectiveness
in erosion control, and the microenvironment it provides for seed germination (Beard,
1973). The unique physical characteristics of each mulch type determine how they
perform for turfgrass establishment. For instance, the color and water holding capacity of
the mulch may determine the time of year when a particular mulch is most effective;
during adverse growing conditions (e. g., mid-summer heat and drought) a particular
mulch may exacerbate the already unfavorable growing conditions (Dudek et al., 1966).
Therefore, it is important to compare mulch types that may differ in effectiveness under
various environmental conditions.

Seven mulches were chosen for comparison: hydrated fiber mulch, copolymer 'of
sodium acrylate and acrylamide, crumb rubber, straw, fine grade compost, pelletized
fiber mulch, and a native clay loam soil. The copolymer of sodium acrylate and
acrylamide serves as a sticking agent intended to maintain moisture levels and prevent
erosion. Straw is a traditional mulch that allows good air movement and is relatively
inexpensive. However, straw has the potential to introduce weed seeds. A fine grade
compost provides nutrients in organic forms and improves surface moisture retention

(Beard, 1973). Crumb rubber (5 to 6 mm particle size) can provide higher temperatures

for longer periods of time as a result of its black color. Easily applied, crumb rubber
protects the crowns of turfgrass plants, which is important for sod survival in heavy
traffic situations (Rogers et al., 1998). Hydrated fiber mulch consists of shredded paper
pre-mixed with water into a slurry and applied through a hydroseeder or hydroplanter
(Beard, 1973). Hydroseeders and hydroplanters are bulky machines that are relatively
costly compared to other methods of mulching. Pelletized fiber consists of compressed
pellets of shredded paper applied by a drop spreader. When the mulch is irrigated the
pellets swell and provide a uniform cover. Clay loam native soil as a mulch mimics
traditional seed establishment conditions, combining seed-to-soil contact with an
adequate nutrient holding capacity.

This experiment was designed to assess the effect of these different mulches on"
turfgrass germination and establishment, specifically under soil-less growing conditions
(Ecomat® on plastic). The experimental design included comparison of two turfgrass
species: Poa supina (supina bluegrass with a stoloniferous growth habit), and Lolium

perenne (perennial ryegrass with a bunch type growth habit).

MATERIALS AND METHODS

The experimental design was a 2 x 8 x 4 (species x mulch type x seeding date)
split-plot randomized complete block design with three replications. Each of the 48
refined wood fiber plots measured 1.2 m x 0.9 m. The refined wood fiber (Ecomat®) is
an erosion control mat produced by Canadian Forest Products in New Westminster,
British Columbia. Plots were located at the Hancock Turfgrass Research Center on the
Michigan State University campus in East Lansing, Michigan. Two turf species, Poa
supina “Supranova” (Saatzucht Steinach GmbH, Steinach, Germany) and Lolium perenne
“Manhattan 11” (Turf Merchants, Hubbard, Oregon), were seeded at the recommended
rate of 7.6 g m'2 and 20 g In2 respectively. Four mulches (pellet mulch, hydro mulch,
crumb rubber, and native soil) were applied at rates that resulted in equal coverage to a
0.6 cm depth; where, no seed was visible to direct sunlight. The polymer mulch was

2. A control

applied at 5 g m’z, and the straw was laid at a depth of about 1 bail per 45 m'
treatment without mulch was included. The four seeding dates, 3 July 1995, 29
September 1995, 5 July 1996, and 1 October 1996, represented traditionally both adverse
(summer) and ideal (fall) seeding times for establishment of cool season grasses.
Fertilizer was applied to all plots once per week for four weeks using 13-25-12 starter
fertilizer at 4.9 g P m'z. Frequent fertilization was necessary because of the absence of a
soil medium to hold nutrients for the developing turfgrass plants. No additional
rnicronutrients were provided for the duration of the experiments. Percent cover was
visually estimated every 7 days afier seeding (DAS) for 4 weeks to determine turfgrass
density (0-100%). Daily high and low temperatures were recorded for the 28 DAS, and
irrigation was applied as needed. The data were analyzed for statistical differences using

analysis of variance. Treatment means were separated using Fischer’s LSD with a or/2 of

0.05.

10

RESULTS

Critical time during seed germination is the first 28 DAS, and differences among
the four seeding dates occurred as a result of the different environmental conditions that
existed (Figure 1). For the fall 1996 seeding date (D), the daily temperatures were well
below the optimum growing temperatures for cool season turfgrasses. Significant
differences between turf species, mulch type and seeding date occurred throughout the
experiment (Table 1).

Lolium perenne developed significantly greater cover than Poa supina when the
synthetic polymer, crumb rubber, straw, and compost were used as mulches (Table 2).
The pelletized fiber mulch, hydrated fiber mulch and straw, regardless of turf species,
produced significantly greater turfgrass cover than the control while the synthetic
polymer, crumb rubber, and compost only showed greater turfgrass cover with Lolium

perenne indicating an interaction between turf species and mulch type.

ll

 

 

12 3 4 56 7 8 910111213141516171819202122232425262728

DAS

 

Figure 1.1 Daily high and low temperatures (C) 28 days after

seeding (DAS) for 3 July 1995 (A), 29 September 1995 (B), 5 July
1996 (°C), and 1 October 1996 (D) seeding dates. [I Indicates optimal
temperature range for cool season turfgrass growth. — Indicates daily
average temperature.

12

Table 1. Significance of treatment effects for turfgrass cover on Ecomat® mulching
study, East Lansing, MI. 1995-96.

 

 

Days afier seeding
Source 7 14 21 28
Turf Sp. (TS) *4! 1* ti **
MUICh type (M) *II *4! ** *t
T x M NS ** * *
Seeding date (D) ** ** ** **
TS x D *1! *1! *III **
M x D an: an M: an
TS x M x D * ns ns ns

 

*, ** Significant at the 0.05, 0.01 probability levels, respectively.
us Not significant at the 0.05 probability level.

Table 2. Turf species by mulch type interaction 28 days after seeding averaged over four
seeding dates, East Lansing MI. 1995-96.

Percent cover (%)

 

Mulch type Poa supina Lolium perenne
Control 11.9 11.3
Polymer 1 1.9 22.8
Pellet mulch 42.7 44.0
Hydro mulch 34.5 42.8
Crumb rubber 19.8 30.3
Native soil 9.3 11.8
Straw 36.8 54.1
Compost 13.8 30.2

 

LSDms) 9.0

13

Overall, the straw, pelletized fiber mulch, and hydrated fiber mulch appeared to
be the best mulches for turfgrass cover regardless of the seeding date (Table 3). All three
mulches resulted in consistently greater turfgrass cover than the control with the
exception of the fall 1996 seeding date. The crumb rubber in the fall of 1995 showed a
significantly greater turfgrass cover versus the other three seeding dates. This is likely a
result of the dark color, and poor water holding capacity of the crumb rubber where,
during hot and dry growing conditions (summer seeding trials) the crumb rubber was not
able to hold sufficient moisture. The compost as mulch showed significant differences in
turfgrass cover versus the control for the first two seeding dates but not during the second
year of seeding. The consistency of the compost may have deteriorated fiom the first
year (1995) giving inconsistent results during the second year of testing, because the
turfgrass cover for the compost treatment was much greater during both seeding dates in
1995 than in 1996. The percent turfgrass cover for the fall 1996 seeding date is likely a
result of the low temperatures limiting turfgrass germination (Figure 1). Daily
temperatures for the first 28 DAS were below optimal growing conditions for turfgrass
growth, including 5 days where the temperatures dropped below freezing. Even on days
where the temperatures reached optimal growing conditions, the average temperature for
that day was still too cold. Therefore, sub-optimal growing conditions existed for all 28

DAS.

14

Table 3. Mulch type by seasonT interaction 28 days after seeding averaged over turfgrass
speciest, East Lansing, MI. 1995-96.

Percent cover (%)

 

Mulch type Summer 1995 Fall 1995 Summer 1996 Fall 1996
Control 11.5 14.2 19.8 1.0
Polymer 21.5 19.5 26.7 1.8
Pellet mulch 45.0 64.2 55.2 9.0
Hydro mulch 44.2 51.5 53.8 5.0
Crumb rubber 9.0 65.2 18.3 7.7
Native soil 7.3 12.7 21.5 0.8
Straw 44.3 52.5 79.7 5.2
Compost 33.5 40.7 10.8 3.0
LSD§ (0.05) I 3 .0

LSD1(0.05) 16.6

 

1’ Includes 1995 (3 July, 29 September) and 1996 (5 July and 1 October) seeding dates.
1 Species includes Poa supina and Lolium perenne.

§ LSD (0,05, for different mulches within the same seeding date.

1] LSD (0.05) for different seeding dates within the same mulch type.

15

Both turfgrass species showed significant differences in turfgrass cover for the
four seeding dates (Table 4). The summer 1995 and fall 1995 seeding dates showed that
Lolium perenne did significantly better than Poa supina, which was to be expected
because of its faster germination rate. The interaction that is occurring where the Poa
supina did not have greater turfgrass cover than the Lolium perenne during the summer
and fall 1996 seeding dates.

Among the seven mulches tested, straw, pelletized fiber mulch, and hydrated fiber
mulch were the best mulches for providing the greatest turfgrass cover regardless of the
seeding date. However, the crumb rubber mulch was very effective when growing

conditions were less favorable for the other mulches, and more optimal for the rubber

(fall 1995).

16

Table 4. Turf species by season'r interaction 28 days after seeding averaged over all
mulch typesI and the control, East Lansing, MI. 1995-96.

Percent cover (%)

 

Turfgrass sp. Summer 1995 Fall 1995 Summer 1996 Fall 1996
Poa supina 15.6 30.0 41.0 3.8
Lolium perenne 38.5 50.1 30.5 4.6
LSD’wm) 14.6

LSD‘rooa 8.3

 

‘1 Includes 1995 (3 July, 29 September) and 1996 (5 July and 1 October) seeding dates.

I Mulches include polymer, pellet mulch, hydro mulch, crumb rubber, native soil, straw,
and compost.

§ LSD (0.0,, for different mulches within the same seeding date.

1] LSD (005, for different seeding dates within the same mulch type.

17

DISCUSSION

Although the effectiveness of mulching has been ascertained during this
experiment, the question of the relative effectiveness of mulch materials naturally arises.
Ahnost any lifeless material can be used for mulching, but the relative effectiveness of
the different mulch materials varies according to their physical and chemical properties
(Harris and Yao, 1923). The moisture content of the mulches varies depending on their
physical and chemical properties, and the total moisture lost from the seedbed surface
varies accordingly. That is to say, the more absorptive the mulch the more moisture is
lost from the seedbed. Since the purpose of a mulch is to protect the seedbed surface
from exposure to the physical agencies of evaporation, the less absorptive the mulch the
less water is brought up to the surface to be exposed and therefore the more moisture is
held in the seedbed. Harris and Yao (1923) compared mulches for growing vegetable
crops and found there was a correlation between the moisture lost from the soil and the
moisture contained in the mulches. Harris and Yao (1923) concluded in their experiment
that the straw mulch was the best because it had a lower capillary rise than the hay, wood
shavings and manure mulches tested, and this is also supported by the results found in
this experiment. Similar findings were also concluded in previous research describing
the physical and chemical properties of different mulches. For instance, both King
(1895) and Wollny (1866) determined the effectiveness of mulching is brought about by
diminishing the direct influence of the agencies of evaporation and by retarding the
capillary rise of water to the surface of the mulch.

The 0.6 cm depth of the native soil and compost as mulches may have been too

deep for the seed to properly germinate, because the light was too limiting. In addition, if

18

moisture was not a problem as a result of capillary rise, the depth of mulching and the
water holding capacity of both the native soil and compost could have been a limiting
factor. Too much water in the native soil and compost may have resulted in anaerobic
conditions, and in turn limited the germination potential of both turf species investigated.

The use of the polymer as a mulch was unsuccessful because it did not protect the
germinating seed from the direct elements of the sun and wind. The direct exposure to
full sun and wind greatly reduced the establishment potential of both turf species. The
use of a polymer augmented these criteria, by absorbing any available water, making it
unavailable for the seed.

Aside from maintaining a consistent environment for seed germination, the length
of time a favorable environment is provided by mulching is also important. This is
especially important for turfgrasses that require many days to germinate such as Poa
supina.

Turfgrass germination and density was enhanced with the use of a mulching
material. The greatest turfgrass density was achieved when straw, pellet mulch, and
hydro mulch were applied, respectively. Crumb rubber performed equally as well only
during the fall 1995 seeding date when temperatures were cooler. Finally, the faster

germinating Lolium perenne had greater turfgrass density than Poa supina.

Chapter 2

THE EFFECT OF DIFFERENT GROWTH MEDIA FOR TURFGRASS

ESTABLISHMENT AND PERFORMANCE

ABSTRACT

W: Turfgrass establishment

The germination and establishment of Poa pratensis and Poa supina in four
different growth media (sand, pine wood mulch, Ecomat®, and SportGrass") placed over
plastic'sheeting was investigated. Percent turfgrass cover (0-100%) as a measure of
germination density was evaluated 1, 2, 5, and 10 weeks after seeding. The study began
10 June 1996 and was restarted on 12 August 1996. Results determined that SportGrassm
was the most successful growing medium for turfgrass establishment. The Ecomat" did
not have as high turfgrass cover as the SportGrassm, because the watering requirements
for the Ecomat® was much greater than the SportGrassm. Establishing turf from seed
with different growth mediums, of different water holding capacities under one irrigation
block results in too much or too little water being applied to each growth medium. There
were no significant differences between turfgrass species ten weeks after seeding.
W: Turfgrass performance

The athletic field performance of Poa supina sod grown on four different growth
media over plastic were compared. Washed Poa supina sod was included as a control.
Crumb rubber topdressing was applied as a split treatment on the five sod types. The

plots were subjected to simulated athletic field traffic under reduced light conditions.

19

20

Results showed the use of crumb rubber contributed to higher turfgrass density. No
significant differences in turfgrass density between sod types occurred, because not

enough wear was applied to show potential differences.

21
INTRODUCTION

Maximizing footing and minimizing player injury are two criteria expected from
turf fields by athletic field managers. Having a tough, shear resistant turf is one way to
augment these criteria. However, turfgrass is living plant material and when exposed to
heavy athletic or recreational use, the quality of the turf will deteriorate. To maintain a
tough, shear resistant turf, resodding is often implemented. In sod production and in
installation, tear-resistant turf that quickly roots is most desirable (Hall, 1993).

Shear strength of sod is the force required to tear or break a piece of cut sod apart
(Hall, 1993). In the case of conventional sod, shear strength is dependent upon the
remaining root mass after harvesting, rhizomes and/or stolons, soil type, and moisture
content (Rogers and Waddington, 1992). Additionally, sod produced over an impervious
layer like plastic increases shear strength as a result of the dense and intact root mass
provided.

Sod produced on plastic is a method of turfgrass establishment that possesses
many benefits. One of the greatest benefits of sod on plastic is the ability to select the
desired growth medium. Choosing a particular growth medium can reduce the likelihood
of problems commonly associated with conventional sodding practices. For instance,
choosing a non-soil-growing medium can eliminate soil layering. In addition, selecting a
growth medium that contributes to increasing turf shear strength also has practical
applications. However, comparative research between establishing turfgrass on plastic
using various growth media, and how they perform under traffic as an established turf is

limited, and warrants further investigation.

22

PM: Turfgrass establishment

For this study, four different growth media were investigated for turfgrass
establishment using two turfgrass species. The four growth media selected for this study
were, pine mulch, sand, refined wood fiber mat (Ecomat®) and SportGrassm topdressed
with sand. The pine mulch, sand, and SportGrassm are three growth media currently in
use for sod production over plastic. SportGrassm is a woven polyethylene mat with
synthetic strands intended to provide additional support for the turfgrass. The Ecomat® is
a refined wood fiber mat available in large rolls (40 m x 1.5 m), and provides a very light
weight and stable surface for turfgrass establishment. The two turfgrass species selected
were Poa supina var. ‘Supranova’ and Poa pratensis var. ‘Touchdown’. Both species are
cool season turves used for athletic fields. P. pratensis has a rhizomatous growth habit,

and P. supina has a stoloniferous growth habit.

2mm: Turfgrass performance

Poa supina performs well under reduced light conditions when exposed to (high
traffic) athletic field conditions’(Stier, 1997). Optimum fertilizer levels and applications
of plant growth regulators (PGRS) for the management of P. supina under reduced light
conditions have been determined (Stier, 1997), but further research is warranted to
improve the wear resistance of the turfgrass.

Previous research has shown that compost grown sod over plastic performed as
well or better than conventional sod grown commercially (Cisar and Snyder, 1992), and
the basis of tear resistance for compost grown and commercially grown sod, were

noticeably different. For this experiment, established Poa supina sod was investigated

23

for athletic field use in low light conditions. The P. supina was established within four
different growth media over plastic (pine wood mulch, Ecomat®, SportGrassm, and,
compost) and a fiflh treatment washed Poa supina was included. The pine wood mulch,
Ecomat® and SportGrassm sods were selected from the Part one: Turfgrass establishment
study. Pacific Sod Company (Camullo, California) grew the compost sod in California
(nine months old), and the washed sod was grown in Nepean, Ontario, Canada, by the
Manderley Sod Company (18 months old).

Further attempts to reduce wear through the use of crumb rubber as a topdressing
material has been proven to be an effective amendment for reducing surface compaction
and turfgrass wear (Rogers et al., 1998). Therefore, the inclusion of crumb rubber
topdressing as a second treatment to improve the overall performance of the turfgrass
under high traffic and low light conditions was investigated. The purpose of this study
was to compare the four growth media with crumb rubber topdressing, exposed to

extreme conditions including high traffic and reduced light situations.

24

MATERIALS AND METHODS

We: Turfgrass Establishment

The experimental design was a 2 x 4 factorial randomized complete block design
with three replications. The 24 plots were 7.3 m x 2.8 m, and randomized over black 6
mil polyethylene sheeting at the Hancock Turfgrass Research Center (HTRC), Michigan
State University. The four growth media included sand, pine wood mulch, SportGrassm
(SportGrassm Ltd., Richmond, Virginia) and Ecomat® (Canadian Forest Products Ltd.,
New Westminster, British Columbia) Sand and pine mulches were laid over the
polyethylene sheeting at a 20-mm depth. The SportGrassm was rolled out over the
polyethylene sheeting back filled with 25-mm of sand, with the individual strands
vertically aligned. Each growth media gave the appearance of a shallow seeding bed.
Poa supina var. ‘Supranova’ and P. pratensis var. ‘Touchdown’ were seeded on 3 June
1996 at 4.9 g m‘z. All plots were then mulched with PennMulch® at 37 kg 100 m".
Fertilizer was applied on 3 and 10 June 1996 using 12-25-12 Starter Fertilizer at 4.9 g P
m'z. On 17 June 1996 73 mm of rain in 90 minutes washed out the entire study. The
experiment was restarted on 12 August 1996 following the above protocol. Fertilizer
applications were applied at the beginning of each week for the first four weeks using the
13-25-12 Starter Fertilizer at 4.9 g P m'z. Three fertilizer applications were applied every
two weeks using 18-3-18 at 2.5 g N m'2 beginning 13 September 1996. Irrigation was
applied as needed using an automatic irrigation system, and by hand watering. The hand
watering was required because the four growth media each had different watering
requirements. Percent turfgrass cover was visually measured at two, three, five, and ten

weeks after seeding.

25

Ram: Turfgrass performance

Poa supina var. ‘Supranova’ sod was grown on four different growth media (pine
wood mulch, sand, Ecomat®, and SportGrassTM) during the summer of 1996 at the
Hancock Turfgrass Research Center (HTRC) on the campus of Michigan State
University. On 11 November 1996 fifteen 1.2 m x 1.2 m x 0.15 m depth boxes were
sodded over a sandzpeat mix (80:20 v/v) inside the indoor turfgrass research facility at the
HTRC, Michigan State University. This facility, constructed of sheerfill II fiberglass
fabric (Chemical Fabrics Corporation, Buffalo, NY), was an air-supported structure (600
m2) designed to simulate the conditions inside the Pontiac Siverdome (Stier, 1993). The
sheerfill H fiberglass fabric is a white cover that allows neutral density light to pass
through (approximately 9 to 13%) Poa supina sod grown in the pine wood mulch,
Ecomat®, and SportGrassm growth media, P. supina sod grown in compost from the
Pacific Sod Company in California, and washed P. supina sod from Manderley Sod
Company in Nepean, Ontario were sodded on individual boxes. The compost-grown sod
(50 m depth) and washed sod were delivered to the HTRC in spring 1996 and were
maintained outside on plastic until they were moved inside on 11 November 1996. On 27
December, each plot was split and cmmb rubber was topdressed at a 19-mm depth.

The experiment was setup as a randomized complete block design (RCBD)
growth media as a factor, and crumb rubber as a split plot on the first factor. Factor A
consisted of the four different media and the washed sod. Factor B was the crumb rubber
topdressing applied to one half of the Factor A plots. Fertilizer was applied twice per
month at 2.5 g N m’2 using Lebanon Country Club 18-3-18 fertilizer until the end of
April 1997. Traffic applications were applied two times a week using molded soccer
cleats (thirteen 14-mm studs per shoe), 10 January 1997 through 11 April 1997. A total
of 50 jogging passes were applied during each traffic application to simulate typical
athletic field wear. PGR (Trinexapac ethyl) was applied on 8 December 1996 at 0.13 ml
m‘z, and on 7 January 1997, 26 February 1997, and 28 March 1997. Chlorosis and

26

browning of the leaf tips became apparent after the second PGR application. Therefore,
the appearance of PGR toxicity accounts for the rate reduction, and lag between the 7
January and 26 February PGR applications. Iprodione (Chipco®) was applied on 10
December 1996, 29 January 1997, and 8 March 1997, afier Microdochium nivale (pink
snow mold) became visible. The Iprodione was applied at 1.3-ml a.i. m’z. Mowing was
done every Monday, Wednesday, and Friday at 32 m using a reel mower. Watering
was done on an as needed basis, and fans were used to provide air movement across the
turf. Color, density, and quality ratings were visually taken every two weeks. Color and
quality ratings were based on a 1-9 scale with 1 being the dead or bare ground, 9 being
the ideal turf and 6 being acceptable. Turfgrass cover was visually estimated as a percent
cover. Clippings were collected and weighed weekly. Clegg and shear vane data were
also collected to measure surface hardness and turf shear strength. The Clegg meter
measures surface hardness in gravity deceleration (Gm), and shear vane measured lateral

turf strength in Newton meters (Nm) (Stier, 1997).

27

RESULTS

23119112: Turfgrass establishment

Successful turfgrass establishment can be determined after the first 10 weeks of
seeding, and differences between the different growth media existed (Table 5). The
significance for the two treatment effects for percent turfgrass cover, at two, three, five,
and ten weeks after seeding determined the SportGrass" provided greater turfgrass
density than the Ecomat®, pine wood mulch, and sand, respectively (Table 6). P00

supina had significantly greater turf cover only at five weeks after seeding (Table 6).

28

Table 5. Part one: Turfgrass establishment — Significance of treatment effects for
turfgrass coverI, East Lansing, MI. 1996.

 

 

 

Weeks after seeding
Source 2 3 5 10
Turf species (T) ns ns * ns
Growth media (G) * ** ** **
T x G ns ns ns ns

 

*, ** Significant at the 0.05 and 0.01 probability levels, respectively.
ns Not significant at the 0.05 probability level.
1' Turfgrass cover was visually estimated on a percent (0-100%) scale.

Table 6. Part one: Turfgrass establishment — Turfgrass coverI (0-100%) for turfgrass
species and growth media established as sod on plastic, East Lanm MI. 1996.

 

 

 

 

Weeks afier seeding

Turfgrass sp. 2 3 5 10
P00 pratensis 2.1 5.3 30.6 42.8
Poa supina 2.2 6.9 37.9 51.8
LSDmos) ns ns * ns
Growth media

Pine mulch 1.8 5.0 15.2 35.8
Sand 1.3 2.8 12.0 18.8
Ecomat® 2.0 3.3 19.5 36.7
SportGrassm 3.3 13.2 90.3 97.8
LSD ns 2.4 7.9 14.4

 

ns Not significant at the 0.05 probability level.
1' Turfgrass cover was visually estimated on a percent (0-100%) scale.

29

Ram: Turfgrass perfbrmance

The fiberglass fabric of the indoor research facility transmitted approximately
11% :l: 2% sd sunlight. The temperature inside was normally maintained at 16.8 d: 0.9 °C
sd; temperature extremes ranged from 3-23 °C. Relative humidity (RH) averaged 44.8%
:1: 6.2 sd with a range of 24-70% RH. The fiberglass fabric provided relatively neutral
shading. As expected, the high pressure sodium lamps provided a high proportion of
their radiation in the yellow to red wavelengths (Stier, 1997).

No important significant differences occurred among either factor (growth media
and crumb rubber topdressing) for color ratings (Table 7). Significant differences in turf
cover between plots with crumb rubber versus plots without crumb rubber existed (Table
8) during the final three rating periods (13, 31, and 28 March 1997). The plots with
crumb rubber had greater turfgrass cover (Table 8). The increased turf cover on the "
crumb rubber plots resulted in significantly higher quality turf ratings (Table 9).
However, turfgrass cover and quality did not differ significantly among the five different
growth media. Clipping yields determined no significant differences among treatments
(Table 10).

30

Table 7. Part two: Turfgrass performance — Effect of traffic on turf color’ of supina
bluegrass grown on different growth media with crumb rubber topdressing as a split, East
Lansing, MI. 1996-97.

 

 

 

 

Color

Growth media 8/ 12 27/12 17/01 4/02 17/02 13/03 21/03 28/03
Ecomat 7.5 7.3 6.0 5.1 5.0 6.3 6.7 6.5
SportGrass 8.0 7.7 6.6 6.3 5.6 5.4 6.3 6.4
Compost 5.8 7.0 7.0 7.7 6.8 6.5 7.0 7.0
Pine mulch 6.5 7.7 7.0 7.8 6.7 6.6 7.0 6.8
Washed sod 7.0 7.5 6.6 5.6 5.5 6.9 7.0 6.3
LSD 1.4 ns 0.7 0.7 ns 0.8 ns ns
Topdressing

No 7.0 7.4 6.5 6.4 5.9 6.2 6.8 6.6
Yes 7.0 7.4 6.8 6.6 5.9 6.5 6.8 6.6
LSD ns ns ** ns ns * ns ns

 

*, ** Significant at the 0.05 and 0.01 probability levels, respectively.
ns Not significant at the 0.05 probability level.
T Color was rated visually on a 1-9 scale: 1=100% brown, 9=dark green.

Table 8. Part two: Turfgrass performance — Effect of traffic on turf coverT of supina
bluegrass grown on various growth media with crumb rubber topdressing as a split, East
Lansing, MI. 1996-97.

 

 

 

% cover
Growth media 8/ 12 27/ 12 17/01 4/02 17/02 13/03 21/03 28/03
Ecomat 97.7 98.7 98.3 98.7 96.0 93.2 90.5 90.8
SportGrass 100.0 100.0 98.7 97.3 94.8 87.5 75.0 74.2
Compost 98.7 99.0 98.2 98.3 99.0 89.7 88.8 88.3

Pine mulch 97.7 99.7 98.5 98.5 99.0 89.7 85.0 82.2
Washed sod 99.3 100.0 98.8 98.7 99.0 92.7 86.3 86.0

 

LSD ns ns ns ns ns ns ns ns
Topdressing

No 98.7 99.5 98.2 97.9 97.0 88.7 82.1 80.5
Yes 98.7 99.5 99.0 98.7 98.1 92.4 88.2 88.1
LSD ns ns * ns ns ** * **

 

*, "”" Significant at the 0.05 and 0.01 probability levels, respectively.
ns Not significant at the 0.05 probability level.
T Turf cover was visually estimated on a percent (0-100%) scale.

31

Table 9. Part two: Turfgrass performance — Effect of traffic on turf quality!r of supina
bluegrass grown on various growth media with crumb rubber topdressing as a split, East
Lansing, MI. 1996-97.

 

 

 

 

Quality
Growth media 8/ 12 27/ 12 17/01 4/02 17/02 13/03 21/03 28/03
Ecomat 7.7 7.5 6.9 5.3 4.5 6.6 6.8 6.6
SportGrass 8.2 7.7 7.3 6.8 5.1 5.3 5.5 5.8
Compost 6.5 6.8 7.4 7.8 6.8 6.2 7.4 6.5
Pine mulch 7.5 7.8 7.6 7.9 6.8 6.4 6.8 6.3
Washed sod 7.5 7.7 7.0 6.3 4.9 6.4 6.6 6.3
LSD ns ns ns 0.9 1 .6 ns ns ns
Topdressing
No 7.5 7.5 7.2 6.7 5.6 6.0 6.4 6.1
Yes 7.5 7.5 7.3 6.9 5.6 6.4 6.8 6.5
LSD ns ns ns ns ns ** ** *

 

*, " Significant at the 0.05 and 0.01 probability levels, respectively.

ns Not significant at the 0.05 probability level.

1' Quality was rated visually on a 1-9 scale: 1=100% necrotic turf/bare soil, 9=dense,
uniform turf with acceptable color (color 2 5). -

Table 10. Part two: Turfgrass performance — Effect of traffic on clipping yields of supina
bluegrass grown on varying growth media (GM) with crumb rubber (CR) topdressing as a
split, East Lansing, MI. 1997.

 

 

Clipping yields (grams)I
Growth media 17/01 24/01 31/01 7/02 28/02 7/03 14/03 21/03 28/03
Ecomat 0.3 0.4 0.5 0.4 3 .2 3 .2 1.3 1.9 1.7
SportGrass 0.5 0.7 0.5 0.6 3.6 2.9 1.1 1.6 1.7
Compost 0.7 0.9 0.6 1.0 3.8 4.2 1.0 1.6 1.2

Pine mulch 0.4 0.8 0.7 1.0 3.3 3.7 1.0 1.3 1.8
Washed sod 0.5 0.6 0.5 0.5 3.7 4.3 1.6 2.2 1.9

 

LSD ns ns ns 0.4 ns ns ns ns ns
Topdressing ,

No 0.5 0.6 0.5 0.7 3.4 3.4 1.3 1.7 1.6
Yes 0.5 0.7 0.6 0.7 3.7 3.9 1.0 1.8 1.8
LSD ns ns ns ns * ns ns ns ns

 

*,** Significant at 0.05 and 0.01 probability levels, respectively; ns = not significant at p =
0.05.
T Clippings Were collected using a reel mower set at 3.2 cm, and weights were measured in

grams.

32

Surface hardness characteristics differed significantly among the two treatments
(growth media and crumb rubber topdressing) tested. SportGrassTM plots had a
significantly harder surface (64.0 Gm) than any other growth media (Table 11). Plots
treated with crumb rubber exhibited significantly lower surface hardness characteristics.

The SportGrassTM , Ecomat®, and washed sod had significantly higher shear
strength readings than the compost and pine wood mulch (Table 11). Additionally, plots
topdressed with crumb rubber had significantly lower shear strength than the plots
without crumb rubber (Table 11).

Interactions show that the growth media without crumb rubber topdressing had a
significantly greater shear strength than the media with crumb rubber (Table 11) except
for the washed sod and pine wood mulch treatments. The rubber likely had not worked
into the mat layer during the 3 January rating date (Rogers et al., 1998). Differences in
March showed that there were differences with rubber among plots with backings

(Ecomat® and SportGrass").

33

Table 11. Part two: Turfgrass performance — Effect of surface hardness'r and shear
strength1 on Poa supina grown on varying growth media with crumb rubber topdressing
as a split, East Lansing, MI. 1997.

 

 

 

 

 

 

 

Date

3 Jan. ' 3 Jan. 29 March
Growth media (GM) Clegg (Gum) Shear Vane (nm) Shear Vane (nm)
Ecomat (EM) 51.8 14.6 22.8
SportGrass (SG) 64.0 17.1 24.2
Compost (CF) 40.1 15. 1 16.6
Pine mulch (PM) 41.3 13.5 13.1
Washed sod (WS) 51.8 21.1 20.4
LSDms) 4.2 2.9 4.1
Crumb rubber (CR)
No 51.7 20.1 21.9
Yes 48.1 12.4 16.9
LSD ** ** it
GM x CR
EM — CR 54.7 17.7 27.5
EM + CR 49.0 11.5 18.0
SG - CR 67.7 23.5 31.7
86 + CR 60.3 10.7 16.7
CF — CR 40.8 18.2 18.2
CF + CR 40.3 12.0 15.0
PM — CR 43.0 16.0 12.7
PM + CR 39.7 11.0 13.5
WS - CR 52.3 25.2 19.3
WS+CR 51.3 17.0 21.5
1.302015, ns 3.3 3.2
LSD‘W, ns 4.3 4.6

 

*,** Significant at the 0.05 and 0.01 probability levels, respectively.

us Not significant at p = 0.05.

1 Surface hardness was measured using the Clegg Impact Soil Tester in gravity
deceleration (GM).

1 Shear strength was measured using the Eijelkamp Shear Vane in Newton meters

(nm).

§ Between crumb rubber levels with same grth media.

1] Between growth media with same or different crumb rubber levels.

34

DISCUSSION

Earning: Turfgrass establishment

Although significant difference between the four growth media existed, the
question of the relative accuracy of these results naturally arises. Because the four
grth media differed so much in physical characteristics it was nearly impossible to
treat each grth medium with the optimal management practices necessary for turfgrass
establishment. The experimental design made the watering requirements necessary for
each treatment virtually impossible to provide. Chapter One showed that dense turfgrass
could be established on the Ecomat® in only 28 days after seeding when the PennMulch®
was used. However, in this experiment the Ecomat® only achieved 37% density ten
weeks after seeding (70 days after seeding). This occurred because the Ecomat® did not .
receive satisfactory moisture during the initial stages of seed germination. The pine
wood mulch also had a poor turfgrass density ten weeks after seeding because it too did
not receive satisfactory moisture during the initial stages of seed germination. For the
sand, repeated shifting and washing of the growth medium during water applications
resulted in low turfgrass cover. The SportGrass" had the greatest turfgrass density
because it was the grth medium that received the optimal watering regimes during
seed germination. In addition the polyethylene fibers of the SportGrass" provided ideal
stability for the back filled sand.

Baum: Turfgrass performance

Beard (1973) noted that sod possessing a particle size substantially different from
the underlying soil had a cleavage plane at the interface. However, Cairol and Chevallier
(1981) found that cleavage did not appear when a good incorporation of pine bark into
the upper 20 mm of the underlying soil was noticed, and the knitting was very satisfying
regardless of the intensive or medium traffic conditions applied. Conversely, the findings

in this experiment determined significant differences in cleavage (shear strength)

35

occurred among the different growth media tested for turfgrass density. However, unlike
the findings by Cairol and Chevallier, the pine wood mulch and compost had
significantly lower shear strength than the SportGrass", Ecomat®, and washed sod. The
lower shear strength for the pine wood mulch may also be attributed to the stress
provided by the reduced light levels. Root mass and growth is severely limited when
turves are exposed to low light conditions (Stier, 1997). Therefore, rooting in the pine
wood mulch was likely limited to the mulch itself and the instability of the wood
mulching material lessened the shear strength of the sod. In addition, the blades of the
shear vane apparatus on penetrate 2.5 cm into the turf; therefore, the shear strength of the
pine wood mulch was only measuring the growth medium and not the sand root zone.

Rogers etal., (1998) determined that topdressing turfgrass with crumb rubber
initially lowers turfgrass shear strength, and maintains higher turfgrass density when
subjected to heavy traffic. They also found that shear vane numbers increased as the age
of the turf increased with topdressing. In this experiment the crumb rubber topdressing
had a different particle size than the underlying growth media, and is likely the cause for
the lower shear strength as a result of topdressing crumb rubber. This supports the
findings by Rogers and Vanini (1998), and Beard (1973). Maintaining higher turfgrass
density with crumb rubber topdressing and providing lower surface hardness supports the
findings by Rogers and Vanini (1998).

Chapter 3

THE EFFECT OF SEEDING RATE AND FERTILIZER SOURCE AND RATE
ON TURF GRASS ESTABLISHMENT ON PLASTIC

ABSTRACT

For experiment one, seeding study, the germination and establishment of four
turfgrass species (Poa pratensis, Poa supina, Lolium perenne, and F estuca arundr'nacea)
within a refined wood fiber mat (Ecomat®) were evaluated using three different seeding
rates over plastic sheeting. The three seeding rates were 1, 2, and 4 times the
recommended seeding rates for each turfgrass species, respectively. Results determined
that four times the recommended seeding rate significantly increased turfgrass cover from
the recommended seeding rate, and that Lolium perenne had the greatest turfgrass cover.
F estuca amndinacea, had significantly greater turfgrass density than both Poa species.

For experiment two, fertility study, the germination and establishment of Poa
pratensis in Ecomat® was evaluated using different fertilizer sources and rates. Two
nitrogen sources (Milorganite® and ammonium nitrate) were studied using three
application rates (1.25, 2.5, and 5.0 g N m’2 every two weeks). The Milorganite® at the
middle and high rate had significantly higher turfgrass density than all other treatments.
The experimental design for both the seeding and fertility studies severely decimated the
results of both experiments. Final results are inconclusive because optimal water

requirements were unattainable for proper seed germination.

36

37

INTRODUCTION

Manufactured in New Westminster, British Columbia, by Canadian Forest
Products Ltd., Ecomat® is used extensively as an erosion control mat for use along
roadsides. Ecomat® is a recycled wood fiber mat and can be used as the growth medium
on plastic sheeting for turfgrass establishment. Sod production on plastic is a unique
practice and demonstrates many advantages versus traditional sod production. Root
shearing during sod harvesting is eliminated when grown on plastic which allows the sod
to establish faster than conventional sod. The sod is light-weight due to the absence of
soil, potentially allowing for cheaper shipping costs and larger sod pieces. The sod
pieces are held together by the binding of the roots, thus enabling the production of
turfgrasses with bunch type growth habits. Since the Ecomat® is a soil less growing
media, the recommended seeding rates and fertilizer rates and type will differ from
conventional turfgrass establishment in soil. Currently, sod production on plastic utilizes
wood chips, compost, and sand as the growth media for turfgrass establishment.
Although sod production on soil less growing media has been practiced for a number of
years, little published research exists to recommend specific establishment practices. In
1997, two separate experiments were conducted to satisfy the following objectives: 1)
Determine the optimum seeding rate for turfgrass establishment on a soil less media
(Ecomat®) over plastic, and 2) Determine the optimum fertilizer type (organic vs.
mineral) and application rate for turfgrass establishment on a soil less media (Ecomat®)

over plastic.

Experimentme: Seeding study
Too much seed slows turfgrass maturity (Madison, 1966). Because of excessive
seedling competition, seedlings cannot develop until some factor, usually disease,

decimates the population so surviving individuals have space to grow (Crocker and

38

Barton, 1957; Wells and Robinson, 1954). Conversely, too little seed results in a sparse
stand, and while the grass slowly fills in, the area is open to weed invasion (Madison,
1966). Therefore, knowing the proper seeding rate prior to seeding affirms the possibility
of achieving a more mature turfgrass stand.

Recommendations for seeding rates are based on an assumed number of seeds per
unit (generally seeds/ pound or gram) (Christians, et al., 1979). Estimates of the number
of seeds per gram for Poa pratensis in current use range from 4,800 to 4,960 seeds per
gram, and this differs from the estimates required for F estuca arundinacea
(approximately 500 seeds per gram (Beard 1973; Musser and Perkins, 1969). Poa supina
has a similar seed size to Poa pratensis, and Lolium perenne has a similar seed size to
F estuca arundinacea, and their respective seeding rates are approximately the same.

For this experiment, four turfgrass species (Poa pratensis, Poa supina, Lolium
perenne, and F estuca arundinacea) were seeded into Ecomat® over polyethylene
sheeting using three different seeding rates (one, two, and four times the recommended
seeding rates). Because the Ecomat® is a soil-less growing medium, the vital seed to soil
contact does not exist for turfgrass establishment. Therefore, the optimal seeding rates on

Ecomat® for each species need to be investigated.

W: Fertility study

Various recommendations on rates, ratios, and placement of fertilizer for turfgrass
establishment have been made (Davis, et al., 1964; Harper, et al., 1962; Skogley, 1962).
In particular, the recommendations vary in the amounts of phosphorous recommended
relative to nitrogen and potassium (King and Skogley, 1969). In addition, the amount of
nitrogen suggested varies (King and Skogley, 1969). Establishing turfgrass in a relatively
inert material such as the Ecomat®, nutrient availability and holding capacity is limited,

and increased fertilizer application rates may be warranted.

39

To combat the detrimental effects of compaction on soil physical properties for
heavily trafficked turfgrass areas, sandier growing media are being used (W addington, et
al., 1990). Zimmerman (1969) reported that increasing sand in the rootzone mix
decreased cation exchange capacity and available nutrient levels. This same effect also
exists when Ecomat® is used as the growing media. Using organic sources of nitrogen is
one way to aid in compensating for the low nutrients in the growth media without
changing the physical properties in growing media such as sandy soils and Ecomat®.
Effects of an organic fertilizer (Milorganite®) rate resulted in increased concentrations of
phosphorous, potassium, calcium, sulfur, manganese, iron, copper, and zinc for turfgrass
establishment in a sand growing medium (Waddington, et al., 1990).

For this experiment, different sources of nitrogen (Milorganite® and ammonium
nitrate) were investigated at different rates (1.25, 2.5, and 5 g N m'z) for Poa pratensis
establishment in Ecomat® over polyethylene sheeting. In addition, one rate of urea (2.5 g
N m'z) and two rates of phosphorous and potassium (2.5 and 5.0 g P or K m'z) were
investigated as orthogonal contrasts to the 2.5 g N m'2 ammonium nitrate fertilizer

treatment.

40

MATERIALS AND METHODS

W: Seeding rate

Four cool season turfgrasses were established from seed in Ecomat® over
impermeable polyethylene sheeting (6 mil thickness) at the Hancock Turfgrass Research
Center, Michigan State University, during summer 1997. The experiment was a 2 factor
randomized complete block design (RCBD) with 3 replications. Factor one was the four
turf species, which included: Poa pratensis L. (Kentucky bluegrass), P. supina Schrad.
(supina bluegrass), Lolium perenne L. (perennial ryegrass), and F estuca arundinacea
Schreb . (tall fescue). Factor two was the three seeding rates for each turf species (Table
12). The initial seeding rate was the typical recommended seeding rate for conventional
turfgrass establishment on soil (Turgeon, 1991). There was a total of 36- 1.22 m by 1.83
m plots which were seeded on 7 June 1997. Seed was applied using a hand shaker, and
each plot was individually seeded. Straw was mulched over the seeded plots. Prior to
seeding all plots were fertilized with 5 g N rn'2 using Lebanon Country Club (13-25-12)
Starter Fertilizer. Every two weeks an additional 2.5 g N m’2 was applied using the 13-
25-12 fertilizer for a total of seven fertilizer applications. Water was applied, as needed
using an automatic irrigation system. Mowing began four weeks after seeding, and was
done twice per week using a reel mower at a 32 mm mowing height. Turf density was

visually estimated to determine percent turfgrass cover for establishment.

Table 12. Seeding rates (g m'z) for turfgrass establishment on four turf species, East
Lansing, MI. 1997.

 

 

Tudgrassgpecies
Seeding rate P. pratensis P. supina L. perenne F. amndinacea
1x 7.3 7.3 39.1 39.1
2x 14.7 14.7 78.2 78.2

3x 29.3 29.3 156.4 156.4

41

W: Fertility type and rates
On 10 June 1997, 45 0.91 m by 1.22 m EcomatTM plots were laid on plastic, with

0.5 m Poa pratensis sod strips between each plot to act as a buffer. The study consisted
of six main treatments consisting of two fertilizer types (two forms of nitrogen (N)), and
three fertility rates with five replications (Table 13). The two types of fertilizers used
were a organic fertilizer (MilorganiteTM 6-2-0), and a mineral fertilizer (ammonium
nitrate 34-0-0). The three fertility rates compared were 1.25, 2.5, and 5 g N m'z. An
additional three treatments were included for orthogonal contrasts with the 1.25 g N m'2
ammonium nitrate treatment (Table 13). The additional treatments included high
potassium, high phosphorous, and using urea as the mineral form of nitrogen. The urea
(46-0-0), phosphorous (0-46-0), and potassium (0-0-50) were applied at 1.25 g N rn'2
every two weeks. High nitrogen and phosphorous treatments were applied prior to
seeding as a bed source of nutrients. Four post fertilizer treatment applications were
made every two weeks after seeding. Table 2 shows the arrangement of the fertilizer
treatments. On 11 June 1997 all plots were seeded with Poa pratensis var. ‘Touchdown’
at 7.3 g m'z, and then mulched with straw. Water was applied, as needed using an
automatic irrigation system. Mowing began four weeks after seeding, and was done
twice per week using a reel mower at a 32 mm mowing height. Turfgrass cover was

estimated visually on a percent scale.

42

Table 13. Fertilizer treatment types and rates for Poa pratensis establishment within
Ecomat® over plastic, East Lansing, MI. 1997.

 

 

Treatment] Bed Ni Post: N Bed P Post P Bed K Post K
1 10(0) 1.25 1 10 ‘ 1.25 o 1.25
2 10 (0) 2.5 10 1.25 o 1.25
3 10 (0) 5.0 10 1.25 o 1.25
4 10 (M) 1.25 10 1.25 o 1.25
5 10 (M) 2.5 10 1.25 o 1.25
6 10 (M) 5.0 10 1.25 o 1.25
7 10 (M) 2.5 10 2.5 o 1.25
8 10 (M) 2.5 10 1.25 o 2.5
9 10 (U) 2.5 10 1.25 o 1.25

 

1' Treatment rates are all in g m'z.

1 Post treatments began two weeks after seeding and were applied every two weeks.
=organic form of nitrogen (Milorganitem), M=mineral form of nitrogen (ammonium

nitrate), and U=mineral form of nitrogen (urea).

43

RESULTS

W: Seeding study

Significant differences in turfgrass cover among the four turf species studied
occurred (Table 14). Lolium perenne had significantly greater cover than any of the other
turf species investigated on all five sampling dates (Table 14). F estuca amndinacea had
significantly greater turfgrass cover than both Poa pratensis and Poa supina. The greater
turfgrass cover of the Lolium perenne and F estuca amndinacea were expected on the
early data collection dates because, of their superior germination rate than the two Poa
sp. These results were anticipated, because Lolium perenne and F estuca amndinacea are
faster germinating turves. However, even after two months, the two Poq sp. had
significantly less cover than the Lolium perenne and F estuca amndinacea. Overall, only
the Lolium perenne had what would be considered acceptable turfgrass cover two months
afier seeding (76.3%).

Significant differences in turfgrass cover among the three seeding rates occurred
on all sampling dates except the 2 July rating date (Table 14). Differences between the
1x rate and the 4x rate were significant for all turfgrass cover sampling dates. When
seeding at the recommended seeding rate, turfgrass cover was relatively poor even after

two months.

44

Table 14. Seeding study — Effect of three seeding rates on turfgrass coverT for four
turfgrass species utilizing Ecomat® on plastic, East Lansing, MI. 1997.

 

 

 

 

Date

2 July 18 July 30 July 8 Aug. 8 Sept.
Turf species (TS) % cover
Poa praiensis‘ (KBG) 0.2 13.7 15.1 16.7 19.2
Poa supina: (SBG) 1.3 12.0 17.7 19.6 23.0
Lolium perenne§ (PRG) 29.7 74.1 71.9 73.0 76.3
F estuca arundinacea§ (TF) 12.9 40.0 37.6 37.0 41.1
LSDmos) 10.7 19.0 18.1 17.6 18.9
Seeding rate (SR)
1x (times) recommend rate 5.4 23.0 23.6 24.6 27.3
2x (times) recommend rate 12.8 37.3 36.2 36.8 41.3
4x (times) recommend rate 14.9 44.6 46.9 48.3 51.3
LSDmos) ns 16.5 15.7 15.2 16.4
TS x SR
KBG x 1x 0.0 6.0 7.7 9.7 11.0
KBG x 2x 0.7 21.7 21.7 24.3 28.3
KBG x 4x 0.0 13.3 16.0 16.0 18.3
SBG x 1x . 0.0 2.7 2.3 2.7 3.0
SBG x 2x 0.0 3.3 17.3 17.7 24.3
SBG x 4x 4.0 30.0 33.3 38.3 41.7
PRG x 1x 20.0 65.0 65.0 66.7 71.7
PRG x 2x 38.3 84.0 79.0 80.0 82.3
PRG x 4x 30.7 73.3 71.7 72.3 75.0
TF x 1x 1.7 18.3 19.3 19.3 23.3
TF x 2x 12.0 40.0 26.7 25.0 30.0
TF x 4x 25.0 61.7 66.7 66.7 70.0
LSDmos) ns ns ns ns ns

 

ns Indicates no significance at the p = 0.05 probability level.

1 Turfgrass cover was visually rated on a percent scale (0-100%).

1 The recommended seeding rate for P. pratensis and P. supina is 7.3 g m'z.
§ The recommended seeding rate for L. perenne and F. arundinacea is 39.1 g m’z.

45

W: Fertility study

Significant differences in turfgrass cover occurred within each factor on all four
sampling dates (Table 15). Significant interactions between the two factors (nitrogen
fertilizer type and rate) also occurred. These results indicate that the use of an organic
fertilizer (Milorganite®) significantly increased turfgrass cover during establishment
compared to the mineral nitrogen source (ammonium nitrate). This supports conclusion
found by Waddington, et al., (1990); where, the use of an organic fertilizer increased
turfgrass establishment in sandy soils that had low cation exchange capacity and nutrient
availability.

Simply increasing the rate of nitrogen fertility significantly increased turfgrass
cover. These results determined that 2.5 g N rn'2 (every two weeks) using the organic
fertilizer was required to increase turfgrass cover (Table 15). King and Skogley (1969)
also concluded that increased nitrogen rates increased turfgrass growth or establishment

rate.

46

Table 15. Fertility study — Effect of fertilizer type and rate on turfgrass coverT for
establishing Poa pratensis within Ecomat® over plastic (seeded 11 June 1997), East

Lansing, MI. 1997.

 

 

 

 

 

Date

10 July 30 July 8 Aug. 8 Sept.
Fertilizer type (FT) % cover
Milorganitef (M) 11.4 29.0 31.5 35.5
Ammonium nitmte§ (AN) 3.9 14.3 12.7 14.9
LSD III :0! III III
Fertilizer rate (FR) '
1.25 g m'2 (A) 3.5 15.8 13.9 16.6
2.5 g m'2 (B) 9.1 21.6 23.6 26.2
5 g m'2 (C) 10.5 27.5 28.8 32.8
LSDmos) 3.2 7.0 8.2 9.6
FT x FR
M x A ‘ 2.6 14.8 13.6 15.6
M x B 15.2 33.0 38.0 42.0
M x C 16.6 39.2 43.0 49.0
AN x A 4.4 16.8 14.2 17.6
AN x B 3.0 10.2 9.2 10.4
AN x C 4.4 15.8 14.6 16.6
1.813%, 4.2 9.0 10.6 12.3

 

* Indicates significance at the 0.01 probability level.

1‘ Turfgrass cover was visually estimated on a percent cover scale (0-100%).
1 Milorganite® has a 6-2-0 analysis.

§ Ammonium nitrate has a 34-0-0 analysis.

47

No significant differences occurred in turfgrass cover when the post phosphorous
and potassium application rates were doubled (Table 16). Again, this supports findings
by King and Skogley (1969) where turfgrass response to different levels of phosphorous
was inconsistent.

Finally, establishment results between the two types of mineral nitrogen sources
(ammonium nitrate and urea) investigated had no significant differences occur in

turfgrass cover (Table 16).

Table 16. Fertility study — Effect of increasing post phosphorous and potassium rates, or
using urea nitrogen on turfgrass coverT for establishing Poa pratensis within Ecomat®
over plastic, East Lansing, MI. 1997.

 

 

 

 

 

Date

10 Jul} 30 July 8 Aug. 8 Sept.
PhosphorousI rate % cover
1.25 g m'2 2.0 10.2 9.8 11.8
2.5 g m'2 7.2 16.2 17.2 20.2
LSD ns ns ns ns
Potassium§ rate
1.25 g m'2 1.8 10.2 9.8 10.8
2.5 g m'2 3.6 18.6 13.8 15.6
LSD ns * ns ns
Nitrogen form 2.5 g m'2
Ammonium nitrate 2.4 10.2 9.8 14.2
Urea 4.6 17.8 18.8 24.6
LSD ns ns ns ns

 

"‘ Indicates significance at the 0.01 probability level, ns = not significance at p = 0.05
probability level.

1' Turfgrass cover was visually estimated on a percent cover scale (0-100%).

I Additional phosphorous was applied using super phosphate 0-46-0.

§ Additional potassium was applied using sulfate of potash 0-0-50.

48

DISCUSSION
Environmental:

Results from the two experiments are somewhat inconclusive, because weather
and more importantly water played a critical role to decirnate the outcome of the two
studies. Unfortunately, the configuration of the experiments made watering a near
impossible task. Conflicts in watering requirements between the two studies eliminated
the practical application of the automatic irrigation system. Therefore, hand watering
was necessary and became the primary method for irrigating. In addition, any rainfall
that occurred flooded the plots (especially the fertility study). Often the plots were under
water from rainfall or the irrigation. Conversely, if the plots were not flooded they were

often too dry for proper seed germination and establishment.

W: Seeding study

It was determined that the seeding at four times the recommended seeding rate
significantly increased turfgrass density. However, the repeated flooding and drying out
of the plots as a result of the watering problems severely limited the potentials of each
species. The poor outcome of the study eliminated the application of a secondary test to
determine turfgrass maturity. Because the turves did not establish to an acceptable level
(density), the intended root box study was abandoned. Root box pulls were to be done to
determine the amount of rooting for each turf species investigated at the three different
seeding rates. It was anticipated to find that, although the four times seeding rate
provided the greatest turfgrass density that the plants were too immature as a result of

over crowding. In turn, reduced rooting would be evident.

Experimentm: Fertility study
It is likely that the organic nitrogen source (Milorganite®) did significantly better

than the mineral nitrogen source (ammonium nitrate) as a result of the test site being

49

poorly drained. This in turn, led to too much water accumulating as a result of rainfall or
too much irrigation. On many occasions the research plots were submerged under water
for long periods of time (as long as 24 hours), and denitrification of the ammonium
nitrate likely occurred; therefore, greatly reducing the amount of available nitrogen
required for the germinating plants. However, it is likely that the poor results of the
ammonium nitrate was because of runoff as a result of the repeated flooding that occurred
(Waddington et al., 1994). Denitrification probably did not occur because the
decomposing carbon source and the chemoheterotrophic bacteria necessary to break
down the nitrate were not present in the Ecomat® (Foth and Ellis, 1988). Conversely, if
there were any effects from the ammonium nitrate fertilization, it would likely have
caused toxicity (burn) to the immature seedlings. In addition, the high volume of
Milorganite® may have been adding to the physical properties of the Ecomat®, and in turn
providing a more favorable seedbed for turfgrass establishment.

Similar to the Seeding study, the application of a root box study to determine
fertilizer effects on rooting was abandoned as a result of the unacceptable turfgrass

density.

50

CONCLUSIONS

The effectiveness of Ecomat® as a growth medium for turfgrass establishment has
been ascertained during these experiments. However, protocol to achieve successful seed
germination and establishment has only been initiated: It has been determined that
Ecomat®, as an established sod, has the potential to provide an instant turfgrass cover that

is durable, lightweight, and quick rooting.

Chapteume: Mulching study

The objective of this experiment was defined, and it was determined that the use
of particular mulches can greatly enhance turfgrass density. The straw mulch especially,
enhanced more favorable growing conditions for the germinating seed. In addition, the
PennMulchTM and hydro mulch provided more favorable growing conditions for the
germinating seed. The physical properties of the mulches determined their effectiveness.
The mulches with the presumed larger pore spaces had lower capillary rise potential;

therefore, water was not moved away from the germinating seed as easily.

The Lolium perenne had germinated sooner and had greater density 28 days after
seeding. These results were anticipated because of the more rapid germination rate of L.
perenne than Poa supina; therefore, making the mulch a more important component as

germination time increases.

Chm: Turfgrass establishment and performance

Unfortunately, the configuration of the establishment experiment impeded much
of the attainable results. Because of the repeated washing of the study as a result of
rainfall, the germination and establishment conditions for the P00 pratensis and P. supina

were not acceptable, particularly on the sand, Ecomat®, and pine wood mulch growth

51

media. In any event, the SportGrass" was very effective for establishing turfgrass,
despite the unfavorable watering regimes, and produced the densest turf. No significant
differences occurred between the two Poa species.

Turfgrass performance under heavy traffic and low light conditions determined
that all growth media were capable of providing acceptable turfgrass density for the
duration of the experiment. These acceptable turfgrass densities were augmented with

the addition of crumb rubber topdressing.

W: Turfgrass seeding and fertility studies

The configuration and location of both the seeding and fertility studies severely
impeded the potential outcomes of the experiments. Any rainfall or more than three
minutes of irrigation was generally enough water added to submerge portions or all of the
studies under water. These flooding conditions often persisted for long periods of time
(as long as 24 hours) due to the rains.

Increasing the seeding rate in Ecomat® to four times the recommended rate
increased turfgrass cover. The Lolium perenne had the greatest turfgrass cover.

Organic nitrogen (Milorganitec’) established denser Poa pratensis turf than the
ammonium nitrate. This is likely a result of the organic nitrogen being more of a slow
release nitrogen, therefore providing nitrogen to the germinating seed for a longer period
of time. The poor performance of the ammonium nitrate could be attributed to run of as a
result of the frequent flooding of the plots.

Finally, using a different source of nitrogen fertilizer like urea (46-0-0) and/or
increasing the concentration of phosphorous or potassium had no significant effects on

turfgrass establishment (percent cover).

52

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