THE EFFECT OF VARYING- SOIL MOISTURE,
FERTILIZATION, AND HEIGHT OF CUTTING
ON THE QUALITY OF TURF

By
WILLIAM H. DANIEL

A THESIS
Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY
Department of Soil Science
1950

ACKNOWLEDGMENT
The author wishes to express his appreciation to
Dr. James Tyson and Dr. C.M. Harrison for their guidance
and assistance throughout the course of this investigation.
He is also indebted to Dr. L.M. Turk, Dr. J.Q. Lynd, and
Dr. E.P. Whiteside for their helpful suggestions in the
preparation, of the manuscript, and to the Detroit District
Golf Association, U.S.G.A. Green Section, and Midwest■Turf
Foundation for the fellowship which made this study possible.

TABLE OF CONTENTS

PAGE
I.
II.
III.

INTRODUCTION

1

REVIEW OF LITERATURE

2

GREENHOUSE EXPERIMENTS

4

A. Methods
B. Results and Discussion
1. Relation of Growth to Soil Moisture
Ranges
a. First growth period
b. Second growth period
c. Third growth period
d. Summary of growth and moisture
relations
2. Moisture and Nitrogen Relations
a. Yield of fertilized and unfert­
ilized grasses
b. Nitrogen availability under
excess moisture
3. Root Growth in Relation to Moisture
Supply
4. Root-top Ratios of Seedlings
IV.

V.
VI.
VII.

FIELD EXPERIMENTS

4
12
12
12
17
22
25
30
30
34
35
38
42

A. Methods

42

B. Results and Discussion
1. Soil Moisture Conditions
a. Seasonal conditions during
irrigation period
b. Soil moisture ranges
2. Yield of Clippings
3. Turf Rating
4. Composition of Turf
5. Ability of Turf to SupportGolf Balls

47
47
47
48
56
59
62
68

SUMMARY AND CONCLUSIONS

71

LITERATURE CITED

77

APPENDIX

79

INTRODUCTION
Irrigation, mowing, and fertilization have been used
with varying degrees of success in attempting to grow the
type of fairway turf which golfers demand.

Lack of knowledge

concerning relationships of soil moisture, fertility, and
height of cut to growth of fairway grasses and weed has
often resulted in failure to produce the desired turf.
More knowledge is necessary in order to grow a thick,
compact turf which will: (1) resist the invasion of weeds
and undesirable grasses, (2) offer a minimum of resistance
to the forward progress of a driven ball, (3) hold the ball
at suitable heights above the soil surface and not inter­
fere with the forward motion of the club-head in making
shots, (4-) afford the golfer a firm stance, and (5) pre­
sent a pleasing landscape all season long.

More information

is needed to find how little water may be used in supple­
mental irrigation, its efficiency, and effects of various
soil moisture levels on the growth of grasses.
The objectives of this investigation were to study
the interactions of irrigation, height of cut, and fertility
upon the growth of some grasses commonly grown on fairways
in the northern humid regions.

An effort was made to evalu­

ate the influence of these practices on the quality of fair­
way turf.

REVIEW OF LITERATURE

The relationships that exist between soil moisture
supply, height and frequency of cutting, fertility levels,
and the growth of grasses have been studied in part by many
Investigators.
Wilson (27), Melton and Wilson (17) > and Richards and
Weaver (25) used the adsorption soil point method, developed
by Livingston (15)» to study soil moisture conditions under
bluegrass and clover turf on golf courses and lawns.

Melton

and Wilson (17) showed that a soil permitting a sorption
block to absorb 500 mg. water an hour contained sufficient
water for good growth of lawn grasses.
The comparison of several methods of measuring soil
moisture are given by Kelley, et al. (12) and Slater and
Bryant (24).

The former point out that two factors are of

importance in moisture relations, the volume of water per
mass and the availability of the moisture.

Their conclusion

was that the plaster of paris blocks were more adaptable for
measuring soil moisture than other methods then available.
This electrical resistance method developed by Bouyoucos and
Mick (2,3,5*6,7) was used to study the effects of soil moist­
ure on turf during this investigation.
Results of investigators on the physiological effects
of differential cutting and fertilization agree very closely.
Harrison (10) used bluegrass, fescue, and bent under three
cutting heights, one-fourth, one and one-half, and three in­
ches.

He was able to reduce greatly the roots of the low-cut

3
grasses in 16 five-day periods of cuttings. Mineral fert­
ilizers applied did not overcome this effect of low-cutting.
G-raber (9) points out that bluegrass may be closely clipped
or grazed for one or two seasons -with good results, but a
decline in productivity is certain.

Kuhn and Kemp (13) and

Loworn (16) cut grasses at five heights relative to the
leaf ligule and invariably found that frequent and close
cuttings reduced the growth of foliage, roots, and rhizomes.
The importance of fertilizer use on turf has been
well illustrated by Montieth and Bengtson. (18) and V/elton
(26).

They reported extensive tests on old fairways where

recovery was due to fertilizers alone.

The aggressiveness of

bentgrass is shown by Musser (20) in a study of mixed turf
under different pH and phosphorus ranges.

Bluegrass and fes­

cue were unable to compete with bent grass under conditions
considered optimum for the slower growing grasses.
Bouyoucos (4), using plaster

of parts blocks, found

little moisture movement during a period of 30 days in soils
having a moisture content below their moisture equivalent.
He concluded that capillary rise in soil was of little im­
portance to growing crops.

In calibrating soil moisture blocks,

Anderson and Edlefsen (1) found much less lag in. the block
readings when growing roots were present in the soil since a
greater soil moisture gradient was established.
Soil compaction and physical conditions of soil water
movement have received much attention, as related to turf
management, especially in putting greens.

Mott (19) states

that, in poorly aerated soils, a reduction of nitrates to
ammonia occurs and plants lacking in oxygen cannot absorb
potassium.

Compaction studies of Lawton (14-) confirm the

idea that decreased
soils.

potassium uptake occurrs in compacted .

Larger additions of potassium fertilizers were re­

commended under these conditions to increase uptake of this
element.

Physical analysis of soils such as those of Humbert

and Grau (11) show that soil mixtures containing approximately
70 per cent sand are best for the putting green.
GREENHOUSE EXPERIMENTS
Methods
In December 194-8 moisture studies were begun in the
greenhouse using 60 three-gallon, glazed jars.

Fifteen cul­

tures each of Astoria bent, Kentucky bluegrass, and Creeping
Red fescue were started in Hillsdale sandy loam soil and
fifteen cultures of Kentucky bluegrass were started on Brookston clay loam.

Three cultures of each group were left as

unfertilized checks and the remaining twelve fertilized.

The

twelve fertilized cultures of each group were divided into
four soil moisture ranges with three replications of each.
All unfertilized cultures were maintained in the high soil
moisture range.
The Hillsdale sandy loam soil with a pH of 5.0 was
relatively high in potash and medium in phosphorus content.
The area from which this soil was taken had been in sod for
several years and was farmed prior to that.

The physical

5
structure of this soil was very good because of its coarse
sand content and the aggregation due to previous grass growth.
The Brookston clay loam soil was very granular, had
a pH of 6.8, and was well supplied in available nutrients.
This heavy soil was used for contrast to the more sandy and
open Hillsdale series, as soil type greatly influences moist­
ure and aeration conditions.
Each culture contained 12 kilograms of screened soil,
and the fertilizer was hand mixed
of 1,500 pounds of 10-6-4 per acre.

into the soil at the rate
A Bouyoucos soil moisture

block was'placed on edge midway (four inches from the bottom)
in each pot.

Twenty-four nylon and thirty-six plaster of paris

blocks were used.

The nylon units were used in the extreme

moisture ranges because they are more sensitive than the plast­
er of paris blocks.
On December 13 fescue and bluegrass were planted at
-J

the rate of one teaspoon of seed per culture.

The bent grass

which germinates faster, was planted on January 4, 1949 at
the rate of one-half teaspoon of seed per culture.

These

grasses were permitted to grow until well established when
the resulting turf was clipped to one and one-fourth inches.
A careful record was kept of the amount of water app­
lied to each culture during the experiment.

In most cases

1,200 ml. of water, equal to 10 per cent by weight of the
soil, was applied at one time.

Readings of the soil moisture

blocks were taken periodically to determine the soil moist­
ure available to the grasses. -The reading of the individual
block determined the amount of water and time of application

6
FIGURE 1. CALIBRATION CURVE FOR NYLON SOIL MOISTURE
BLOCKS IN HILLSDALE SANDY LOAM SOIL USED
IN GREENHOUSE AND FIELD PLOTS
(SEE TABLE 1)
0 % AVAILABLE

LOO,OOO

20 % AVAILABLE

10,000

50 % AVAILABLE

100 % AVAILABLE
1,000

10

20

PER CENT MOISTURE IN SOIL

7
Table 1. Resistance of nylon blocks, per cent available soijL
moisture and soil moisture content in Hillsdale sandy loam.
Table based on calibration curve in Fiacre 1.
Ohms
Ohms
Per cent Per cent
Per cent
Per cent
Resistance Available
Moisture Resistance Available Moisture
30.3
6000
200
263
8.5
45
28.5
8.4
6500
44
245
250
27.0
230
7000 .
300
8.3
43
26.0
220
42
8.1
7500
350
24.0
200
8.0
8000
41
400
22.5
8500
. 40
185
450
7.9
21.0
170
9000
500
7.7
39
20.0
160
7.6
9500
550
37
19.0
150
36
600
-IO9OOO
7.5
18.3
7.4
143
650
11,000
35
17.7
12,000
700
.34,.
137
7.3
17.2
132
7.2
13,000
750
32
16.7
800
127
14,000
7.1
31
123
16.3
7.0
850
15,000
30
15*9
900
119
16,000
6.9
29
15.5
6.8
17,000
28
950
115
15.0
110
1000
18,000
6.7
27
14.5
105
1100
6.6
19,000
26
14.0
100
1200
20,000
6.5
25
13-5
1300
6.4
22,000
24
95
13.0
90
1400
24,000
6.3
23
12.7
6.2
1500
26,000
22
87
12.4
84
28,000
21
1600
6.1
12.1
81
1700
6.0
30,000
20
1800
11.9
35,000
79
5-9
19
11.7
5.8
1900
40,000
18
77
2000
11.5
45,000
75
5.7
17
2100
50,000
5.6
73
16
11.3
2200
11.1
55,000
71
5.5
15
2300
60,000
5-4
69
14
10.9
2400
65,000
67
10.7
5.3
13
66
2500
12
10.6
70,000
5.2
2600
75,000
65
11
10.5
5-1
64
2700
80,000
5.0
10.4
10
2800
85,000
63
4.9
10.3
9
61
4.8
2900
90,000
8
10.1
60
10.0
100,000
4.7
7
58
9.8
4.6
.
110,000
6
3400
57
120,000
9.7
4.5
1
5
56
3600
130,000
4.4
4
9 •6
3800
140,000
55
4.3
9.5
3
4.2
4000
2
150,000
53
9.3
4200
52
4.1
1
9.2
175,000
4400
4.0
51
0
200,000
9.1
4600
50
3.8
9.0
240,000
4800
49
300,000
3.5
8.9
48
5000
8.8
400,000
3.3
5500
47
3.0
500,000
8.7

ms

8
to a given culture in order to keep the available soil moist­
ure within the desired range.
A modified Wheatstone bridge, Bouyoucos Soil Moisture
Bridge, Model C (3), designed for testing the soil moisture
blocks, v/as used throughout the experiment.

The readings in

ohms resistance were converted to per cent available moisture
by calibrating duplicate samples as described by Bouyoucos
and Mick (2,3).

Supplementing these data were many weight-

reading comparisons of actual conditions in cultures in the
greenhouse.

A total of 172 points was plotted for the curve:

for nylon blocks as shown in Figure 1.

From this curve

values such as 100, 50, 20 and 0 per cent available moisture
were interpolated.

The curve v/as used for 100 block locations

both in the greenhouse and field plots, as a reference for all
conditions and treatments on the Hillsdale soil.

Variations

were least in the mid portion of the curve and greatest at
the low moisture end.
The calibration curve for the plaster of paris blocks,
shown in Figure 2, v/as established similarly to that of the
nylon block curve.

Fifty-four readings were secured from

greenhouse cultures to compare with the usual block calibrat­
ion described by Bouyoucos and Mich (3).

Figures 3 to 5 and

10 to 15 are based on these two curves.
Four ranges of soil moisture were maintained in the
main experiment.

The heaviest application of water was

made to the "excess'’ soil moisture cultures in which the soil
v/as maintained above 100 per cent available moisture after

FIGURE 2. CALIBRATION CURVE FOR PLASTER OF PARIS
SOIL MOISTURE BLOC'KB IN HILLSDALE SANDY LOAM '
SOIL USED IN GREENHOUSE. ( SEE TABLE 2. }•

AVAILABLE
100,000

M

-'50 % AVAILABLE
1,000

itm
AVAILABLE

o

5

10
PER CENT

15
20
SOIL MOISTURE

25-

10
Table 2. Resistance reading of plaster of paris blocks, per
cent available moisture and soil moisture content of Hills­
dale sandy loam soil. Table based on calibration curve
of Figure 2.
Ohms
Per cent
Percent
Ohms'"
Per cent Per cent
Resistance Available
Moisture Resistance Available Moisture
16.0
2800
200
120
29
6.9
3000
15.0
28
6.8
250
110
14.0
300
100
3200
27
6.7
13.2
3400
6.6
92
26
350
12.5
400
3600
85
25
6.5
450
3800
12.0
80
24
6.4
4000
500
11.6
76
23
6.3
550
600
650
700
750
800
850
900
950

73
70
67
64
61
59
57
55
53

11.3
11.0
10.7
10.4
10.1
9.9
9.7
9.5
9.3

1000
1100
1200
1300
1400

52
48
46
44
42

9.2
8.8
8.6
8.4
8.2

1600
1700
1800
1900
2000
2200
2400
2600

39
38
37
36
35
33
31
30

7.9
7.8
7.7
7.6
7.5
7.3
7.1
7.0

4400
5000
5500
6000
6500
7000
8000
9000
10,000
11,000
12,000
13,000
14,000
16,000
20,000
22,000
26,000
30,000
40,000
50,000
70,000
90,000
120,000

22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0

6.2
6.1
6.0
5*9
5.8
5-7
5-6
5-5
5-4
5.3
5.2
5-1
5-0
4.9
4.8
4.7
4.6
4.5
4.4
4.3
4.2
4.1
4.0

the beginning of the first growth period.

This was increased

to saturation, (Figure 3) and was completely saturated dur­
ing the following growing periods.

The latter conditions were

maintained by the regular addition of small amounts of water.
The "high11 soil moisture range varied from 150 to 50
per cent available soil moisture.

This range has been shown

by Schleusner, et al. (23) to be the most favorable for plants
it gave the greatest production and most succulent growth.
The "medium" soil moisture range was maintained be­
tween 120 and 20 per cent available soil moisture.

This

range was sufficient to keep the grass growing but tended to
retard grass growth between the water applications.

This

range was planned as one requiring the least irrigation poss­
ible to maintain satisfactory turf growth.
The "low" soil moisture range varied from 100 to 0
per cent available moisture, which was from 14 to 4 per cent
total soil moisture.

Grass wilted (See Plate 1 and 2) to

some degree for as much as five days between applications of
water. 'Water was added frequently enough to prevent the
grass from becoming dormant.
These variations of the soil moisture levels will be
referred to as excess, high, medium, and low soil moisture
ranges throughout the following discussion.
The response of the grasses to available soil moisture
in the greenhouse study was measured in terms of height of .
growth, dry weight of clippings, water required to maintain
the cultures, and water required to produce a unit of dry

wilted
recovered
Plate 1* Illustration of wilting occurring in low soil
moisture range for bentgrass on Hillsdale soil. Cul­
ture on left had progressively wilted for three days
at 70°F. and bO% relative humidity.

wilted
recovered
Plate 2. Effect of wilting on appearance of bluegrass.
Moisture content of clippings was 6Q% in wilted, Ql%
in normal grass.

Bentgrass
Fescue
Bluegrass
Plate 3« A comparison of three grasses at low moisture range.

matter.

Harvest was made by clipping at one and one-fourth

inches when a renewal of the moisture cycles occurred.

The

growth was measured following three growing periods of 27,
34, and 43 days, respectively.
Results and Discussion
Relation of growth to soil moisture ranges
First Growth Period—

This period was started after

the turf was well established and extended from March 3 to
March 30.’ During this time the greenhouse was thermostatically
controlled at 650 to 75°F.

The relative humidity varied from

30 to 100 per cent, but usually it was about 40 per cent.
Changes in moisture levels were started March 3 at. the same
time as the designated first growth period.

The responses

of the grasses to moisture changes are shown in Table 3«
The replications agreed very closely and only the average is
reported.
Although the bentgrass grew less in height than the
other grasses it produced the greatest dry weight of material.
The large response of the bent to high soil moisture supports
the results of Musser (20).

3ent grass is a vigorous grass

that responds to high fertilization and high moisture.

The

more fertile Brookston clay loam soil produced slightly
greater yields of bluegrass than the Hillsdale sandy loam,
but the height of growth was about the same.

All three grass­

es in the low soil moisture range cultures produced nearly
the same dry weight because they were limited in moisture
and had been allowed to wilt on three occasions during the

14
Table 3. Effect of four soil moisture ranges on the height
of growth, dry weight of clippings, and the amount of
water applied to three grasses growing on two soils.
Averages of three replications during first growth period.
~ Grass
Soil
'
Moisture Ranges
series
Excess
High
Medium
Low
Height of growth, cm.*
bentgrass Hillsdale
fescue
Hillsdale
bluegrass Hillsdale
bluegrass Brookston

21
22
22
23

16
17
20
21

14
15
17
16

11
13
17
15

Dry Weight of Clippings, gms.
. bentgrass Hillsdale
10.7
fescue
Hillsdale
7.7
bluegrass Hillsdale
5.7
bluegrass Brookston
6.7

9.4
5.2
5-2
5.7

4.4
3.7
3.7
3.9

3.1
3.4
3-3
3.5

Water Added,
. bentgrass
fescue
bluegrass
bluegrass

7.0
7-9
7.4
7.7

3.6
5-4
3*6
4.2

3.0
3-0
3.0
3.2

2.9
2.9
3.2
3.2

Average of Above Grasses & Soils
Height of growth, cm.
22.0
Dry weight of clippings, gms. 7-7
Water applied, liters
7.5

18.0
6.4
4.2

15.6
3.9
3.1

14.0
3.3
3.1

liters
Hillsdale
Hillsdale
Hillsdale
Brookston

* Clipped one and one-fourth inches above surface of soil.
27 day growth period.
in Plates 1 and 2.

Examples of such wilting are shown

As shown in Figure 3 the available soil •

moisture in the representative cultures was near zero between
each water addition.

The comparative growth rate is shown

in Plate 3 where bent, fescue, and bluegrass were grown
under uniform conditions.
Plates 4, 5» and 6 give a comparison of the relative
growth response to the different moisture ranges as main­
tained during the first growth period.

Culture 4 in the

bentgrass produced the highest yield (10.7 grams) and culture
1 in the bent grass produced the lowest yield (3-1 grams).

FIGURE 5. PER CENT OF AVAILABLE, SOIL MOISTURE IN FOUR MOIST
RANGES"" UNDER BENTCjRASS CULTURES DURING FIRST GROWTH PERIOD

soil

£00

maintained a f
saturation

Mo i s t u r e

RANGES' .;

PER

CENT

OP AVAILABLE .SOIL

MOISTURE

medium

12
DAYS

IB
OF

GROWTH

A comparative growth of three grasses during the first
growth period on Hillsdale sandy loam soil. Moisture
ranges are indicated below each picture.

low
medium
high
excess
Plate 4. Bentgrass. Excess water applied did. not
reduce growth during this period.

i

low
medium
high
excess
Plate 5. Fescue. Table 3 shows relative height and
yield of these grasses.

I

excess
high
medium
low
Plate 6 . Bluegrass. Note variation in turf height
for the different soil moisture ranges.

17
The gradual Increase toward complete saturation of the
soil in the excess soil moisture range cultures, shown in
Figure 3, had not had time to reduce the yield of grass in
the first period.

However, examination of the soil in these

jars showed that the roots, which forme-rly extended through­
out the soil mass, had died hack during the three weeks
period, leaving roots only in the upper three inches of soil.
Meanwhile, a concentration of new roots occurred at the sur­
face of the soil and at the edges of the culture.

It was

these roots that enabled the turf to exist under the saturated
moisture conditions of the later experiments.

The large

amount of water applied to the excess soil moisture range
cultures is explained by the fact that they contained approx­
imately 2 liters of free water at the end of the first growth
period.

They were maintained at this level until the end of

the greenhouse experiment.

Thus the water used by the plants

was actually less than the seven and one-half liters listed
for the first period.
Second Growth Period—

The second growth period ex­

tended for 34- days from March 30 to May 3»

The first growth

period was terminated after 27 days when there was a definite
increase, to complete saturation, in the excess soil moisture
range cultures.

Following the first growth period all moist­

ure levels were maintained uniformly to the conclusion of the
experiments.
Table 4 gives an average of the three replications
during the second growth period.

In the excess soil moisture

18
Table 4. Effect of four moisture ranges on the height and
dry weight.of grass clippings during second growth period.
Soil
series
Height of Growth, cm.bentgrass Hillsdale
fescue
Hillsdale
bluegrass Hillsdale
bluegrass Erookston

Soil Moisture Ranges
High
Medium
Excess

Low

9
12
13
10

18
15
24
21

13
12
16
16

Dry Weight of Clippings,gms.
bentgrass Hillsdale
fescue
Hillsdale
bluegrass Hillsdale
bluegrass Brookston

3-3
4.1
2.9
2.2

8.2
6.3
8.8
9.4

. 7.2
3.9
5-1
6.7 -

6.0
3.4
4.6
7.3

Water Added ,
bentgrass
fescue
bluegrass
bluegrass

5-2
5-1
5-2
4.5

6.0
6.4
7.2
7-5

4.0
4.4
5.1
6.7'

3.9
4.3
4.8
5-7

Aye. of Above Grasses & Soils
Height of growth, cm.
11
Dry weight of clippings,gms. 3*1
Water applied, liters
5.0

20
8.2
6.8

Grass

liters
Hillsdale
Hillsdale
Hillsdale
Brookston

15
13
18
17

16
5-7
5-1

14
5-4
4.7

range cultures there was a sharp reduction of the growth
accompanied by yellowing and lack of new leaf production.
The most noticeable reduction was on the bluegrass on Brook­
ston clay loam with only 10 cm. of growth.

In contrast,

bluegrass grew 13 cm. on the Hillsdale sandy loam.

The fes­

cue grew 10 cm. in the first fourteen days and only 2 cm.
more in the last twenty days.

In the first period the great­

est growth occurred on the excess soil moisture range cult­
ures.

The greatest growth occurred on the high soil moist­

ure range cultures during the second period.

Plates 7, 8,

and 9 show the growth response of the grass to four moisture
conditions during this period.
The amount of water applied during this period was

19

Response of three grasses to the Indicated soilmoisture ranges during the second growth period
in the greenhouse, 1949.

ri r

low
medium
high
excess
Plate 7» Bentgrass on Hillsdale sandy loam soil.
Compare with Plate 4 of first growth period.

low
medium
high
excess
Plate 8. Bluegrass on Hillsdale sandy loam soil. Bluegrass
was taller, but less dense, than on Brookston soil.

low
medium
high
excess
Plate 9. Bluegrass on Brookston soil. Growth of bluegrass
reduced most by excess soil moisture.

probably the best indicator of the actual water relations in
the three series.

The excess soil moisture range cultures,

with surface evaporation, used the same amount of water as
the medium soil moisture range cultures where there was little
surface evaporation and almost complete water utilization
between each water addition.

Meanwhile, low soil moisture

range affected little economy in the amount of water used
beyond that of the medium soil moisture range.

The low range

cultures rapidly used water after each addition and a low
level of water availability was again quickly reached.

Fig­

ure 4 follows the available moisture during this period for
representative cultures of bentgrass.

Cultures under the

high range required six applications of water while those in
the medium range required only four as shown in Figure 4.
The ability of the nylon soil moisture blocks to follow
the available soil moisture at the lower ranges of avail­
ability is indicated in the low soil moisture range trends.
This is shown in the "dashed" lower line of Figure 4.

As

the grass increased in size, increased frequency of water
additions were necessary to maintain a given soil moisture
level.

For the bentgrass cultures maintained in the low soil..

moisture range there were 12, 9» and 8 days between water
applications; for the medium soil moisture range cultures
there were 11, 8, and 7 days and for the high soil moisture
range cultures there were 8, 7, 7> and 5 hays, respectively.
During this period the deepest roots in the excess
soil moisture range cultures were reduced to a depth of less

211

FIGURE 4. PER CENT OF AVAILABLE SOIL MOISTURE DURING
SECOND GROWTH PERIOD OF BENTGRASS ON
HILLSDALE SANDY LOAM SOIL. GREENHOUSE »49

SOIL MOISTURE RANGES
excess- above saturation
high o —
medium
low

140

Q
•

#—

x

O-.

120

100

\
8

\

12
16
20
24
DAYS IN SECOND GROWTH PERIOD

than two inches.

The root system was largely a surface mat

of roots with the greatest density at the edges of the cult­
ures and some roots actually extended up the side of the con­
tainers as much as a half-inch.

With no soil compaction and

a constant high level of water, always near complete sat­
uration, these surface roots enabled the grass to exist.
Third Growth Period—

During the third growth period

in the greenhouse, May 3 to June 16, a period of 44 days,
temperature and relative humidity conditions were less favor­
able.

On bright sunny days the temperature sometimes reach­

ed 100°F. and the relative humidity went as low as 15 per
cent; however, such days were relatively few.

Midway through

this growth period tissue tests, following the Spurway system
(8 ), indicated that nitrogen from the original application
of 10-6-4 at the rate of 1,500 pounds per acre was exhausted.
An application of soluble fertilizer of one gram of actual
nitrogen per culture was made.

Ammonium nitrate was dissolv­

ed in water and a dilute solution applied to prevent salt
injury to the grass.

This small water application interrupt­

ed the moisture ranges as indicated in Figure 5 by the irr­
egular moisture availability lines on the twenty-second day.
The height of the grass growth in the low soil moist­
ure range cultures reported in Table 5 s was about the same
as that for the first growth period shown in Plate 3*

Bent

was lowest, 11cm., fescue v/as medium, 14 cm., and bluegrass
was tallest, 16 cm.

However, the dry weight of the average

of three replications of each of these grasses is nearly

Table 5» Effect of four soil moisture ranges on the height
and yield of grasses during third growth period. Each
figure is an average of three replications.
Soil Moisture Ranges
High
Medium
Excess

Low

18
17
25
21

13
16
20
17

11
14
16
16

Dry Weight of Clippings, gms.
bentgrass Hillsdale
6.0
fescue Hillsdale
5-5
bluegrass Hillsdale
6.0
bluegrass Brookston
5.0

14.0
9.3
11.8
11.1

7.5
7.5
7.0
9.3

6.2
6.1
5-3
9-3

Water Applied, liters
bentgrass Hillsdale
fescue
Hillsdale
bluegrass Hillsdale
bluegrass Brookston

10.0
8.6
9,5
. 9-3

5.8
6.6
6.4
6.5

6.2
4.9
5-3
6.7

20
11.6
9.4

17
7.8
6.4

14
6.7
5.8

Grass

Soil
series

Height of Growth, cm.*
bentgrass Hillsdale
fescue
Hillsdale
bluegrass Hillsdale
bluegrass Brookston

13
10
20
12

7.9
7.2
9.1
6.5

Averages of Above Grasses & Soils
Height of growth
14
Dry weight of clippings
5.6
Water applied
7.7
the same.

In the excess soil moisture range cultures, the

addition of nitrogen midway in the growing period stimulated
new growth of a deeper green color for a short period of time.
As a result the yield of grasses in the excess

soil moisture

range for this period was much greater than in the second
period.

Plate 13 illustrates the heavy top growth produced

during this period, particularly, in the high soil moisture
range cultures.

These cultures were able to use the applied

nitrogen to the best advantage because they had a good root
system and ample moisture.

There was much less variation in

dry weights of grass produced in the medium and low soil
moisture ranges.

Higher yields from the medium and low soil

FIGURE 5. PER CENT OF AVAILABLE SOIL MOISTURE DURING
THIRD GROWTH PERIOD FOR INDIVIDUAL BENTGRASS
CULTURES.
MOISTURE RANGES
EXCESS above saturation
HIGH
0
MEDIUM •
LOW
*

160

140

120

80

60

g 40

20

12

DAYS

16

OF

GROWTH

20

24

28

52

25
moisture range cultures on the Brookston clay loam soil
indicate its greater fertility over that of the Hillsdale
sandy loam.
The amount of water applied in this growth period was
particularly affected "by the factors- of evaporation and rad­
iation mentioned by Livingston and Koketsu (15)*

High temp­

eratures and greater evaporation increased the loss of water
from the cultures receiving excess soil moisture.

In the

high soil moisture range cultures, both the moisture applied
and resulting yields show that fescue responded less to the
additional nitrogen than the other grasses.
Figure 5 shows the available moisture ranges for the
third growth period.

As in the second period, the use of

water early in this period was much less than that later in
the same period.

This is partly a result of time required

for new top growth to be initiated after the previous cutting.
During this time the decreased amount of water lost by trans­
piration was important.

The relative variations in the three

moisture ranges for this soil is well illustrated in Figure 5.
The fertilizer application on the twenty-second day and the
addition of irregular amounts of water caused flucuations in
the soil moisture readings that were corrected by the next
regular application of water.
Summary of Growth and Moisture Range Relations-- The
great reduction in the yield of each grass culture receiving
excess soil moisture after the first period is shown in
Table 6.

The totals for each .grass- show that bentgrass

yielded 87.9 grams, the fescue yielded 66.1 grams, and the

26
Table 6. Summary of the clipping yields for three growth
periods for each grass-soil condition. Each number is
an. average of three replications.
Soil Moisture Ranges
Grasses
Soil
Low
High ' Medium
Excess
series
bentgrass Hillsdale
4.4
10.7
9.4
3.1
First growth period
6 .0
7.2
8.2
Second growth period
3-3
6.2
14.0
Third growth oeriod
7.9
7,5
31.6
15.3
19.1
21.9
87-9
fescue
Hillsdale
3.4
First growth period
5-2
3.7
7.7
3-4
Second growth neriod
4.1
3.9
6.3
6.1
Third growth period
.3-5
.1:3,
20.8
12.9
15.1
17.3
66.1
bluegrass Hillsdale
First growth period
5.2
3.3
3*7
5-7
Second growth period
8.8
4.6
2.9
5-1
7.0
11.8
Third growth period
6.0
5_-I
13.2
25.8
15.8
14.6
69.4
bluegrass Brookston
First growth period
3.9
6.7
3.5
5.7
Second growth period
2.2
9.4
6.7
7.3
Third growth period
11.1
5.0
9.3
9-3
20.1
26.2
19.9
13-9
80.1
61.5
69-9
66.7 104.4
303.5
bluegrass, on the same soil, yielded 69*4 grams.

The more

vigorous growth of the bentgrass was observed in various
moisture ranges for each growth period.

In the second

growth period the fescue receiving medium and low soil moist­
ure was not watered after cutting and the beginning of new
growth was slower than for the other grasses for this period.
•Higher yields were taken from the Brookston soil in
almost every instance.

This, was particularly true in the

third growth period where the greater fertility and more,
storage of available soil moisture allowed greater grass
growth compared to the Hillsdale soil.

Root samples examined

at the close of the experiment showed that some root reduction

occurred in the high soil moisture range cultures on the
Brookston soil.

The highest yield attained from this treat­

ment was only 11.1 grams which was less than the 11.8 grams
for the Hillsdale soil in the same period.

The difference

in the total yield for bluegrass on the two soils, 10.7
grams, is attributed chiefly to the longer periods of growth
between wiltings in the low soil moisture ranges on the
Brookston soil.
The total yield for the high soil moisture range cult­
ures, 104.4 grams, was much greater than any of the other
three soil moisture range cultures.

This high series, which

fluctuated between 50 and 150 per cent available soil water,
as plotted in Figures 3, 4, and 5» supplied sufficient moist­
ure at all times and with the aid of the applied fertiliser
the cultures produced a luxuriant growth.

From the averages

in Table 7 it was found that the medium soil moisture range
cultures used only 72 per cent as much water and produced
only 67 per.cent as much growth as the grass receiving high
soil moisture.

The low soil moisture range cultures used

66 per cent as much water and produced 58 per cent as much
top growth as the high moisture series.
Table 7 gives an average of the three growth periods
as a basis for summarizing the results of the effects of
different soil moisture ranges on the growth of turf grasses
in-the greenhouse.

The height of the grass clippings re­

moved varied only slightly in the different periods for the
low, medium, and high soil moisture range cultures.

However,

excess soil moisture caused abundant growth, 22 cm., until

28
Table 7» Summary of the effect of different soil moisture
ranges for three growth periods. Each figure is an
average of 12 pots.
Growth
Soil Moisture Ranges
period__________________Excess
High Medium
Low
Height of Clippings, cm.
14
First period, March, 27 days 22
16
19
14
Second period, April,34 days 11
20
16
14
Third period, May, 43 days
14
20
17
Dry Weight of Clippings,gms.
First period
7-7
Second period
3.1
Third period
5.6
Water Applied, liters
First period
Second period
Third period

3.9
5.7
7.8

3.3
5-4
6.7

3.1
5.1
6.4

3-1
4.7
5.8

20
8.7
6,8

16
5-8
4.9

14
5-1
4.5

778

840

883

7*3
5.0
7*7

Average of three periods*
Height of Clippings
15
Dry Weight of clippings
5.5
Water applied
6.7
Pounds of water applied
per pound of dry grass

6.4
8.2
11.6
4.2
6.89.4

12H2

* Each figure average of 36 cultures.
limited by a lack of available nitrogen at the beginning of
the second growth period.

In the second period the average

height of growth was only 11 cm. for the excess soil moist­
ure range cultures.

This was much- less than the 20 cm.

growth of the grasses receiving high moisture during the
same period.

The heights and yields during the third period

growth was affected, by the nitrogen addition; they Increased
significantly above that of the second period.

On the low

soil moisture range cultures the height of growth was 14 cm.
in each period, yet the dry weight of clippings increased in
. each period over that of the.preceding one.

This would be

expected, dub to the longer period of growth, and also the

thicker development of the turf as the grasses increased in
age.
One of the purposes of this study was to determine the
most economical range of soil moisture required to secure good
turf growth.

Thus, with a continuous measurement of the soil

moisture and a record of the water applied, it was possible
to determine the amount of water used to produce a given,
yield of clipped grass.

The average yields for the high,

medium, and low soil moisture range cultures are good indi­
cators of the utilization of the water applied.

7/hen these

figures are converted to the commonly used terms of pounds
of water required for each pound of dry matter produced, the
values at the bottom of Table 7 were obtained.

These values

fall within the range of 750-1*000 given by Noer (21) as a
result of clipping trials on a putting green.

The figure

of 1,232 for the excess soil moisture range included that
lost by evaporation from the moist surface, and some two
liters of excess water left in the soil at the close of the
experiment, as well as that used by the grass.

The saving

in water by allowing the plants to wilt, as in the low soil
moisture range cultures, was not as large as expected.

The

water applied with this method was not the most efficient
in producing growth in this moisture range.

This might be

explained by the rapid uptake of water after it was applied
to the wilted cultures.

There was a definite reduction in

the daily use of water as the plants were allowed to approach
wilting.

The moisture curves in Figures 3» 4-, and 5 show a

definite break at about 20 per cent available moisture.
Theoretically, the soil moisture should be allowed to approach
this percentage before applying supplemental irrigation water
in order to obtain the greatest efficiency of the water, to
have the least amount of mowing, and yet, to maintain a satis­
factory turf.

Such a soil moisture range would allow root

extension into all the soil area possible and would encourage
the necessary aeration mentioned by Mott (19) and others.
Moisture and Nitrogen Relations
The marked influence of moisture on nutrient avail­
ability has been shown by several investigators.

Lawton (14),

for example, working on compacted soils in the greenhouse,
showed that the availability of nitrogen and potash, partic­
ularly, may be limited by a reduction in aeration or excess
moisture in the soil.
The greenhouse experiment made it possible to study
the effect of a limited nitrogen supply in two different
ways.

First, twelve check cultures were not fertilized and

were compared with those receiving fertilizer under similar
moisture conditions.

Second, some cultures that received

fertilizer were completely saturated and the effect of this
excess water on nitrogen availability noted.

Nitrogen was

applied in a soluble form and the grass response observed.
Yield of fertilized and unfertilized grasses—

The

comparison of yields of the fertilized and unfertilized
grass is given in Table 8.

During the first growth period

31
Table 8. The yields of three grasses on fertilized and un­
fertilized soils when maintained within the high soil
moisure range. Average of three replications in. the
greenhouse, 1949.
Dry weight in grams
Soil
Grass
fertilized
unfertilized
series
First Growth Period
bentgrass
Hillsdale
fescue
Hillsdale
Hillsdale
bluegrass
Brookston
bluegrass
Second Growth Period
bentgrass
Hillsdale
fescue
Hillsdale
bluegrass
Hillsdale
bluegrass
Brookston
Third Growth Period
bentgrass
Hillsdale
fescue
Hillsdale
Hillsdale
bluegrass
Brookston
bluegrass
Total of1 All Growth Periods
bentgrass
Hillsdale
Hillsdale
fescue
Hillsdale
bluegrass
Brookston
bluegrass
Pounds of water applied per
pound of1 clipped grass*
Liters of water required for
each culture*

9.4
5-2
5.2
3-7
25.5

4.4
4.2
4.3
,4.4
17.3

8.2
6.3
8.8
9.4
32.7

3.8
3.8
4.9
6.7
19.2

14.G
9.3
11.7
11.1
46.1

4.8
2.6
2.9
4.0
14.3

31.6
20.8
25.7
26.2
104.3

13.0
10.6
12.1

778

1348

20.3

17.2

50.8

* Average of 12 cultures.
the recently potted soils were able to supply some nitrogen
to the grasses and the differences in yields of 17-3 grams
for unfertilized and the 25.5 grams for the fertilized is
not as great as that in the later periods.

Tissue tests

on the leaf blades of the unfertilized grasses gave a low
nitrogen test during the first growth period.

At the

32

no fertilizer
1500 lbs./acre of 10-6-4
Plate 10. Growth of bentgrass at high soil moisture range
for both cultures during second growth period.

no fertilizer
1500 lbs./acre of 10-6-4
Plate 11. Growth of fescue at high moisture range for
second period.

"beginning of the second growth period these plants tested
"blank in nitrate nitrogen.

The greatest deficiency of nit­

rogen and the least growth occurred during the third growth
period.

The total yield of the unfertilized cultures was

les3 than one-third of that for the fertilized.

The relative

size of the grasses in Plates 10, 11, and 12 shows a contin­
uing reduction in the original soil fertility from that in­
dicated during the first growth period.
The unfertilized "bent grass, which was the most dense
of the grasses, yielded the same as other unfertilized grass­
es.

However, when bentgrass was fertilized it yielded more

than either of the other fertilized grasses.

A comparison

of the relative amounts of growth of the fertilized and un­
fertilized bentgrass is shown in Plate 10.

The Kentucky

bluegrass yielded more in the second period than any other
grasses in both the fertilized and unfertilized groups.
greater fertility of the Brookston in comparison to the

fertilized
unfertilized
Plate 12. Response of bentgrass to added nitrogen during
the third growth period.
~

The

Hillsdale soil is indicated by the data in Table 8 for blue­
grass for the second growth period.

Fescue, in both the

fertilized and the unfertilized soil had the lowest yield of
clippings of the three grasses under greenhouse conditions.
The comparison of unfertilized and fertilized cultures
in the high soil moisture range shows that it required 175
per cent more water to produce a pound of grass without than
with fertilizer.

However, only 85 per cent as much water was

required to maintain the high soil moisture range where no
added fertilizer was used.
Nitrogen availability in the excess soil moisture range—
Nitrogen deficiency also occurred in the cultures receiving
excess soil moisture.

This lack of available nitrogen began

to occur early in the second growth period and quickly became
severe.

One culture.in each of the three excess moisture range

replications was treated with a dilute solution of one gram
of sodium nitrate to test the response of the grasses to
available nitrogen under these conditions.
Tissue tests on the grass blades two days later in­
dicated that nitrogen was being taken in by the plants, as
shown by a high test for nitrates.

A greener color was

apparent in the grass four days after the application of nit­
rogen and an increased rate of growth occurred.

Table 9 shows

that the nitrogen added midway in the second period increased
the yield from 12.5 to 21.6 grams for the four grasses in a
period of 15 days.

Midway in the third growth period nitrogen

was applied to all cultures.

This gave a yield of 22.1

grams for those cultures fertilized during the third period

only and 28.4 grams for those fertilized in both the second
and third periods.
Table 9. Effect of an addition of soluble nitrogen on the
yield of grasses under excess soil moisture range conditions.
G-rasses
Second
bentgrass
fescue
bluegrass
bluegrass

Dry Weighti in Grams
No supplemental
Nitrogen
nitrogen added
added

Soil
series
Growth Period*
Hillsdale
Hillsdale
Hillsdale
Brookston

Third Growth Period**
bentgrass
Hillsdale
fescue
Hillsdale
bluegrass
Hillsdale
bluegrass
Brookston

5.7
5.6
5.7
4.6
21.6

3.5
4.1
2.9
2.2
12.5

6.9
7.0
9.5
5.0
28.4

6.0
5.1
6.0
5.0
22.1

* 1 gm. NaNO-j applied April 16, 17 days before second harvest
** 1 gm. Nitrogen, as .NHZjJvO^, applied to all cultures 22 days
before harvest.
Root growth in relation to moisture supply
The roots of the grasses receiving excess soil moist­
ure were very matted at the surface and extended only about
one inch into the soil (Plate lp)*

However, the constant

high ‘Water level and the lack of compaction with rather fre­
quent water additions allowed the root system to take up the
added soluble nitrogen.

Tissue test showed a high content

of soluble phosphorus and potassium but gave a blank in nit­
rate nitrogen prior to addition of the nitrogen fertilizer.
Two weeks after the nitrogen application, tissue tests
showed a high nitrate, a low phosphorus, and a medium pot­
assium content.
The relative extent of root growth is shown in Plate 13.

36

excess
high
medium
low
Plate 13» Hoots from bluegrass 011 Hillsdale sandy loam soil,
showing root location and block position. More rhizomes
were produced in high and medium moisture range cultures.
In contrast to the shallow roots produced under excess moist­
ure conditions, the high range cultures had roots distributed
throughout the soil.

However, they did not have as many roots

in the bottom two inches of the jars as the medium and low
moisture range cultures.

The medium moisture range had an

excellent root distribution 'with a large concentration at
the bottom of the culture.
Large white rhizomes developed in the cultures main­
tained at high and medium moisture ranges as illustrated in
Plate 13.

The low moisture range soil contained some rhi­

zomes but they were small and brownish in color.
The roots of representative cultures from each repli­
cation were partially washed from the soil at the close of
the experiment.

Complete separation of the roots from the

soil was not possible, so the roots * crowns, and attached

37
Table 10. Effect of soil moisture ranges on the weight of
roots from representative cultures at the end of the
greenhouse experiment.*
Grass
Soil series
Total V/eight in Grams
Clippings
Moisture Ranges
Roots
bentgrass
Hillsdale
18.5
excess
21.9
high
'
31*6
30.5
medium
19.2
19.1
low
14.8
15.3
85.O
87-9
fescue
Hillsdale
excess
12.6
17.3
20.8
high
27.6
medium
19.1
15.1
low
16.2
12.9
66.1
75.5
bluegrass
Hillsdale
excess
14.6
14.4
25.8
high24.8
medium
15-8
20.3
13-2
low
19.1
78.6
69 •4
bluegrass
Brookston
excess
11.6
13.9
26.2
22.2
high
medium
22.8
19.9
20.1
low
20.6
77.2
80.1
303.5
504.3
* Root weight includes crowns
soil were oven dried, weighed, and placed in a muffle furnace
at a temperature of 450°C. to determine the loss of organic
matter by ashing.

Because the ash from the roots remained

in the soil, six per cent more than that weight lost by ash­
ing was considered as the weight of the roots.
Pinch and Allison (22) found that roots of undipped
sudan grass averaged one-third of the total plant weight
at three different stages of harvest.

In the present exper­

iment, with three monthly clippings, the weight of roots
was about the same as the weight of tops.

Bentgrass produced

greatest weight of roots and also of clippings.

The high

soil moisture range cultures yielded the highest weight of
roots, 30.5 grams, of any cultures.

Although the low soil

moisture range cultures had a good distribution of roots,
their weight was only 14.8 grams, about half that of the
high soil moisture range.
In earlier sections, it was shown that the limited
available nutrients in the soil that was unfertilized great­
ly reduced yields of clippings and, to a lesser extent, the
water required for growth.

The weights of roots of cultures

from fertilized and unfertilized soil are listed in Table 11.
Table 11. Effect of fertilizer on weight of roots in the
high moisture range. Each number represents one culture.
Soil
Total dry weight in grams
Grass
series
fertilized
unfertilized
Hillsdale
bentgrass
19-6
30.5
22.1
fescue
27.6
Hillsdale
Hillsdale
24.8
bluegrass
19.7
Brookston
22.2*
bluegrass
11.1*
105.1
72.5
* Roots were pruned due to lack of aeration.
In every case the cultures grown in unfertilized soil had
a smaller root system.

The high soil moisture caused a re­

duction in the roots in the cultures growing in Brookston
soil and the lower portion of the soil was essentially free
of roots.

The weight of the roots, 72.5 grams, from the

cultures receiving no fertilizer was considerably greater
than that of the tops, 50.8 grams.

In the fertilized cul­

tures the weight of the tops for three cuttings, 104.3 grams,
was almost equal to that of the root weight, 105.1 grams.

39

FIGURE 6. RELATION OF ROOT PENETRATION TO TOP GROWTH
FOR CREEPING RED FESCUE ON HILLSDALE SANDY
■LOAM SOIL

20
HEIGHT
CM.

10

4

8

12

DAYS

16
AFTER

20
PLANTING

24

28.

40
Root-top ratios of seedlings
An experiment was set up in the greenhouse to determine
the relative root-top growth of seedlings of Creeping Red
fescue when grown in thirteen inch glass pots on fertilized
Hillsdale sandy loam soil.

Nylon and plaster of paris blocks

were placed on edge, two inches from the top and two inches
from the bottom of the soil.

Masking tape held heavy brown

paper around the jars except during the time of the daily
root growth observations.

Root penetration was uniform

throughout the soil since the soil was loose and sandy.

A

wax pencil was used to mark the daily advance of the roots.
These data are plotted in Figure 6.

The growth in root

length exceeded that of the tops at all times.

Twenty days

after germination, the roots had extended to the bottom of
the pot, 24 cm., for an average growth rate of 1.2 cm. per
day.

In the same time the tops had grown only 13 cm. for

an average of .65 cm. per day.

However, the dry weight of

the tops above soil level averaged 4.7 grams while the roots
averaged 4.1 grams two months after germination.
The expansion of the root system was also followed by
changes in the moisture block readings.

Bouyoucos (4) had

shown that there is little moisture movement in the lower
ranges of available soil moisture.

Moisture absorption by

the roots was indicated by changes in the block readings
only when the roots were within an inch of the soil moist­
ure blocks.

At that time the soil was at field capacity and

some moisture movement toward the roots could take place.

41
The upper soil moisture block indicated a geater re­
moval of moisture in all five periods.

This was particularly

true during the earlier growth when the roots had not reached
the lower block area.

As the root system expanded, less

variation was noted between the reading of the lower and upper
blocks.

At the end of two months growth, the lower soil

moisture blocks indicated less than 10 per cent more in the
lower part.of the soil column than in the upper.

From this

experiment it was concluded that one block placed midway in
the soil column was an adequate measure of soil moisture
conditions.

42
FIELD EXPERIMENTS
Methods
The turf plots were located on Hillsdale sandy loam
soil at the College River Farm, two miles southeast of
Okemos, Michigan.

Below the twelve inch surface layer of

this brownish sandy loam was a fourteen inch layer of yellow­
ish sandy loam which was an open leached layer.
years the area had been in grass.

For several

It was fall plowed in

1947 and cultivated twice in 1948 prior to the preparation
of the experimental plots.

In September 1948 an area 36 by

180 feet was plowed, harrowed, and hand raked several times
to remove the gravel and stones and to level the area.
Fifteen pounds of 10-6-4 fertilizer and five pounds
of lead arsenate were applied broadcast to each 1,000 square
feet and raked prior to seeding.

On September 13, 1948

Creeping Red fescue (Festuca rubra) and Kentucky bluegrass
(Poa pratensis)

were seeded 011 parallel strips, 18 by 180

feet, at the rate of one and one-half pounds seed per 1,000
square feet.

Germination was rapid and growth reached app­

roximately two inches during the mild and late fall.
Fifteen pounds of 10-6-4 and one additional pound of
seed were applied per 1,000 square feet on April 10, 1949*
On May 24, 2,4-D, as an ester in oil, was applied at the
rate of one and one-half j^ounds per acre.

Until July 1 both

grasses were mowed only eight times, so that a good root
system and top growth was secured before the differential
moisture and cutting treatments were begun July 1.

43

Plate 14. Illustration of block locations and the instrument
used for reading block resistances. Paper arrows show
block- locations at four inch depth for three cutting
heights and string indicate wire leads going to central
post where clamps connect the meter for readings. Strings
in background delineate different moisture range plots.
Bouyoucos nylon soil moisture blocks were placed in
sixty, 6 by 18 feet plots at a four inch depth.

These were

installed by using s. cup cutter to remove soil to a depth
of about five inches.

The soil surrounding the block was

cleared of stones and large gravel and the block packed into
position, then the cup of grass was replaced and pressed
into position.

In ten plots, additional soil moisture blocks

were placed at a ten-inch depth immediately below the four
inch block for comparison with the upper portion of the same
soil layer.

Plate 14 illustrates how the six foot wire

leads radiated from a central post to the three blocks
located under the grass plots cut at different heights;

^

Plate 15. Turf plots showing fescue on right and bluegrass
on the left half. The nonirrigated plot is delineated
in foreground by string while sprinklers are in operation
on the excess watered plots.
thus several blocks were read at one position and the blocks
and posts did not interfere with mowing.
Each plot was 18 feet long, east and west, and the
three heights of cut, one-half, one, and one and one-half
inches, ’were varied in this direction.

The irrigations ’
were

applied north and south, thus six plots ’
were watered by one
sprinkler unit.

Five Nelson square sprinklers, each of ’
which

gave an 18 by 18 foot coverage at twenty pounds pressure,
were mounted nine feet apart on a one-half inch galvanised
pipe so that a complete overlap of spray was secured.

Plate

15 gives a west to east view of the plots with the fescue
on the right.
Two replications of five soil moisture ranges were

45
maintained.

The plots which were maintained at a Hvery

high" soil moisture level, plots 5 and 8, received twenty,
three-fourths inch irrigations plus twenty rains, each of
which was more than one-third inch, during the three months
period from July 1 to October 1, 1949*

These frequent moist­

ure additions maintained the soil at near field capacity.
From July 26 to August 25, the soil averaged 106 per cent
available moisture.

It was not possible in this sandy loam

soil to produce poor aeration by excess irrigation due to
fast infilteration.

In order to avoid leaching light irr­

igations were made.
The plots in which a "high" soil moisture range was
maintained received four one-inch irrigations each of ’which
was applied when the blocks indicated a reduction in the
available soil moisture to near 50 per cent.

Such a pro­

cedure is recommended by Bouyoucos (3, 7) for shallow root­
ed field crops on sandy loam soils.

The average available

soil moisture for this range during a measured period was
78 per cent.
The plots maintained in the "medium" soil moisture
range received two, 2-inch irrigations which were applied
when the. soil moisture blocks indicated a depletion, to
about 20 per cent, of the available soil moisture in the
surface layer.

These applications kept the grass growing

and the dryness of the soil permitted a large application
of water to be retained in the soil.

The average available

soil moiture for this period was 59 per cent.

46
Two 0.75-inch irrigations were sufficient to keep the
plots within the "low" soil moisture range.

These additions

were made when the soil moisture at the four-inch depth in­
dicated that the available soil moisture approached zero,
and when the grass was Just beginning to wilt.

This timing

of applications kept the grass growing, yet slowed it down
so that it was not vigorous.

The small water application

to a dry soil, moistened only the upper part of the profile
as indicated by the ten-inch moisture block.
The plots, which were maintained in the "very low"
soil moisture range, received no supplemental irrigation.
The relation of the soil moisture ranges to the number,
frequency and rate of irrigations, and the amount of water
applied is given in Table 12.
Table 12. Relative soil moisture ranges on the turf plots
for the 1949 growth period.
Soil
fo available.
Irrigation applied
Inches of
moisture moist, for
water app.
ranges____ Jul.26-Aug.25** Number Inches Total in 5 mo.
very high
106
20
.75
15
25.6
high
78
4
1.0
4
12.6
medium
2
2.0
4
12.6
59
low
2 '
.75
1.5
10.1
59
very low
11
0
.0
0
8 .6**
* Period during the ses.son when moisture was controlled by
irrigation
■jHt Total rainfall in six months, 18.86 inches, was more than
normal and well distributed.

Results and Discussion
Soil moisture conditions
Seasonal conditions during irrigation period—

In a

one season irrigation experiment the influence of weather
assumes great proportions.

However, the comparison of this

season with that normally expected permits an interpretation
of the data secured for other seasons.
for the year was

The total rainfall

inches, 110 per cent of normal.

July,

August and September had slightly more than normal rain­
fall with very good distribution.

The rainfall scale on

the base of the soil moisture charts, Figures 7 to 11 give
the actual time and amount of rainfall represented by open
bar lines.

In April, temperatures were above normal and the

low rainfall favored early season growth.

Then a heavy

June rainfall delayed the beginning of irrigation on the
plots and made ample moisture available until mid-July.
During August, ending about August 5 and 25, there were two
dry spells that depleted the soil moisture in unirrigated
plots and allowed controlled moisture ranges.

In early

September several series of cool cloudy days and light
precipitations cut the irrigation season short.

The charts

for the high, medium, and low soil moisture present at
the beginning of September in those plots was sufficient,
when aided by the cool weather and light rains, to main­
tain the desired soil moisture ranges to the end of the
growing season without further irrigation.

Soil moisture ranges—

Figures 7 to 11 are records

of the available soil moisture data for five individual
plots which represent the conditions in all plots receiving
similar irrigation treatment.
Figure 7 gives the range of available soil moisture
at the ten-inch depth for plots maintained in both the verylow and very high soil moisture ranges.

The dotted line

representing the very low soil moisture range goes below
zero per cent available soil moisture at two periods.

After

each of these periods, the first rainfall was insufficient
to move moisture in. large amounts through the dry upper
layers and into the ten-inch soil layer.

Then the second

addition of rain increased the soil moisture content suff­
iciently for movement to occur into the ten-inch soil zone.
Under the very high soil moisture range conditions
the soil at the ten-inch depth was slower returning to
field capacity than, that at the four-inch depth.

This is

indicated by a higher per cent available soil moisture shown
as the base of the very high soil moisture line for the
ten-inch layer.
The excess water during and at the close of irrigation
was well above 100 per cent.

However, readings from the

blocks at hourly intervals following irrigation showed that
the soil permitted the excess water to pass downward readily
and the sandy soil was again near field capacity after three
hours.

The field capacity was not completely reached until

approximately one day after irrigation at the four-inch

I

\

VERY HIGH

INCH
PER CENT AVAILABLE SOIL MOISTURE
FIGURE
DEPTH FOR VERY HIGH AND VERY LOW SOIL. MOISTURE RANGES,

VERY

t-0 sn

L n h
i u l

y

? AU6
PERIOD OF IRRIGATION

VO

.SEPT

zone while in the ten-inch zone more time was required.
Thus, the slope of the per cent available soil moisture
curve is very steep on the drying cycle from the time of
irrigation until the field capacity was approached, then
the curve levels off as the excess moisture is removed.
After this short leveling period, a rather uniform downward
gradient was found as the per cent available soil moisture
decreases from 100 toward 20 per cent.

At slightly below

20 per cent, the plant was less able to withdraw moisture
from the soil and the slope again levels off as zero is app­
roached as was shown in the moisture curves of the green­
house experiments and was indicated also in the unirrigated
plots in the field.
The increased conductivity as determined by the nylon
blocks, due to the addition of chemical fertilizers on Aug­
ust 11 and 23, reached a peak on August 17 and again on
September 6.

Removal of the fertilizer salts by leaching,

under excess irrigation, was relatively rapid.

In other

plots, not excessively irrigated, the removal of the salts
was much slower.
In Figure 8 the available moisture at the four-inch
depth for the very high and very low soil moisture ranges
is shown.

Here the nearness to the surface is indicated

by the greater variation of the high and low points on the
available soil moisture lines.

The light rains on the un­

irrigated soil were sufficient to cause an increase in the
soil moisture content at the four-inch depth although a

FIGURE 8• PER CENT AVAILABLE SOIL MOISTURE AT FOUR INCH\DEPTH FOR THE VERY HIGH
AND VERY LOW RANGES. RIVER FARM, 1949.
'i

V.ERY HIGH
uJ loo

INCHES

RR1NFRUL

VERY LOW

8

JULY

“

fius
PERIOD OF IRRI6RT10N IN m<?

10 SEPT

ui
H
i

52

dry condition was soon re-established.
Figure 9 shows that four irrigations were sufficient
to maintain the soil above a minimum, approximately 50 per
cent, available soil moisture during July and August, with
an average of 78 per cent available during that period.

In

September, cooler weather and eight rains kept the soil at
a relatively high soil moisture content and no irrigations
were required.

Here the fertilizer salts were gradually

moved downward, slower than in the plots, which were main­
tained in the very high soil moisture range, and the teninch block in this plot indicated that the salts were not
leached below that zone.
The soil moisture blocks were read during the summer
only as a means of determining when to irrigate the plots
to keep them within the desired soil moisture range and
determine how deep the water penetrated into the soil.
However, in Figure 10, which is an example of the plots
which were maintained in the medium soil moisture range,
the height of the upper points of the lines illustrates
the wide variation occurring in the soil moisture.

A min­

imum of shout 20 per cent available soil moisture was reach­
ed on two occasions.

Two heavy irrigations of two inches

each on the dry soil were able to supply water throughout
the soil column to a depth of at least 10 inches, and with
following rains, to give a more lasting-moisture increase
where only small additions were made.

In the plots of

medium soil moisture, the fertilizer aalts from both the
August 13 and 23 applications were concentrated in the

T‘
t
(

FIGURE '9 • PER CENT AVAILABLE SOIL MOISTURE,
RAINFALL, TIME AND AMOUNT OF IRRIGATIONS
AS AN EXAMPLE OF HIGH 'SOIL MOISTURE RANGE.

1
i

\

i
\
#

VI
•

I

wc

A
\

too

fv
too

-h< I
ii
I
I
$

75

t
i'ii
11
•*
11

J50

it
•i
i\
i»

\

A

I

i

I

I
1
I
I
I

«

9
\
\
\

\

'I
\

I

:

\

L

is

i
.•
1.5

10

T

7T

sr

JLlL

1 iTh

I

PERIOD

is

/7

of

IRA I 6A T 10H

IN

iT-n

v

.s

RAINFALL

i
I
i
i

tiACHES

SOIL

VA

PERCENT

AMI LABI f

I

#

i« I
_(— i- -I__
■ *

i.

I*

lo Sept it

30

K

lYIO/iTURE

«

I

—

4— Inch block area.

Here the salt effect was noted until

the last of September.
The value of small amounts of irrigation, water applied
at critical times is well illustrated in Figure 11.

Here,

two small, three-fourths inch, irrigations applied when the
grass had just begun to wilt,

prevented the grass

from be­

coming dormant and carried it through until light fa,ll rains
could maintain the turf.

Although these irrigations pre­

ceded rains by only a few days, the protection of the grass
from drought damage preceding the rains produced a much
better turf during the season.

When the light fall rains

began, the grass in the plots

with very

recovered very slowly because

a drought condition had been

established.

low

soil moisture

Thus correct timing of the irrigation becomes

very important if a minimum amount of water is to be applied
during a season.

In the plots with the low soil moisture,

the light irrigations did not leach out the salts.
Generally, the soil in the low moisture range plots
was drier at the ten-inch depth than at the four-inch depth
since the small irrigations and.rains would wet only the
upper area.

Such a soil moisture condition is often critical.

If moisture is not applied when the upper layer is depleted
the turf will rapidly become dormant because it does not
have a moisture reserve in the sub-soil layers.

In contrast,

the two heavy irrigations applied to the plots maintained
in the medium soil moisture range gave a renewed subsoil
supply that supported the grass for a much longer time and
was depleted less rapidly.

INGHES

1.0

R AINFALL

so

PERCENT

AVAILABLE

SOIL

M O ISTU R E

FIGURE 10. THREE MONTHS TREND IN THE AVAILABLE
SOIL MOISTURE AS AN EXAMPLE OF THE MEDIUM
SOIL MOISTURE RANGE.

n

9 Jul

'

* fW

PERIOD

OF

to

"

IR R IG A TIO N

IN

30

VJl
VJI

56

Yield of clippings
The yields were taken from the sixty field plots
during a period of twenty days.
August 16, 22, 26, and 31*

The harvesting dates were

Clippings were taken on those

days when changes in fertility or moisture levels were made.
A hand mower with a close fitting apron was used to collect
the clippings from the entire plot.
weights were obtained.

The green and oven dry

Four successive yields were taken

from each plot to allow for variations in the mower settings
and changes within each soil moisture range.
Tables 1 and 2 of the Appendix give the individual
plot yields for the four cuttings.

Table 13 is a summary

of data for the five soil moisture ranges.

Each figure re­

present the total yield of six plots.
After the clipping of August 11, all plots were fert­
ilized with fifteen pounds of 10-6-4 per 1,000 square feet.
A one-half inch rain fell shortly after this fertilizer
treatment.

The bluegrass yielded 4,085 grams dry weight at

the next clipping whereas, the fescue yielded only 2,291
grams.

During the following periods the yield of fescue

was about three-fourths that of bluegrass.
From August 16. to 22 the soil continued to dry out
and yields from the plots showed a definite relationship
to the available soil moisture.

Yields were reduced on the

unirrigated areas and the moisture in. the green clippings
decreased to 55 per cent.

The grasses from the irrigated

areas contained about 80 per cent moisture and the dry

4

/ *

FIGURE 1 1 . THE THREE MONTHS TREND IN THE AVAILABLE SOIL MOISTURE AT FOUR INCH
DEPTH OF THE LOW SOIL MOISTURE RANGE UNDER HIGH CUT FESCUE, PLOT 5 .

I&o

I'*

i i\ ;\i\

'is' i

\

r e a d in g s

I
I

1i

so­

•
!
'

\ ! \

4

'! > 1
M l ,
*
'
\

*»
\

vl

ls

1 '

' 1 \
11
V
'i
\

LIME REPRESENTS
APPROX. AVAIL SOIL MOISTURE

fx

1
1
1
1
\
\
\
1
•
*
I
t%
\

T
V
\
•
1

!\

U 'A

t-5
tw o

%r

to

IR R IG A T IO N S

/
S

JLJL
I

1

1

JTwk

16

PERIOD OF

17

as

|RR|6ATI0II\

IN

AU6-

[1[Th Hn
m9

le

SEPT.

1$

RAINFALL

AVAILABLE

rt
i,
•»
!«

'
1
'

\

INCHES

m-BIOCK

\
%

R

PERCENT

\

30

iq

SOIL M A T U R E

IP*

Table 13. Summary of the yield of clippings from the turf
plots as affected by available soil moisture ranges.*
Available soil
Dates of harvest in August
moisture range
16____ 22________ 26_____ 31_____ Total
Creeping ned Fescue
285
1016
very low
298
160
273
i860
362
low
500
607
391
601
medium
658
4-37
859
2555
612
hi gh
566
936
3019
905
very high
628
982
3232
976
646
11,682
Total by dates
2410
3318
2291
3663
very low
low
medium
high
very high
Totals by dates

327
783
786
970
1219
4085

341
750
785
1265
1251
4492

Kentucky bluegrass
146
355
784
515
784
1067
806
1128
937
1155
3188
4489

1169
2835
3412
4169
4662
16,244

* Each figure is the sum of six plots; individual plot
yields are given in Tables 1 and 2 in Appendix.
weight yields increased over that of the preceding clipping.
The clippings on August 26 were taken during a very dry
period.

The low yield of clippings for the unirrigated

turf was due to the lack of available soil moisture through­
out the root zone.

During this time the unirrigated grass

turned brown and the green clippings had a high percentage
of dry matter.
Following the clipping on August 26, tissue tests in­
dicated that insufficient nitrogen was available.

An app­

lication of five pounds of ammonium sulfate per 1,000 square
feet was applied at this time.

The plots were then watered,

(Note soil moisture range charts, Figures 7 to 11.)

The

grasses responded favorably to the application of nitrogen
and also to the high available soil moisture as they did
during the first and second periods.

Although fescue

yields increased more on a percentage basis than the bluegrass
its total yield was only about three-fourths that of the blue­
grass.
The progressively greater yield for each Increase in
available soil moisture illustrates that, on this very open
soil, excess application of moisture was not detrimental.
The greenhouse experiment showed also that larger yields
are obtained under a high percentage of available soil moist­
ure.

However, the yield of the grass under the medium soil

moisture range conditions appeared as satisfactory as that
of a higher soil moisture.

This is significant in consider­

ing the economic aspects of turf maintenance.
Turf ratings
Three monthly ratings of the turf were made after
the soil moisture ranges and cutting heights had been main­
tained for forty-five days.

They were rated 1 to 10, with

10 considered a perfect turf and 1 very poor.

Factors

considered in the rating values were: uniformity of cover,
golf ball supporting ability, freedom from weeds and clover,
and general appearance of the turf.

Nonirrigated fescue

turf as shown in Plate 16, when cut at one-inch height was
given a rating of 4 in October while that cut at one and
one-half inches was rated as 6.

The nonirrigated fescue

turf cut at one-inch height had many small bare spots be­
tween the crowns of the fescue.

These spots are undesir­

able for the lie of golf balls.

The Irrigated turf, shown

in Plate 17, was given a rating of 10 because it gave good

60

one and one-half inch, cut
one inch cut
Plate 16. Nonirrigated fescue after fall growth began. White
sand placed in bare spots show bunched growth*

Plate 17* One and a half inch cut fescue in irrigated plots
Note dense ground cover.
ground cover, was free of-weeds, and supported golf balls
at a uniform height above the ground.
Table 14 summarizes the turf ratings of the plots as
affected by five soil moisture ranges.

As the soil moisture

increased the turf ratings increased.

In August the various

soil moisture conditions caused little variation in the turf
ratings as only one dry period had occurred.

During Septem­

ber the ratings of the nonirrigated turf decreased to about

61
Table 15. Average of turf plot ratings as affected by the
three heights of cut in 1949.*
Averages
Dates of ratings
Height of cut
inches
Aupc.15
Sept. 17
Oct. 2
Creeping Red Fescue
3.2
one-half
4.8
2.0
2.8
6.2
one
6.4
5*6
6.6
8.4
one and one-half
8.6
8.1
8.5
average for dates
6.0
6.6
5*2
6.0
one-half
one
one and one-half
average for dates

5-9
7.3
8.5
7.2

Kentucky bluegrass
3.2
5-6
6.4
7.9
7.2
8.2
5-6
7.2

4.9
7.2
8.0
6.7

* Individual plot ratings given in Table 3 Appendix.
one-half that of the August ratings.

The turf ratings de­

creased only 20 per cent on. plots with low soil moisture.
The September turf rating on the three plots averaging above
50 per cent available soil moisture was only 10 per cent less
than in August.
By October the fall rains and the additional fertiliza­
tion had caused new growth in the nonirrigated plots as in­
dicated by the higher ratings.

Fall growth of the bluegrass

turf showed more improvement than fescue turf for all moist­
ure ranges in October.
V/ithin the different soil moisture ranges various
heights of cut caused large variations in ratings.

In Table

15 the low-cut fescue ratings averaged only 2.8 in October
while the low-cut bluegrass averaged 5.6, or twice that of
the fescue.

The bluegrass turf, cut at a one-inch height,

rated better than the fescue of the same height.

The high-

cut fescue was superior to bluegrass cut at the same height,
tfithin tne high—cut fescue turf there was little difference

62
in the ratings of turf on plots maintained in the high,
and very high soil moisture range as shown in Figure 14.
From these ratings the turf of the medium-cut bluegrass and
the high-cut fescue appear outstanding.
Composition of the turf
Considerable use of the per cent composition method
for measuring turf has been made by Welton (26) and Musser
(20) in following changes in turf conditions after fertiliz­
ation.

The effects on turf of varying soil moisture and

cutting heights was measured in this study by estimating
the per cent of bare ground, clover, weeds, and grass.

A

square foot grid, divided by fine wire into 100 divisions,
was placed at several positions on.the turf of different
plots and the percentages estimated by observing the area
under the grid.

Individual turf plot percentages are given

in Tables 4 and 5 of the Appendix and are summarized in
Tables 16 and 17 •
Each Increase in available soil moisture gave a re­
duction in the bare ground percentages as shown in Table 16.
The turf on plots of the very low soil moisture range had
an average of 30 per cent bare ground on September 17.

Turf

on plots in the very high soil moisture range averaged only
7 per cent bare ground.

The turf on plots of the low soil

moisture range did not become dormant.

However, the per­

centage of bare ground was uniformly more in these plots
than on. the plots receiving greater amounts of water.
October 2, the thickening of the turf and late season

By

63
Table 16. Percentage of bare ground In turf plots as affect­
ed by five soil moisture ranges during 194-9 •"*
Available soil
Dates of ratings
Oct.2
Oct.2
moisture range Sent.17
Sept.17
Kentucky bluegrass
Creeping Red Fescue
11
26
14
very low
35
low
20
14
7
15
8
12
6
medium
15
high
14
10
7
7
4.5
very high
8
9
5
* Each figure is the average of six plots. Individual
percentages are given in Table 4-, Appendix.
Table 17. Percentage of bare ground in turf plots as affect­
ed by three heights of cut during 194-9.*
Height of cut
Dates of ratings
inches
Oct .2
Oct. 2
Sept.17
Sept.17
Creeping Red fescue
Kentucky bluegrass
one-half
20.6
11.6
31.7
23.1
one
16.6
7.6
5.2
9.7
one & one-half
4.2
5.8
4.7
7.3
12.2
average for dates 18.7
7.0
11.7
* Each figure Is average of ten plots.
growth of clover* materially reduced the percentages of bare
ground as illustrated in Plate 18,
In both September and October the fescue plots had
gres.ter percentages of bare ground area than the bluegrass.
This difference is clearly shown in Table 17 which gives
the effect of three cutting heights on the percentages of
bare ground.

With both grasses the greatest percentage of

bare ground was in the low-cut areas.

The percentage of

bare ground in the high-cut grasses on plots receiving med­
ium, high and very high soil moisture averaged only 2.5
per cent for both September and October.

The medium-cut

fescue turf was more pitted with bare spots and had less
clover.

The fescue plots consistantly contained a larger

64
amount of bare ground than the corresponding bluegrass plots.
The 1949 season was favorable for white clover.

A

high June rainfall followed by irrigation in the dry periods
resulted in favorable soil moisture conditions for clover
germination' and growth#

Also this was the first year of the

turf seeding and the turf was thin.
Table 18. Percentage of clover in turf plots as affected
by the varying soil moistures during 1949**
Available soil
Dates of ratings
Oct. 2
moisture ran^e Sent.17
Oct. 2
Sent.17
Kentucky bluegrass
Creeping Red Fescue
very low
3-0
7.7
5-3
9-3
low
5.0
9-1
11.5
8.7
medium
9.8
4.1
7.0
15.3
high
6.8
9.1
16.5
7.5
very high
19.0
7-7
8.3
6.5
* Each figure is an average of six plots. Individual plot
ratings given in Table 5 of the Appendix.
Turf on the plots was practically free of clover
until after mid-summer.

By August 15 it was present in

only about one-half the plots but by September small clover
plants were present in all the plots.

As shown in Table 18,

the infestation of the fescue turf with clover appears to
have little relationship to available soil moisture in
either September or October although a slight increase
occurred by October.
On plots maintained in the very low soil moisture
range, the bluegrass turf remained more clover free than on
the Irrigated plots which had higher available soil moisture
during the time of early clover growth.

Glover was consid­

erably denser in the bluegrass than in the fescue turf dur­
ing both September and October.

In October the percentages

65
Table 19. Percentage of clover in turf plots as affected
by three heights of cutting during 194-9 •*
Height of cut
inches

Dates of ratings
Oct. 2
Oct.2
Sept.17
Sept.17
Kentucky Bluegrass
Creeping Bed. Fescue
7«9
13-6
8.6
16.5
4-.7
7-7
12.5
7.3
2.7
7.4
14.0
3.6

one-half
one
one and onehalf
average for each 5*1
date

8.2

7.9

14.3

* Each figure is the average of 10 plots.
of clover increased with increasing moisture.

Turf on the

plots receiving very high soil moisture had almost twice as
much clover as that on plots receiving a very low amount of
soil moisture.
Siace white clover grows more closely to the ground
than the grasses studies, the height of cutting thus became
a factor mainly in the amount of resistance that the remain­
ing turf could give to the clover Infestation.

Table 19

shows that the clover percentages increased with each de­
crease in the height of cutting on the fescue turf for both
months.

Between the September and October ratings, the

percentages, of clover in the high-cut fescue turf increased
very little compared to that in the low-cut.

The relative

freedom of the high-cut fescue from clover (Plate 20)was
attributed to the competition of the thick turf.
The bluegrass turf contained uniformly high percent­
ages of clover at all heights of cut.

The values were about

equal to those of the low-cut fescue turf.

It appeared that

the turf on these plots was not thick enough to afford eff­
ective competition to the clover.

The high-cut bluegrass

Plate 18. Top. One-half Inch cut, nonirrigated bluegrasa late
in the season. Composition included 25% clover and 12%
bare ground.
Plate 19* Middle. One-half inch cut, unirrigated fescue late
in season, 'tfeeds germinated during late spring; percentages
include clover 10%,, bare ground MO%, and crabgrass 5%*
Plate 20. Bottom. One and one-half inch cut irrigated fescue.
Compositioii was 95% grasses.

plots contained, an exceptionally high percentage of clover.
The greater height of mowing on these plots cut off little
of the low growing clover in the rather open bluegrass turf.
The bluegrass plots had less bare ground area than the fes­
cue plots but the situation was reversed for the amount of
clover present.

The total area of bare ground plus the area

covered by clover was nearly the same for each grass.
In. May an application of 2,4-D, as an ester in oil,
at the rate of 1.5 pounds per acre, gave a good weed kill
except on sorrel which was prevalent in the area.

Several

weeds such as narrow leaf plantain, dandelion, purslane, and
crabgrass, invaded the plots during the summer.

This was

particularly true on the irrigated and closely cut plots.
The sorrel remained in the turf plots in slight amounts all
season.

The other weeds increased to as much as 5 pet* cent

In the low-cut fescue turf which was irrigated.

Plates 18,

19 and 20 give some of the contrast in bare ground, clover,
and weeds in the turf at different cutting heights and
moisture levels.
After estimating the percentage of bare ground, clover
and weeds in the turf the remainder was considered as turf
grasses.

Percentages of grass varied from a low of 4-3 to a

high of 95*

The high-cut fescue turf that was irrigated

averaged 91 per cent turf grasses.

Since the turf plots

were planted on an area of established bluegrass, old rhi­
zomes and seed of bluegrass were in the soil and initiated
some new bluegrass growth in the plots.

In the bluegrass

this was not noticeable.

In the seeded fescue turf, however,

the appearance of the bluegrass was easily correlated with
the height of cut.

The percentages of fescue and bluegrass

in samples of clippings taken from the fescue plots were
determined.

In the high-cut'fescue clippings, 95 per cent

was fescue, in the medium-cut -80 per cent and in the lowcut only 37 per cent.
Ability of Turf to Support Golf Balls
In an attempt to find measurements of turf character­
istics other than yields, per cent composition, and visual
ratings, the height at which golf balls were held above the
soil surface was measured.

A meter stick was used having

a sliding wire that turned outward at the base so that it
could touch the top of the ball lying on the turf as ill­
ustrated in Plate 21.

Since regulation golf balls are the

same diameter it was possible to measure the top of the
ball and deduct the ball diameter to find the distance in
millimeters between the ball and the ground.

Ten. golf balls

were rolled onto the turf of each plot to secure the range
in the height of ball support.

Table 20 gives the averages

of twenty ball heights for each cuttlng-moisture condition
on September 15*
The ability of turf to support golf balls at a uniform
height and the extent of the variation in the readings was
found to be a good indication of the pockets and thin spots
in the turf in which all the distances between the ball and

69

Plate 21. Illustration of the sliding wire attached to a
meter stick to measure the height of the ball above the
ground by subtracting the ball diameter.
the soil were near the same.

In only six of the sixty

plots was this uniformity of distances obtained.

In con-

trast the range of ball support heights on many of the
plots was quite wide and the averages fail to show these ex­
tremes.

In Table 20 the averages show that ball support

of the medium-cut bluegrass is much better than the same
height of fescue turf.

The low-cut fescue turf had several

negative readings when the ball rolled into low pockets
between the crowns and was below the general ground level.
The irrigated and high cut fescue turf was again outstanding
by its uniformity of ball support.

The 14 mm. distance

between the ball and the ground was in effect an excessive
"automatic tee".

^

However, this did indicate that the turf

^

70
Table 20. Effect of three heights of cut and five soil
moisture ranges on the height, in millimeters, of
golf balls above ground. -*
Available
soil moisture
very low
low
medium
high
very high

Creeping Red fescue
Kentucky bluegras s
Height of cutting, inches
Ave.
2
2.8
0
0
4
5
5
8
10
6.0
1
0
9
7
7.2
12
10
10
7
3
1.5
2
8.0
14
9
13
7
3
12
8
7.8
1
14
9
3

* Each figure is average of twenty measurements.
was thick and uniform on these plots.

The ball support

height of the turf for a given cutting level averaged about
the same on the plots v/ith medium, high, and very high soil
moisture.

71
SUMMARY AND CONCLUSIONS
This investigation was undertaken to study by means
of greenhouse cultures and field plots, the relationship be­
tween available soil moisture, fertilizers, and height of
clipping on the yield and value of bent, bluegrass and fes­
cue turfs.
Fifteen cultures each of Astoria bent, Creeping Red
fescue and Kentucky bluegrass were grown on Hillsdale sandy
loam surface soil and fifteen cultures of bluegrass

were

grown on Brookston clay loam surface soil in the greenhouse.
Three cultures of each group were left as unfertilized
checks; within the twelve fertilized cultures four soil
moisture ranges, excess, high, medium and low were maintained
by soil moisture block control.

Three periods of growth

were harvested by cutting at one and one-fourth inches above
the soil surface.

The dry weight, height of growth, water

applied, and progressive available soil moisture for each
period were measured.
In the field investigations parallel strips of blue­
grass

and fescue were divided on July 1, 1949 and cut at

three different heights under five soil moisture ranges.
Nylon soil moisture blocks were placed at four-inch and teninch depths in the plots to record the available soil
moisture and determine when to apply supplemental water.

The

yield, rating, composition, and fairway characteristics of
the turf were determined during the growing season.
The soil moisture blocks, both nylon and plaster of

72
paris, proved adequate for determining the available soil
moisture.

In the calibration of the blocks under turf, the

roots, gravel and fertilizer present lowered the resistance
readings to less than that of the laboratory calibration
from a screened soil sample.

Soil moisture blocks located

at the top and bottom of a thirteen inch soil column showed
that one block placed midway was adequate after the roots
were established, for detemining when to apply water and
for following the soil moisture trend.
Grasses growing under greenhouse conditions of high,
150 to 50 per cent, available soil moisture produced the
highest growth, greatest yield, and required the least water
(778 units) to produce one unit of dry grass.

In contrast,

cultures in the medium, 120 to 20 per cent, available soil
moisture range produced only 66 per cent as much yield, re­
quired 72 per cent as much water and 840 units of water
unit of dry matter.

per

Allowing the grass to wilt between water

applications gave only 10 per cent less water use and yield
than that secured under non-wilting conditions.

Excess

water applications in the greenhouse resulted in severe
reduction in growth that was partially corrected by an add­
ition of soluble nitrogen.
In a seedling experiment, roots of fescue extended
24 cm.'in nineteen days after germination while the tops
grew only 13 cm.

At the end of forty days gro^/th the roots

and crowns were the same weight as the tops.

Similarly, the

weight of roots produced under different soil moisture ranges
varied directly with the top growth.

However, the proportion

73
of roots.to tops was generally greater in the low moisture
and low fertility ranges ►. Under excess moisture conditions
a mass of surface roots was produced, meanwhile roots were
pruned to less than two inches depth in the soil.

Under

medium and high soil moisture range conditions, the bluegrass
had large white rhizomes, while those under low soil moisture
range conditions were small, brown and much less active.
The unfertilized cultures in the greenhouse produced
less than half that of those fertilized, yet required 85 per
cent as much water to maintain the same soil moisture con­
ditions.

In both fertility conditions bentgrass had the high­

est yields and fescue had the least.

Cultures on unfertiliz­

ed Brookston soil gave more dry weight yield than on unfert­
ilized Hillsdale soil.
It was not possible to maintain excess soil moisture
conditions in the open sandy soil of the turf plots but by
frequent additions of small irrigations the very high soil:.,
moisture range averaged 106 per cent available soil moist­
ure.

During August there were two dry periods that allowed

five soil moisture ranges to be maintained and the compari­
son of the yield, rating and available soil moisture was
made.

The progressively greater yield for each increase in

moisture for all plots illustrates that the excess irrigat­
ion was not sufficient to reduce yields.

Yet, for economy

of maintenance, the yield of the turf on the medium soil~
moisture range plots appeared as satisfactory as that of
the higher soil moisture range plots.

74

Figure^ 12. Summary charts shewing the soil moisture ranges,
number and amount of irrigations, per cent available soil
moisture and relation to yield and ratings of turf.
Soil
Moisture
Ranges
twenty-j>/4 inch

very high
high

four- 1 inch

medium

two- 2 inch

irrigations

106
78

58

two-3/4 in.39

low
none

very low

11
100

20
40
60
'
80
Percent Available Soil Moisture

Figure 13* Comparison of the yield from high cut fescue plots
with soil moisture ranges oroduced by irrigation.
very high

1093

high

1101

946

medium
low

640
220

very low
C

1000
800
600
400
drams ^ield of Four Clippings in Twenty Days

;oo

Figure 14* Rating of the turf; average of two replications for
three uonths on the high cut fescue.( 10-very good, 1-very poor)

very high
high

9-2

medium
low
very low
0

i

9.5

9.4
7-7
'4.5
2
4
6
Numerical Rating of'Turf

10

Two small irrigations, applied at critical times, pre­
vented the turf from going dormant and provided a better turf
throughout the season, as is illustrated in the ratings of
the turf in plots which were maintained in the low soil moist­
ure range.

By use of the soil moisture blocks to determine

when the soil is low in available moisture, relatively large
applications can be applied and held in the root zone for use
by the turf.

Thus those plots receiving only two heavy irr­

igations, gave a good rating throughout the season.
Rating of the turf, from 1, low, to 10, high, were
made three times during the growing season as a visual measure­
ment of the turf.

Within a given height of cut the medium, .

high and very high soil moisture ranges had little effect on
the rating of the turf produced.

In September, nonirrigated

turf was dormant and had many open areas.
The low-cut turf had the lowest ratings due to its
Inadequate ground cover and poor ball support.

On the high-

cut plots the fescue rated superior to the bluegrass as it
was more dense, gave more uhiform ball support, and was
more nearly free from weeds and clover.

In the medium and

low-cut plots the bluegrass was superior to the fescue as
the bluegrass had smaller openings and better distribution
of turf.
Percentage composition estimates were made for three
months to determine the bare ground, clover, weeds, and
grasses.

The bluegrass turf contained uniformly high clover

percentages in October, but contained less bare ground than
the fescue turf.

In the low-cut fescue, native bluegrass

76
constituted one-half of the clippings, while in the highcut fescue the clippings were 95 per cent fescue.
Fairway characteristics as determined by the support
and position of golf balls rolled onto the turf were measured
by use of a sliding wire on a meter stick.

Excessive ball

support was obtained on the high-cut fescue, but this indicat­
es the uniformity of the turf when the soil was kept within
a desirable moisture range.

On low-cut turf the average ball

support was reduced by the low pitted turf.

On thin turf,

as in unirrigated bluegrass, the use of a higher cut to ob­
tain better ball support was of slight value as it gave
"bedded lies"; in thick turf higher cutting gave uniform
although high ball support.
From this experiment it was found that the best
growth of fpscue x^as obtained where the height of cut was
above one inch, and where sufficient moisture was applied
to prevent the grass from going dormant and developing bare
spots.

The most practical method of applying water was to

permit the soil to dry to about 20 per cent available moist­
ure and then, apply a rather large amount of water to replinish the suppljr in the entire root zone for the extended use
of the turf.

Literature Cited
1. ANDERSON, A.B.C., and EDLEFSEN, N.E. Laboratory study
of the response of 2- and 4- electrode plaster of paris
blocks as soil moisture content indicators. Soil Sci.,
53:413-428. 1942.
2. BOUYOUCOS, G.J., and MICK, A.H. An electrical resistance
method for continuous measurement of soil moisture under
field conditions. Mich. Agri. Expt. Sta. 3ul. 172. 1940.
3. ______ , ______ , Improvements in the plaster of paris
adsorption block electrical resistance method for
measuring soil moisture conditions under field cond^ iions. Soil Sci., 63:455-465. 1947.
4. ______ , Cap^lllary rise of moisture in soil under field
conditions as studied by the electrical resistance of
plaster of paris blocks. Soil Sci., 64:71-81. 1947.
5. ______ , Nylon electrical resistance unit for continuous
measurement of soil moisture in the field. Soil Sci.,
67:319-330. 1949.
6. ______ , and CRABB, G.A. JR., Measuring soil moisture by
electrical resistance. Jour. Amer. Soc. Agri. Eng.,
30:581-584. 1949.
7. ______ , A pratical soil moisture meter as a scientific
guide to irrigation pratlces. Jour. Amer. Soc. Agron.,
42:104-107. 1950.
8. COOK, R.L. , and MILLAR, G.E. Plant nutrient deficiencies.
Mich. Agr. Exp. Sta. Spec. 3ul., 353* 1949.
9. GRABER, L.F. Food reserves in relation to other factors
in limiting the growth of grasses. Plant Physiol.,
6:43-72. 1931.
10.HARRISON, 3.M. Effect of cutting and fertilizer applicat­
ion on grass development. Plant Physiol., 6:669-684. 1931.
11. HUMBERT, R.P., and GRAU, F.V. Soil and turf relationships.
U.S.G.A. Journal, Vol. II No.2:25-32. June, 1949.
12. KELLER, O.J., HUNTER, A.S., HAI3E, H.R.’, and HOBBS, G.H.
A comparison of methods of measuring soil moisture
under field conditions. Jour. Amer. Soc. Agron.,
38:759-784. 1946.
13. KUHN, A.O., andKEMP, W.B. Response of different strains
of Kentucky bluegrass to cutting. Jour. Amer. Soc.
Agron., 31:892-895- 1939.

78
14. LAWTON, K. The influnce of .soil aeration on the growth
and absorption of nutrients by corn plants. Proc.
Soil Sci. Soc. Amer., 10:263-268. 1945.
15. LIVINGSTON, B.E. and KOKETSU, R. The water supplying
power of the soil as related to the wilting of plants.
Soil Sci., 9:469-485. 1920.
16. LOUVERN, R.L. The effects of fertilization, species comp­
etition and cutting treatments on the behavior of Dallis
grass and Carpet grass. Jour. Amer. Soc. Agron.,
36:590-600. 1944.
17. MELTON, F.A. and WILSON, J.D. Water supplying power of
the soil under different species of grass and with
different rates of water application. Plant Physiol.,
6:485-493* 1931*
18. MONTEITH, J.,JR. and BENGTSON, J.W. Experiments with
fertilizers on bluegrass turf. Turf Culture, Vol.l,
No. 3:155-191. 1939.
19. MOTT, G.O. Curing the problems of soil compaction and
drainage. Golfdon, p50. July, 1949.
20. MU33ER, H.B. Effects of soil acidity and available
phosphorus on population changes in mixed Kentucky
bluegrass-bent turf. Jour. Amer. Soc. Agron.,
40:614-620. 1948.
21. NOER, O.J. Water management. Proc. Midwest Turf Conference.
p 9-14, March 1948.
22. PINCK, L.A. and ALLISON, F.E. The effect of rate of nit­
rogen application upon the weight and nitrogen content
of the roots of sudan grass. Jour. Amer. Soc. Agron.,
39:634-637. 1947.
23. SCHLEUSENER, P.E., PEIKERT, F.W. and CAROLUS, R.L.
Results of Irrigation on vegetable crops. The Quart­
erly Bui., Mich. Agr. Expt. Sta. 31:343-350. 1949.
24. SLATER, G.S. and BRYANT, J.C. Comparisons of four methods
of soil moiture measurement. Soil Sci., 61:131-155*
1946.
25. RICHARDS, L.A. and WEAVER, L.R. The sorption block
soil moisture meter and hysteresis effects related to
its operation. Jour. Amer. Soc. Agron., 35:1002-1011.
1943.

79
26. WELTON, K. Fertilization of fairways: some experimental
results. U.S.G.A. Bulletin, Vol. 13* No,6:183-199*
1933*
27* WILSON, J.D. The measurement and interpretation of the
water-supplying power of the soil with special reference
to laton grasses and some other plants. Plant Physiol.
2:386-440. 1926.

APPENDIX

80
Table 1. Yield of Clippings on 30 Kentucky bluegrass plots
on River Farm, 1949. Yield is dry weight in grams from
o dv xo IOOT/ U-LU Ub
3.Moist.R Ht. of cut
22
26
16
31 ..... Total
inches
Plot No.
Very low
207
57
90
25
1
35
0.5
114
36
10
18
1.0
50
■
7u
/*>
98
3
22
10
36
1.5
6

T
—»•
>
Low
5

10

0.5
1.0
1.5

12
75
64
327

0.51.0
1.5
0.5
1.0
1.5

43
27
31

153
155
134

113
147
195

95
100
123

155
98
88

79
109
107

96
53
48

9

7

Very High
3

8

255
132
162
174

515

1169
493
564
626

125
455
101
361
...;29 .333
784
2832

0.5
1.0
1.5

155
119
106

144
143
143

148
133
106

168
187
174

615
582
529

0.5
1.0
1.5

213
116
77

108
149
98

168
150
79

208
210
120

697
615
374

786
High
2

146

750

783
Medium
.. b~

241
231
278

95
61
76

91
68
107
341

784

785

1067

3412

0.5
1.0
1-5

206
179
155

203
248
224

157
151
124

180
200
230

746
778
733

0.5
1.0
1*5

155
144
131
970

166
192
232
1265

146
123
105

153
181
184
1128

620
640
652

0-5
1.0
1-5

240
235
176

208
228
261

179
171
125

190
208
201

817
842
763

0.5
1.0
1.5

250
179
139
1219

225
196
233
1351

182
168
112
937

200
857
734
191
165
649
4662
1155

Totals by dates
Totals by height

4085
0.5— 5748

806

4169

4492
3188
4489 16,244
1.0— 5461
1 .5--5035

81
Table 2. Yield of Clippings on 30 Creeping Red fescue plots
on River Farm in 1949. Yield is dry weight in grams from
S. Moist. R.
Plot No.

Ht.of cut
inches 16

22

26

31 .. .

Total

H

o

fe

6

0.5
1.0
1.5

91
36
41

69
40
45

56
19
13

89
40
38

305
135
137

1

0.5
1.0
1.5

76
27
27
298

69
26
24
273

53
11
8
. 160

69
25
24
285

267
89
83
1016

5

0.5
1.0
1.5

82
62
53

10

0.5
1.0
1.5

60
55
J 2&
362

54
86
_26
500

65
34
108
71
_§5.
_£7
607
391

0.5
1.0
1.5

106
75
66

91
113
160

87
142
124

144
166
171

428
496
521

0.5
1.0
1.5

68
67

58
112
124
658

51
100
97

85
144
149

262
423
425
2555

1.5

106
87
84 ■

110
139
182

82
96
113

128
147
164

426
469
543

0.5
1.0
1.5

120
98
71

122
152
200
905

88
119
114

151
173
173
936

481
542
558
3019

0.5
1.0
1.5

127
130
78

127
164
221

94
124
123

169
185
157

517
603
579

0.5
1.0
1.5

107
108
78
628.

110
188
172
982

85
120
100
646

132
169
164
976

434
585
314
3232

2410

3663

11,682

Low

Medium
~ T

9

68
91
105

437

110
126
113

67
81
81

601

327
360
352

859

213
320
288
1860

High
2

0.5
1.0

7

Very Hiph3

8

Totals by dates
Totals by heights

566

2291
0.5— 3660

3318

612

1.0— ■4022

1.5— 4000

82
Table 3. , Comparative ratings of individual turf plots for three
Soil Moist.Ranges
plot
month of
nos.
rating;
Very low
1
Aug.
Sept.
Oct.

Kentucky bluegrass
Creeping Red fescue
Height of cutting, inches
1.0
total
1.0
1.5
0.5 total
0.5
1-5
5
1
2

5
2
4

7
3
6

17
6
12 35

8
4
7

7
3
6

6
1
4

19
8
17 44

Aug.
Sept.
Oct.

5
1
3

6
3
7

9
6
7

20
10
17 47
m 2

9
7
8

8
5
8

5
2
4

22
14
20_5£
100

Aug.
Sept.
Oct..

4
3
2

6
7
5

8
9
8

18
19
15 52

9
8
9

7
7
9

5
3
5

21
18
23 62

Aug.
Sept.
Oct.

4
1
2

7
5
5

9
6
6

20
12
13

8
6
7

7
6
8

6
2
5

21
14
20 55
117

Medium
Aug.
Sept.
Oct.

5
3
3

7
7
7

9
10
10

21
20
20 61

8
8
8

7
7
8

5
3
5

20
10
21 59

Aug.
Sept.
Oct.

4
1
3

6
4
7

9
9
9

19
14
19 52
113

8
7
8

7
7
8

6
4
7

21
18
23 62
121

Aug.
Sept.
Oct.

6
2
3

7
6
8

8
9
9

21
17
20 58

9
8
9

8
6
8

6
3
7

23
17
24 64

Aug.
Sept.
Oct.

5
2
3

7
8
8

9
10
10

21
20
21 62
120

9
8
9

8
8
8

7
3
5

24
19
22 65
129

Very high
Aug.
Sept,
Oct.

5
3
4

6
8
8

9
10
10

20
21
22 63

8
8
7

6
7
7

6
5
6

20
20
20 60

Aug.
Sept.
Oct.

5
3
3

7
6
7

9
9
10

21
18
20_52.
122

9
8
9

8
8
9

7
6
8

24
22
26 72
132

48
20
28

64
56
66

85
72
82

186>

73
64
79
216

59
32
56

96

86
81
85
252

6

Low

10

7

3

8

97

Total
Aug.
Sept,
Oct.

534 239

147

599

Table 4. Percentage of bare ground In individual turf plots
a3 affected by varying soil moisture and heigh. of cutting.
—
^
-• -•----->T
«
Creeping
Red -»
fescue
Kentucky vbluegrass
S. Moist. R.
Height of cutting, inches
totals
1.0
0.5
1.0
1.5
totals
Plot No.
September 17
30

.1
6

30
35

40
40

30
15

120
90
210

25
8

10

45
40

5
10

30
45

10
15

8
9

48
_££
117

5
4

5
7

27
40

37
._S1
@8

20
45

8
16

1
3

29
64
T f

2

5
3

22

29

15

22

Low

Medium
4.
9
High
... 2
7

32
25

15 .
9

5
1

52

4

100

58
"T58'

51
4

6

3

13
13

23

1

3

2

4
3

8
8

15

“ 55

"78

23I

6

12

7

9
5

2
6

4

12

8

14

18
28
“58

4
5

12
6

20

-3?
Very High
3
8

14
25

5
8

317

168

0
1
__
73

19
^4_
53
586“

October 2
Very low
1
6

30
12

18
10

7
8

55
- i

Low
5
10
Medium
A
9
High
2
7

12
30

10
14

15
28

5
14

25
20

6
12

28
-§ §

5
8

2
6
2
1

2

32
29

4
3

“81

Very high
3

14

5

2

4

22
48
70

21

27

25

33
4
4

10

18

15

22

To
15

Table 5. Percentage of clover In turf plots as greeted byfive soil moisture ranges and three heights of cutting
during 1949*________ ;
................
— ______________
S.-Moist.R.
Creeping Red fescue
Kentucky bluegrass
Height of cutting, Inches
Plot No.
0.5
1.0
1.5 totals
1.5
1.0 ' 0»5
totals
September 17
Very low
6
i
0
0
2
5
1
3
5
26
10
0
9
7
10
6
3
32
41
Low
10
8
2
25
7
10
17
5
5
8
12
10
2
1
10
10
-12
55
30
Medium
12
12
34
10
2
18
" " T
9
7
8
8
1
1
9
25
9
5
59
25
High
12
24
2
5
7
3
13
5
5
21
12
4
8
28
10
10
5
7
“4T
45
Very High
24
6
18
8
9
9
5
5
3
22
10
21
8
10
7
5
6
5
46
39
“B5
“77
"7*
“27
"79
^37
153
October 2
Very low
1
6

4
30

6

5

0
1

2
16*

2
13

8
15

12
44
-55

37
JL5
52

14
12

11
14

12
6

37

37

25
10

14
9

25
9

64
28
92

9
46
55

15
25

20
12

15
12

50

26
24
50

20
26

18
12

30
8

165

125

I4o

10
-8

Low
25
9

9
4

Medium
."“"4“
9

15
2

16
2

High
2
7

4
25

5
10

Very high
3
8

3
2
6
1

-f

“42
4
13

1
8

12
10

7
7

7
7

TOE

“73

“3S

99
68
46
114

430
"245 .
* Plot was lower and received some run off from other plots.