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W. B. (William Barbour) Nevens.

Improving bluegrass pastures : review of an early experiment on the effects of frequency of harvest, disking, application of barnyard manure on yields and protein content online

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IARY AT URBANA-CHAMPAIGN




L161 O-1096



Improving

BLUEGRASS
PASTURES



Review of an early experiment
on the effects of

Frequency of harvest
Disking

Application of barnyard manure
on yields and protein content



By W. B. NEVENS
Chief in Dairy Cattle Feeding



Bulletin 504

UNIVERSITY OF ILLINOIS
AGRICULTURAL EXPERIMENT STATION




Fig. 1. Experimental bluegrass plots. These plots were one by four rods
in area. Grass was harvested by means of a lawn mower with grass-catcher
attachment.



CONTENTS

Page Page

Three Management Practices Tested 215 Manuring Increased Both Yield and Protein. . .220

Frequent Harvesting Reduced Yield 216 Bluegrass Thrived With Heavy Rainfall 221

Disking Increased Yield 218 Reliability of Results 223

Summary and Conclusions 224



The investigation reported in this bulletin was carried out
many years ago. W. J. Fraser, now Chief in Dairy Farming,
Emeritus, was in charge of the investigation ; J. M. Barn-
hart, Assistant in Dairy Chemistry, made the chemical analy-
ses ; and H. E. Crouch was responsible for the field work
consisting of plot treatment, harvesting, etc. The tabular
arrangement of the data, the charts, and the discussion were
prepared by the author after consultation with W. J. Fraser.



Urbana, Illinois



August, 1944



Publications in the Bulletin series report the results of investigations made
or sponsored by the Experiment Station



IMPROVING BLUEGRASS PASTURES

By W. B. NEVENS, Chief in Dairy Cattle Feeding

KENTUCKY BLUEGRASS has long been one of the most
commonly used pasture grasses on Illinois dairy farms. There
are three reasons for the popularity of this grass: (1) it
makes a permanent pasture that requires little reseeding or other
attention; (2) it survives despite close grazing and adverse weather;
(3) the firm sod resists tramping and erosion.

There are definite limitations, however, to bluegrass pastures:

(1) the dry-matter yield and protein content, which are usually high
during May and the first part of June, fall off during midsummer;

(2) the dry-matter yield is also seriously reduced whenever rainfall is
light; (3) the total yearly yields of dry matter and of protein are low.

To find out whether the yield and feeding value of bluegrass
pastures might not be improved by good management, the Illinois
Station conducted a series of experiments from 1909 thru 191.3.
Popular discussions of the investigation were published many years ago 1
but the technical features which answer many questions being asked
today about pasture management were not reported. In view of the
greatly increased interest in pasture improvement in recent years, it
now seems desirable to publish a synopsis of this study.

Three Management Practices Tested

A small tract on the University dairy farm was divided into seven
experimental plots (Fig. 1). The land was level and well drained, had
been in pasture for nine years, and was well sodded with Kentucky
bluegrass.

Each plot was 4 rods long (north and south) and 1 rod wide, or
%o of an acre in area. Woven-wire fencing surrounded the plots and
kept livestock out of the enclosure. )

Harvesting, disking, and manuring. A different management
practice was tried out on each plot in respect to harvesting, disking,
and manuring (Table 1). Each practice and combination of practices

*W. J. FRASER, "Ever-Failing or Never-Failing Pasture," Hoard's Dairyman
67, page 869, 1924. See also book by same author: "Dairy Farming," John Wiley
and Sons, 1930.

215



216 BULLETIN No. 504 [August,

TABLE 1. TREATMENT AND FREQUENCY OF HARVEST AND TOTAL FORAGE
YIELDS OF SEVEN BLUEGRASS PLOTS, 1909-1913



Pounds of green matter per acre


Plot


Treatment


Frequency of
harvest


1909


1910


1911


1912


1913


Total
for five
seasons


1
2

3

4






4
6

5
5


968

232

613
678


3

4

4
5


660
624

680
246


3
3

4

4


182
417

121
249


2 408
2 618

2 584

2 578


1 141

1 248

1 268
1 239


15 359
18 139

18 266
18 990




Once every 2 weeks

Once a week
Once every 2 weeks


Double-disked once in
spring
Double-disked once in
soring. ..



5 Double-disked once in

spring, manured.... Once a week 11 596 13 004 13 863 6 337 4 974 49 774

6 Double-disked once in

spring, manured Once every 2 weeks 12 548 13 910 12 638 5 259 3 760 48 115

7 None Twice a year 6024 6792 5919 2970 2792 24497



was then evaluated according to the effect it had on the yield and
protein content.

Method of harvesting. On each harvest date the entire area of
each plot was harvested with a hand-operated lawn mower equipped
with a grass catcher. The mower was always set to cut the grass at the
same height, and the mowing was done in the afternoon after moisture
from dew or rain had evaporated. The clippings were collected in metal
cans with tight covers.

Method of sampling. Two or three pounds of the forage from
each plot was air-dried in wire-mesh trays with the help of an electric
fan. The trays were 3 feet square and 6 inches deep and lined with thin
muslin. The air-dried samples were then finely ground and analyzed
for moisture, nitrogen, ether extract, and ash.

All in all, more than 400 samples of bluegrass were analyzed and
more than 2,000 chemical determinations made. 1

Frequent Harvesting Reduced Yield

The effect of the frequency of harvest was studied by mowing three
plots (Nos. 1, 3, and 5) weekly and three comparable plots (Nos. 2, 4,
and 6) biweekly from about May 1 to October 1 (except in 1911 when
the harvests were continued thru October).

J Tables showing the detailed chemical analyses covering this investigation,
together with full description of the plan of the experiment, are contained in a
typewritten volume deposited in the Agricultural Library of the University of
Illinois.



1944] IMPROVING BLUEGRASS PASTURES 217

Yearly yield of dry matter. In 10 of the 12 comparisons (Table
2), the plot mowed weekly yielded less forage than the comparable
plot mowed biweekly. An exception to the rule occurred between the
manured plots (5 and 6) in 1911, and again in 1912. The total differ-
ence in yield between the manured plots, however, was less than the
total difference in yield between the disked plots or between the un-
treated plots.

Plot 7, which like Plots 1 and 2 received no treatment, was har-
vested only twice yearly in mid- June and in mid-September. Its yield,



TABLE 2. DRY-MATTER YIELDS OF BLUEGRASS HARVESTED WEEKLY AND
BIWEEKLY, 1910-1913



Pounds of dry matter per acre


Plot Treatment


Frequency of
harvest 1910


1911


1912


1913


Total
for four
seasons


1

2

3
4

5
6




Weekly


1


135
464
329

440
534
94

660
955
295


920
1 071
151

1 168
1 230
62

3 184
3 137

-47


754
818
64

826
829
3

1 764
1 483
-281


387
449
62

411
431
20

1 033
1 099
66


3
3

3
4

9
9


196
802
606

845
024
179

641
674
33


None




1


Difference in favor of biweekly harvest
Disked .... Wppklv


. 1


Disked




. . . . 1


Difference in favor of biweekly harvest
Disked and manured Weekly


. . 3


Disked and manured Biweekly
Difference in favor of biweekly harvest


3



on a green-matter basis (Table 1), was larger than the yield of the
comparable plots (1 and 2), which were harvested at weekly and bi-
weekly intervals respectively. It also supplied more total forage than the
disked plots (3 and 4), which were mowed weekly and biweekly.

Frequent harvesting almost invariably reduced the yearly yield of
dry matter.

Percent of protein in dry matter. Forage harvested weekly was
higher in protein than forage harvested biweekly (Table 3). This was
probably because of the natural tendency of new grass to have a greater
protein content than old grass.

Yearly yield of protein. Altho weekly mowing increased the per-
cent of protein in the dry matter, it reduced the yield of dry matter so
much that there was little difference between the total protein yield
of a plot mowed weekly and a comparable plot mowed biweekly. In 12
comparisons (Table 4) the plot mowed weekly yielded more protein
6 times and the plot mowed biweekly, 6 times.



218 BULLETIN No. 504 [August,

TABLE 3. PROTEIN CONTENT OF BLUEGRASS HARVESTED
WEEKLY AND BIWEEKLY



Percent of protein in dry matter


Plot Treatment


Frequency of
harvest 1910


1911


1912


1913


Average
for four
seasons


1
2

3
4

5
6


None


, . . Weekly


17


.2
.7
.5

,0
,2
,8

,4
.1
.3


22
20
1

23
21.
1

25
22
3.


,6
,7
,9

6
7
,9

,9
.6

,3


17
15

1

17
16
1

20
17

2


,5
.9
,6

,3


,3

,4
.8
,6


16

15

16
16.

20
20


,5

,9
,6

,5
,3
,2

,1

,4
,3


18.7
17.6
1.1

19.4

17.9
1.5

22.6
20.6
2.0






16


Difference in favor of we
Disked ,






. . Weekly


18


Disked


. . Biweekly


16


Difference in favor of we




1


. . Weekly . . .


. . . . 21


Disked and manured
Difference in favor of we


. . Biweekly
ekly harvest


20
1







TABLE 4. PROTEIN YIELDS OF BLUEGRASS HARVESTED
WEEKLY AND BIWEEKLY

Pounds of protein per acre

Plot Treatment Frequency of harvest Total

1910 1911 1912 1913 for four
seasons



1


None Weekly


196


207


132


64


599


2


None Biweekly


244


222


130


71


667




Difference in favor of weekly harvest


-48


-15


2


-7


-68


3


Disked Weekly


259


276


143


68


746


4


Disked Biweekly


249


267


132


70


718




Difference in favor of weekly harvest


10


9


11


-2


28


5


Disked and manured Weekly


. 783


823


359


208


2 173


6


Disked and manured Biweekly


795


708


264


225


1 992




Difference in favor of weekly harvest


-12


115


95


-17


181



The yearly yield of protein averaged a little higher for plots mowed
weekly than for the plots mowed biweekly. This advantage of weekly
mowing was so slight, however, that it was more than offset, for prac-
tical purposes, by the reduction it caused in yield. Hence in considering
the seasonal yields of both forage and protein it appears that constant
close grazing of bluegrass pastures should be avoided. 1

Disking Increased Yield

As soon as the ground was sufficiently dry each spring, two other-
wise untreated plots (Nos. 3 and 4) were thoroly disked lengthwise
and crosswise as many times as possible without turning the sod

'See Bui. 505 of this Station for reports of experiments in which blue-
grass pastures were used as part of a rotational grazing system.



1944] IMPROVING BLUEGRASS PASTURES 219

TABLE 5. DRY-MATTER YIELDS OF DISKED AND UNDISKED BLUEGRASS

Pounds of dry matter per acre



Plot Treatment Frequency of harvest Total

1910 1911 1912 1913 for four
seasons

1 None.. .. Weekly.. 1 135 920 754 387 3 196

3 Disked Weekly 1440 1168 826 411 3845

Difference in favor of disking 305 248 72 24 649

2 None.. . Biweekly -1464 1071 818 449 3802

4 Disked Biweekly 1534 1230 829 431 4024

Difference in favor of disking 70 159 11 -18 222



upside down. They were then rolled with a smooth iron roller 3 feet
in diameter.

Yearly yield of dry matter. Disking increased the yield of dry
matter markedly. The disked plot yielded more forage than the com-
parable undisked plot in 7 of the 8 comparisons (Table 5).

Percent of protein in dry matter. Disking increased slightly the
percent of protein in the dry matter. In the 8 comparisons (Table 6),
the disked bluegrass had a higher percentage of protein 5 times; the
comparable undisked, 2 times ; and once there was no difference.

TABLE 6. PROTEIN CONTENT OF DISKED AND UNDISKED BLUEGRASS



Percent of protein in dry matter


Plot


Treatment


Frequency of
harvest


1910


1911


1912


1913


Average
for four
seasons


1
3

2
4






17


,23
97

.74

.68
24

.44


22
23.
1

20
21


.55
59
.04

,72
66
,94


17
17

15
15


.49
.30
.19

.89
.98
.09


16
16


15
16


49
49

,92
33
41


18.74
19.38
.64

17.56
17.85
.29


Disked


Weekly


. 17


Difference in favor

None
Disked
Difference in favor






. . Biweekly
. . Biweekly


16
. 16







Yearly yield of protein. Disked bluegrass averaged a little more
total protein than undisked. In 3 of the 8 comparisons (Table 7) the
disked grass yielded 20 to 33 percent more protein than the undisked.
Disking, however, caused only a small increase 4 times and a slight
decrease once.

While no determinations of the causes of the increase in yield
brought about by disking were made, it was assumed that disking
destroyed some of the weeds (mostly dandelions) and thus permitted
a denser stand of bluegrass.



220 BULLETIN No. 504 [August,

TABLE 7. PROTEIN YIELDS OF DISKED AND UNDISKED BLUEGRASS

Pounds of protein per acre



Plot Treatment Frequency of harvest Total

1910 1911 1912 1913 for four
seasons



1




196


207


132


64


599


1


Disked Weekly


259


276


143


68


746






63


69


11


4


147


7




244


222


130


71


667


4




249


267


132


70


718






5


45


2


1


Si

















Manuring Increased Both Yield and Protein

Barnyard manure was applied to Plots 5 and 6 at the rate of 23 tons
an acre early in the spring of 1908, 1909, and 1910. 1

Yield of dry matter. Manure always increased the yield of dry
matter. In 7 of the 8 comparisons (Table 8) the manured plot yielded
more than twice as much forage as the comparable unmanured plot.

TABLE 8.- DRY-MATTER YIELDS OF MANURED AND UNMANURED BLUEGRASS



Pounds of dry matter per acre


Plot


Treatment


Frequency of
harvest 1910


1911


1912


1913


Total
for four
seasons


3
5

4
6


Disked.






1


440
660
220

534
955
421


1
3
2

1
3
1


168
184
016

230
137
907


826
1 764
938

829
1 483
654


411
1 033
622

431
1 099
668


3
9
5

4
9
5


845
641
796

024
674
650


Disked,


manured. .


Weekly


3


Difference in favor of i

Disked
Disked, manured
Difference in favor of i




2


.... Biweekly
. . . . Biweekly
nanuring


1
3
. . 2







The yield of the plots which were not manured declined from year
to year (see Plots 1 and 2 in Table 2 and Plots 3 and 4 above). This
progressive decline occurred largely because the soil fertility which was
removed with the harvested forage was not restored, altho low rainfall
was also a factor in 1912 and 1913.

Percent of protein in dry matter. Manured grass was always
richer in protein than comparable unmanured grass. In the 8 compari-
sons (Table 9) the protein content of the manured grass ranged from

J A notation was made in the records that manure was also applied in 1911
at the rate of 20 tons an acre, but no recorded weights of manure for that year
were found.



1944] IMPROVING BLUEGRASS PASTURES 221

TABLE 9. PROTEIN CONTENT OF MANURED AND UNMANURED BLUEGRASS



Percent of protein in dry matter


Plot


Treatment


Frequency of
harvest


1910


1911


1912


1913


Average
for four
seasons


3

5

4
6


Disked


Weekly


17
. 21
3

16
. 20.

3.


.97
40
43

24

id

86


23
25

2,

21.

22,


.59
86

27

66
56
90


17
20
3

15

17
1


.30
.38
.08

.98
.83
.85


16
20

3.

16
20

3.


49
10
61

33
43
10


19.38
22.55
3.17

17.85
20.59
2.74


Disked, manured
Difference in favor oi

Disked


. . Weekly
manuring




Disked, manured. . . ,
Difference in favor oi


. . Biweekly





one-twentieth to one-fifth higher than the protein content of the
unmanured grass.

Yearly yield of protein. Altogether the manured plots yielded two
to three times as much protein each year as the unmanured (Table 10).
This was due both to the increase in the yield of dry matter and to
the rise in the percentage of protein.

TABLE 10. PROTEIN YIELDS OF MANURED AND UNMANURED BLUEGRASS

Pounds of protein per acre



Plot Treatment Frequency of harvest Total

1910 1911 1912 1913 for four
seasons

3 Disked Weekly 259 276 143 68 746

5 Disked, manured Weekly 783 823 359 208 2 173

Difference in favor of manuring 524 547 216 140 1 427

4 Disked Biweekly... . 249 267 132 70 718

6 Disked, manured Biweekly 795 708 264 225 1 992

Difference in favor of manuring 546 441 132 155 1 274



Bluegrass Thrived With Heavy Rainfall

Rainfall varied a great deal from season to season (Table 11), and
yields varied accordingly (Tables 1, 2, 5, and 8). Rainfall was above
normal in May, June, and July of 1909 and below normal the same
three months of 1911.

Yields of dry matter and the protein content were always higher
when rainfall was heavy. In 1913, when rainfall was extremely low
from May thru September, the yields fell to one-half to two-thirds the
amounts harvested the preceding year.

Manure beneficial in all seasons. The difference between the
protein contents of manured and unmanured bluegrass stayed about
the same regardless of weather conditions and the development of the



222



BULLETIN No. 504



[August,



TABLE 11. RAINFALL AT URBANA DURING PASTURE SEASONS, 1909-1913*

(Inches)



Year


May


June


July


August


Septem-
ber


October


Total
for six
months


1909


. 5


58
35
44
16
56
97


3.75
2.99
.80
1.89
1.67
3.50


7
2

3
1,
3


.57
.76
.62
.68
.52
00


2
2
3
2
1
3


.37
.62
.35
.06
.44
.65


2.
4,

8,
1,
2,
3.


36
.14
90
76
50
35


2.25
1.34
3.10
2.95
4.03
2.67


23.88
19.20
19.21
16.50
11.72
20.13


1910


. 5


1911


. 2.


1912


. 4


1913




Fifteen-year average, 1906-1930


. 3.



Data are from Illinois Cooperative Weather Bureau.



grass (Fig. 2). Altho dry weather lowered the dry-matter and protein
yields of all plots, the manured grass continued to yield more dry
matter and protein than the unmanured (Fig. 3).



30





30
20
10

o

30

20
10


30

20

10





MAY JUNE JULY AUG. SEPT. OCT.

10 20 30 10 20 30 10 20 30 10 20 30, 10 20 30 10 20




1910



1912




PLOT 3 -CONTROL
PLOT 5 -MANURED



10 20 30 10 20 30 10 20 30 10 20 30 10 20 30 10 20
MAY JUNE JULY AUG. SEPT. OCT



Fig. 2. Protein content of fertilized and unfertilized bluegrass. Manured
grass was consistently higher in protein than unmanured grass during all
four seasons. Altho the heavy rains during the latter part of August, 1911,
and thru September caused considerable increase in protein content, the
difference between fertilized and unfertilized grass remained about the same.
(The rainfall from May thru September was 17.86 inches in 1910, 16.11 inches
in 1911, 13.55 inches in 1912, and 7.69 inches in 1913.)



1944]



IMPROVING BLUEGRASS PASTURES



223




MJJASO MJJASO MJJASO MJJAO
1910 1911 1912 1913
PLOT 3 - NOT MANURED



MJJASO MJJASO MJJASO MJJAO

1910 1911 1912 1913

PLOT 5 - MANURED



Fig. 3. Yields of dry matter and protein from fertilized and unfertilized
bluegrass plots. The application of barnyard manure had a profound effect
on the yields of both dry matter and protein. Grass that was fertilized with
barnyard manure had twice as high a dry-matter yield and almost three
times as high a protein yield as unfertilized grass.

Reliability of Results

Bluegrass did well under some experimental management practices
and poorly under others. To determine whether the different results
were caused solely by the three management practices and not partly by
chance, all data were analyzed by Student's method 1 (Table 12).

In four instances the odds that the result was caused by factors
other than chance were so large that there was no doubt at all that the
result was due to the management practice: (1) the effect of fre-
quent harvest on protein content; (2) the effect of manure on yield
of dry matter; (3) the effect of manure on protein content; and
(4) the effect of manure on yield of protein.

The odds of 58:1 for the effect of disking on dry-matter yield were
also large enough to indicate that this practice was the cause of the

STUDENT. The probable error of a mean. Biometrika 6, Part 1, page 19. 1908.



224 BULLETIN No. 504

increases obtained. The odds of 12:1 for the effect of frequency of
harvest on dry-matter yield and the odds of 15:1 for the effect of disk-
ing on protein content were smaller than desirable but still fairly
dependable.

TABLE 12. RELIABILITY OF BLUEGRASS TRIALS



Table


Effect of


Number
of com-
parisons


Mean value
of
differences


Oddsl:


2




12


68.17


12


4




12


1.39


3 333


5




12


11 75


5


6




8


108 90


58


7




.... 8


.32


15


8




8


24.75


4


9




8


1 431


1 508


10




8


2.76


10 000


11




.... 8


337 . 60


1 136













"Student's odds that the differences were caused by factors other than chance.

The odds for the effect of frequent harvesting and of disking on
yields of protein were, respectively, only 5:1 and 4:1. The results in
these two instances, therefore, cannot be considered proof that these
two practices are of any benefit. In fact, under ordinary farm condi-
tions neither could be expected to increase the yields of protein in
bluegrass pastures.

Summary and Conclusions

Frequent harvesting reduces bluegrass yield. Bluegrass har-
vested weekly had a slightly higher percent of protein than blue-
grass harvested biweekly. Weekly harvesting, however, reduced slightly
the yearly yield of dry matter but had no significant effect on the total
amount of protein.

Disked bluegrass supplies more forage than undisked. Double-
disking once in the spring increased the yearly yield of dry matter to
a considerable extent. The percentage of protein was increased only
a small extent, while the total amount of protein was not significantly
changed.

Manuring increases markedly both the yield and the protein
content of bluegrass. The application of barnyard manure more than
doubled the yearly yield of dry matter, increased the percent of protein
in the dry matter by one-sixth, and nearly trebled the total amount of
protein.

Yields declined when grass was harvested over a period of years
without fertility being returned to the soil.

80508-44 28108





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Online LibraryW. B. (William Barbour) NevensImproving bluegrass pastures : review of an early experiment on the effects of frequency of harvest, disking, application of barnyard manure on yields and protein content → online text (page 1 of 1)