LIBRARY OF THE UNIVERSITY OF ILLINOIS G30.7 no.499-513 cop- 2 A6RICULTURF i 1 e 2u 1 7 n * w "" Libfary Material8 ' The M ""' The person charging this material is responsible for its return to the library from which it was withdrawn i or before the Latest Date stamped below. , n ' " nd Undertinin 9 f b o<8 are reason, for discipli- o B n MT I"*! rMUlt '" di9mi89al from the University. To renew call Telephone Center, 333-8400 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