ALBERT

Description: SUMMARY1. The importance of uniform production of herbage for crop-drying is emphasized.2. A replicated experiment is described which compared four crops, two annuals and two leys under four manurial treatments which included a control and three applications of fertilizer (3½ cwt. ‘nitrochalk’) distributed during the season in three ways.3. Vetches yielded 2500–3000 lb. dry matter per acre of 28–30% crude-protein content in two cuts.Barley yielded 2500–3000 lb. dry matter per acre of 18–21% crude protein in five to six cuts.Leys yielded 4000–5000 lb. dry matter per acre of 15–18% crude protein in four cuts in their first year, and 5000–6000 lb. dry matter per acre of 15–18% crude protein in five cuts in their second year.

Description: 1. An experiment was carried out from 3 May to 10 October 1949 to compare close-folding with rotational grazing of dairy cows. With close-folding the cows were moved daily to an area of fresh pasture which was calculated to supply the day's feed requirements; the rate of stocking ranged from 50 to 80 cows per acre. With rotational grazing the cows were stocked on pasture at the rate of 6–8 cows per acre and moved from one pasture to another at intervals of 5–14 days. Two uniform groups of Ayrshire cows were used, and each group spent a period on each system of grazing. Two pastures, a ryegrass-dominant old pasture and a cocksfoot-dominant ley, were used, and as far as possible the pasture grazed by both groups of cows was similar. Nitrogenous top dressings up to 104 Ib. nitrogen per acre in the season were applied uniformly to both the close-folding and rotational areas. No supplementary feeding was given to the cows.2. The best methods of close-folding practised gave 215 and 201 cow-days of grazing per acre with 550 gal. milk per acre from the cocksfoot ley and 582 gal. from the permanent pasture. Rotational grazing on the same two pastures gave 181 and 138 cow-days and 450 and 351 gal. milk per acre respectively.

Description: 1. Two experiments are described in which nine manurial treatments were applied ranging from no application to an application of 312 lb. N, 135 lb. P2O5 and 168 lb. K2O per acre in one season. Some treatments included one or more massive dressings of nitrogen (104 lb./acre), while others received several light dressings spread over the season. The applications were made at differing periods of the season. In one experiment (Series 3) the treatments were applied to a 1-year Italian ryegrass ley, in the other (Series 4) to an established ryegrass pasture.

Description: 1. The experiment previously described (series 4, Holmes, 1949) on the effect of massive applications of nitrogenous fertilizers on the productivity of a ryegrass dominant pasture was continued for 3 years (1946, 1947, 1948). The manurial treatments ranged from none to the application of 312 lb. nitrogen per acre and this was applied with and without 135 lb. P2O5 and 168 lb. K2O per acre. Farmyard manure was applied to one block in 1948.2. With the heaviest nitrogen treatment plus phosphate and potash the average yield for 3 years was 8000 lb. dry matter and 1640 lb. crude protein (similar to the yield in 1946) compared with a control yield of 4720 lb. dry matter and 590 lb. crude protein. The yields declined from year to year when phosphate and potash were not applied, the decline being greatest with the heaviest application of nitrogen.3. The seasonal distribution of the yield of herbage was very considerably modified by the time when fertilizers were applied.4. The botanical composition of the swards was related to the yield, 70% of the grasses in the highest yielding sward being perennial ryegrass and cocksfoot while the lowest yielding sward contained only 35% of these grasses.5. The manurial treatments had no effect on the pH, loss on ignition or the content of readily soluble P2O5 in the soil, but in the first year there was some evidence of a general reduction of readily soluble K2O to a low level.

Description: 1. In continuation of experiments made in 1949 (Holmes et al. 1950) an experiment was carried out from 7 May until 23 September 1950, to compare close-folding and rotational grazing of cows on pastures which were liberally treated with nitrogenous fertilizer. With close-folding the cows were moved daily to an area of fresh pasture calculated to supply the day's feed requirements; the rate of stocking for the day ranged from thirty to sixty-five cows per acre. With rotational grazing the cows were stocked on pasture at the rate of seven to eight cows per acre and moved from one pasture to the other at intervals of 3–4 days. Two uniform groups of six Ayrshire cows were used in a double reversal layout with four periods each of 5 weeks. The same pastures as in 1949—a permanent pasture and a cocksfoot ley—suitably divided by electric fences were used. No supplementary feeding was given.2. The average yield per acre from close-folding was 241 cow-days, 732 gal. of milk and 320 lb. live-weight gain—equivalent to 632 lb. digestible crude protein and 4316 lb. starch equivalent. Rotational grazing on similar adjoining paddocks gave 181 cow-days, 557 gal. of milk and 285 lb. liveweight gain per acre, equivalent to 486 lb. digestible crude protein and 3371 lb. starch equivalent.3. The average daily milk yield per cow was 29·5 lb. for one group and 30·2 lb. for the other. For close-folding it was 29·6 lb. and for rotational grazing it was 30·1 lb., none of the differences being significant. Nor were any differences in the average live weight of the groups or in their live-weight gains significant.4. The increased production per acre from closefolding compared with rotational grazing—amounting to 20–40%—could be related to the increased efficiency with which the available pasture was consumed.5. Close-folding had no harmful effect on the pastures. Although the season was exceptionally wet, poaching occurred only in the gates and alleyways. 6. The frequent applications of nitrogenous fertilizer throughout the season maintained regular production of good herbage. In June and July, however, despite the fertilizer applied, the crudeprotein content dropped on some paddocks to 13% of the dry matter, a figure barely sufficient to maintain high milk yields.7. Comparison of the production per acre in 1950 with that in 1949 where close-folding was used, showed an increase of 34% in starch equivalent utilized on the permanent pasture. For each extra cwt. ‘Nitro-Chalk’ applied in 1950 over that in 1949, 190 lb. starch equivalent were produced. On the cocksfoot the response to additional nitrogen was reduced because of potash deficiency induced by cropping for grass-drying in 1948.8. The factors affecting the increased production from close-folding and the fertilizer requirements of pasture are discussed.

Description: 1. A small-scale plot experiment which had been carried out from 1947 to 1949 (Holmes, 1951) to study the effect of massive dressings of nitrogen, with and without phosphate and potash, on the yield of a ryegrass dominant sward was continued in 1950–2. A 4 × 4 Graeco-Latin square was used.The nitrogen treatments applied each year were:(1) no nitrogenous fertilizer, (2) 260 lb., (3) 520 lb. and (4) 416 lb. (312 lb. in 1951) nitrogen per acre per annum applied in four or five equal dressings, one for each cut. Treatments 1, 2 and 3 were cut each time they reached the long leafy stage (8–11 in. in height), treatment 4 was cut when 13–16 in. in height.The mineral treatments were (A) no mineral fertilizer, (B) 336–538 lb. K2O per acre per annum depending on nitrogen treatment, (C) 120–180 lb. P2O5 per acre per annum, (D) treatments B and C combined. Mineral applications were applied in four or five dressings each year, one for each cut.2. Applications of phosphate did not affect the yield or protein content of the herbage, but yields were severely restricted in the absence of potash. Where potash was applied the yields under each nitrogen treatment were maintained or increased over the 6-year period. Average yields of dry matter for the 6-year period when potash was present were 4760, 8050, 9620 and 9320 lb. per acre per annum for treatments 1, 2, 3 and 4. Without potash the corresponding average yields were 3980, 5610, 5190 and 5100 lb. Average crude protein yields with potash were 710, 1410, 1990 and 1640 lb. per acre per annum and without potash 550, 1090, 1190 and 1020 lb.3. The presence of potash resulted in earlier growth in each season through the maintenance of the earlier vigorous grasses in the sward. Although the growth curve was variable with treatment 1, treatments 2, 3 and 4 gave nearly uniform distribution of herbage production over the season.4. The weighted mean contents of crude protein for each year ranged from 13·9% for treatment 1 to 20·6% for treatment 3 when potash was given and from 12·9% for treatment 1 to 23·6% for treatment 3 when potash was absent. There was a gradual increase in protein content at the later cuts in each season, but the range was less where nitrogen was applied.5. The efficiency of utilization of fertilizer nitrogen was calculated. When the yield was compared with that of a no-clover sward the average response was 15·6, 10·8 and 11·8 lb. dry matter per lb. of nitrogen applied for treatments 2, 3 and 4 respectively. In terms of crude protein the percentage recovery was 53, 44 and 42 respectively. When the yields were compared with those of the clovery swards the nitrogen recovery figures were reduced by about one-third.6. The botanical composition of the plots was determined by the nitrogen and potash treatments. Where both were adequate a vigorous sward of ryegrass and timothy was maintained. Where nitrogen was absent but potash present a clovery sward developed. In the absence of potash with or without nitrogen the better grasses declined and were replaced by poor grasses.7. Provided potash was applied there were no marked changes in the soil analysis.8. The results are discussed with particular reference to the maintenance of high grass yields and the relative roles of clover and fertilizer nitrogen.

Description: 1. An experiment is described which lasted for 5 years and in which a comparison was made of twelve grasses or grass mixtures under different fertilizer nitrogen treatments and also when grown with clover. The herbage was cut 4–6 times in each season. Adequate amounts of mineral fertilizers (280–340 lb. K2O and about 100 lb. P2O5 per acre per annum), and the following nitrogen treatments were applied: (1) no nitrogen, no clover, (2) grass sown with clover, (3) 140–208 lb. nitrogen per acre per annum in four to six equal dressings, (4) 350–416 lb. nitrogen per acre per annum in five and six equal dressings.In 1951, 1952 and 1953 the clover dominant swards (treatment 2) were split between the following treatments; (X) as (3) above, (Y) 35 lb. nitrogen per acre in spring and again in late summer, (Z) no nitrogen as (2) above.2. The average yields for the 4 years were 2180, 5940 and 8300 lb. dry matter per acre, and 290, 850 and 1460 lb. crude protein per acre for treatments 1, 3 and 4. With treatment 2 the average yields were 2830 lb. dry matter and 400 lb. crude protein in 1949 and 4270 lb. dry matter and 820 lb. crude protein in 1950. An approximate average yield for the 4 years from treatment 2 was 4630 lb. dry matter and 860 lb. crude protein. In 1951–3 average yields for treatments 2X, 2Y and 2Z were, 7240, 6340 and 5750 lb. dry matter and 1240, 1180 and 1100 lb. crude protein per acre.3. There were considerable differences between grasses in nitrogen response and compatibility with clover. The highest yields with fertilizer nitrogen were given by cocksfoot strains, but, in the presence of clover, ryegrass and timothy strains gave the highest yields. There were also differences between strains within each species.4. Mean crude protein contents were, for treatments 1, 3 and 4, 13·3, 14·3 and 17·6%, and for treatments 2X, 2Y and 2Z in 1951–3, 17·2, 18·6 and 19·1%. Differences between species were significant in only a few instances.5. The distribution of yield over the season was most regular with treatment 4. Cocksfoot species gave the least variable yields from cut to cut, while those from timothy and ryegrass swards were the most variable.6. Treatments 3 and 4 maintained a high proportion of sown grasses in the swards. In treatment 2 the clover percentage rose to a high level by 1950. A high percentage was maintained under treatment 2Z in 1951–3. Treatment 2Y depressed the clover content in some grasses, and treatment 2X further depressed it in those grasses. A fairly high clover content was maintained, however, even with treatment 2X with some timothy strains and meadow fescue.7. The mineral fertilizers applied maintained the soil analysis at a satisfactory level.8. The results are discussed with special reference to the relative merits of fertilizer nitrogen and clover nitrogen and to the differences between species and strains.

Description: 1. Experiments were carried out in 1956 and 1957 in which milking cows were grazed at the same stocking rate, either on strip grazing or on free grazing. The cows followed balanced Latin Square designs.2. The pastures were liberally fertilized, either with NPK fertilizer (202 lb. N, 202 lb. P2O5, 252 lb. K2O per acre in 1956 and 80% of these quantities in 1957), or with PK fertilizers (269 lb. P2O5 and 269 lb. K2O in 1956 and 80% of these quantities in 1957), and a subsidiary comparison of the effect of nitrogenous fertilizers was made in 1956.3. At the end of the main experiment in 1956 a study of the effect of straw offered to the grazing cows was made. No supplement other than straw was offered.4. The results in both years showed no difference in milk yield per cow due to treatments, nor in 1956 was milk yield or milk composition affected by grazing treatment, fertilizer treatment or the provision of straw.5. In both years the live-weight gain per cow was less with free grazing. In 1956 the provision of straw increased the rate of live-weight gain. It is suggested that these differences are mainly due to gut fill.

Description: 1. An experiment with dairy cows is described in which the production per animal and per acre obtained in three methods of grazing management were compared during 2 years.(A) An intensive method. Strip-grazing daily on heavily fertilized grass sward.(B) A modified intensive method. Continuous, free-range grazing on a heavily fertilized grass sward.(C) An extensive method. Continuous, free-range grazing on a grass and clover sward receiving a basic application of phosphate and potash only.The intensively fertilized swards received a total of 212 lb. fertilizer nitrogen per acre, together with adequate amounts of phosphate and potash throughout the grazing season. No supplementary foods of concentrate type were fed to the cows during the experiment.2. For the comparison of production per animal 3 × 3 Latin-square experimental design, with twelve Ayrshire cows and periods of 3 weeks' duration, was used. Two separate trials were conducted during the grazing season of 1955 and a third trial during 1956.3. The different methods of grazing management and intensive use of fertilizer had little influence on the milk yield and butterfat percentage of the milk of the cows.

Description: 1. A small-scale plot experiment which had been conducted from 1947 to 1952 to study the effect of massive dressings of fertilizer nitrogen, with and without phosphate and potash, on the yield and quality of a rye-grass dominant sward was continued from 1953 to 1958 with two changes in the mineral treatments in 1953. A 4 × 4 Graeco-Latin square was used.The nitrogen treatments applied each year were: (1) no nitrogenous fertilizer, (2) 260 lb. nitrogen, (3) 520 lb. nitrogen and (4) 416 lb. nitrogen per acre per year.The mineral treatments were: (A) no mineral fertilizer, (B) 336–504 lb. K2O per acre per year depending on nitrogen treatment, (C) 101–202 lb. K2O and 81–101 lb. P2O5 per acre per year depending on nitrogen treatment, and (D) no mineral fertilizer after 1953, although K2O and P2O5 had been applied during the previous 6-year period.All the fertilizers were applied in four or five equal dressings each year, one for each cut.Treatments 1 and 4 were cut four times and treatments 2 and 3 five times per year.2. Applications of phosphate did not affect the yields of herbage dry matter or crude protein, but yields were severely depressed in the absence of potash. With adequate potash the yields under all nitrogen treatments were maintained for the 6-year period and were at the same level as in the previous 6-year period. The mean yields of dry matter for the 6-year period when potash was applied were 5200, 8420, 10,180 and 9700 lb. per acre per year for treatments, 1, 2, 3 and 4. Without potash the corresponding mean yields were 5460, 6410, 6210 and 6880 lb. Average crude protein yields were 760, 1360, 1940 and 1660 lb. per acre per year with potash and 780, 1100, 1220 and 13201b. without potash.3. The weighted mean contents of crude protein for the 6-year period averaged over all the mineral treatments were 14·4, 16·7, 19·4 and 18·2% for nitrogen treatments 1, 2, 3 and 4. The mean crudeprotein contents of treatments with and without potash were 16·7 and 17·6%, respectively.4. The average response to nitrogen was 15·0, 10·9 and 12·4 lb. dry matter per 1 lb. of nitrogen applied on treatments 2, 3 and 4, respectively, compared with a no-clover sward, and 7·8, 7·3 and 7·9 lb. compared with a grass + clover sward. The recovery of nitrogen in terms of crude protein was 45, 40 and 40% for treatments 2, 3 and 4, respectively, when compared with a no-clover sward.5. The botanical composition of the plots continued to be determined by the nitrogen and potash treatments. On plots receiving ‘Nitro-Chalk’ clover was virtually non-existent, whereas on plots which received potash and no nitrogen, clover was present. With a combination of potash and nitrogen vigorous swards of timothy were found but if only nitrogen and no potash was applied, poorer grasses, such as Festuca rubra, were dominant.6. Soil analyses showed increased pH values and decreased contents of Mg with increasing applications of ‘Nitro-Chalk’. P2O5 values were low except where phosphate was being applied. The most marked change was in the K2O values which varied from 4 units on treatments A and D which received no minerals to 40 units on treatment B which received the heavy dressings of potash.7. Mineral analyses of the herbage for 1953 and 1958 are given. High K contents were found on treatments where potash was applied and this was associated with decreased Mg and Na contents.8. Some details are given of a field-scale trial on the Institute farm where high levels of nitrogen and potash have been applied for 11 and 12 years with successful results.