ALBERT

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.