| Abstrakt: |
A three-year study was made of the effects of autumn-, winter- and spring-grazing, and of the level of nitrogen applied in single and split spring dressings, on seed crops of S.37 cocks- foot and S.215 meadow fescue, both leafy hay strains. 1. In cocksfoot, grazing between October and April stimulated the production of fertile tillers but reduced weight of seed per tiller. Net yield was reduced by April or May grazing, but not by winter grazing. As the crop aged, the extra tillers induced by grazing between October and April served to maintain seed yield at a higher level than that of the control. 2. All cocksfoot plots responded to a spring dressing of 3 cwt. Nitro-chalk per acre. Ungrazed plots and plots grazed before April responded to 6 cwt. 3. In meadow fescue, grazing did not stimulate tillering to the same extent, but had little effect on weight of seed per tiller. This grass also tolerated grazing later in spring than did cocksfoot. The aggregate seed yield over the three years was enhanced by grazing between October and April. 4. Meadow fescue responded to a spring dressing of 2 cwt. Nitro-chalk per acre, but not to heavier dressings. 5. Yield fell more sharply in cocksfoot than in meadow fescue in the second and third years, even where spring dressings of nitrogen were applied. 6. No significant difference was recorded, in the seed yield of either strain, between a single dressing of nitrogen in March and a similar quantity divided between March and May dressings. [ABSTRACT FROM AUTHOR] |
