The effects of different levels of nitrogen and sulphur on the yield and composition of tussock grassland

摘要

Abstract Nitrogen and sulphur were applied to undisturbed fescue tussock grassland to determine whether these nutrients interacted in grass production, at what levels of application the interaction occurred, and what changes in the proportions of the species took place. Total herbage yield for the period from March 1959 to March 1960, measured from 4 cuts, was significantly increased to the same extent by an application of either 20 lb or 100 lb sulphur per acre when 400 lb nitrogen per acre was also applied. The total fertiliser was applied in 2 split dressings in January and October. Where both nitrogen and sulphur were applied together, Yorkshire fog showed a superior yield response to that obtained with sweet vernal. Where sulphur was not applied and nitrogen was not limiting, sweet vernal was the superior competitor for the nitrogen and available sulphur. The combined yield of brown-top-danthonia was less than that +of sweet vernal at all cuts except the final one, when this category showed a changed...