SUMMARIES OF PAPERS PRESENTED AT A SYMPOSIUM OF THE BRITISH GRASSLAND SOCIETY AND THE FERTILIZER SOCIETY, HELD IN LONDON ON 25 APRIL 1974.

The article presents summaries of research papers presented at a symposium of the British Grassland Society and the Fertilizer Society that was held in London, England on April 25, 1974. The quantity of nitrogen fertilizer necessary to obtain a given yield from grassland depends on the nitrogen contribution from non-fertilizer sources, that is, soil, legume and animal excreta. Although the use of nitrogen fertilizer on grassland has been recognized for a considerable time as an effective means of increasing the output of milk per unit area, relatively low levels are still used on a national basis. The response of grass to nitrogen fertilizer is variable in terms of the yield obtained for a given rate of nitrogen or the yield increment for each unit of nitrogen applied.