Herbage production from organic farms.

摘要

Herbage production was measured on 82 organic fields in the UK, and a method of predicting herbage yield from factors including soil type and depth, number of grass growing days (based on growing season rainfall, altitude and latitude) and N fertilizer rate was tested. Herbage yield could be predicted from site characteristics with reasonable accuracy. Yield varied between years, and was correlated with available soil P. Soil humus increased over time more rapidly in leys than in permanent pastures. White clover [Trifolium repens] averaged 33.4% of the sward in leys and 19.4% in permanent pastures, while in leys herbage yield was correlated with percentage clover, and percentage clover was positively correlated with available soil P and K.