Fertiliser requirements of spring oilseed rape

Abstract Because of the increasing importance of oilseed rape in the United Kingdom, 26 field experiments were done on the fertiliser requirements of the spring‐sown crop in the years 1973 to 1975. Seed and oil yield were increased by nitrogen in 23 of the 26 experiments, though oil content was reduced somewhat. On average, the crop required 187 kg/ha of N for optimum yield and there was little difference in yield between seedbed and split N applications. Response to P was small on average, varied between years and was not well correlated with soil analysis; a 2 tonne/ha crop removes about 32 kg/ha P2O5. Mean response to K was very small and a 2 tonne/ha crop removes about 15 kg/ha K2O; spring oilseed rape appears to require no applied K, except perhaps on soils of low K status. The crop did not respond at all to application of S.