NITROGENOUS FERTILIZATION OF ITALIAN RYEGRASS IN SPRING

A series of experiments in eastern Scotland, carried out over a 7–year period, on the application of N fertilizers to Italian ryegrass for producing early spring grass, indicated that maximum yields are likely to be produced if the fertilizer is applied not later than the middle of March in most seasons. Only rarely did application in February result in a loss of N and in reduced herbage yields. Italian ryegrass appears to be able to make some growth at temperatures below 40†F. Increasing the rate of N application resulted in increased DM yield, the response averaging 9–4 lb DM per lb N. Herbage N concentration was increased by the additional N fertilizer. Nitro–chalk and ammonium sulphate were equally effective in producing early grass, irrespective of application date.