The effects of cattle slurry and inorganic fertiliser nitrogen on the yield and mineral composition of forage maize. results of preliminary experiment

Four rates of cow slurry (0, 35, 70 and 105 t/ha) and inorganic nitrogen (0, 40, 80 and 120 kg/ha) were applied in a factorial arrangement to forage maize plots on a sandy loam soil (Hurst Series). The response of maize DM yield to inorganic N was small above 40 kg N/ha. Slurry alone gave satisfactory yields and up to 70 t/ha improved the response to inorganic N. Slurry at 105 t/ha tended to delay crop maturity and reduced yields when more than 40 kg inorganic N/ha was applied. The percentage N, P and K in the soil before drilling and in the crop at the silage stage were positively related to the amount of slurry applied. Appreciable amounts of P, K and Mg remained in a “plant available” state in the soil after the maize harvest.