Comparison of inorganic fertilizers and cattle sluny for meeting nitrogen needs of maize and potatoes

Application of cattle slurry to maize and potatoes was compared with inorganic N fertilizers in greenhouseand field experiments. Application of equivalent amount of inorganlc N through cattle slurry gave significantly more dry matter yield of maize than ammonium sulphate. The recovery of labelled nitrogen in plants plus soil by the end of the experiment at 40 days was 92% with ammonium sulphate alone and 78% with cattle slurry. During the first 20 days with cattle slurry almost one third of the labelled nitrogen became immobilized in organic matter. In the same period there was mineralization but the overall reaction was net immobilization. In later period there was mineralization which was more than that with ammonium Sulphate. In a field experiment, response to NH₄NO₃ was significant only with 70 kg N ha⁻¹, and was less than cattle slurry (containing 170 kg organic N and 108 kg Inorganic Nha⁻¹). produced a total dry matter yield that was higher, though not significantly so, than ammonium nitrate (70 to 750 kg Nha⁻¹.) Incorporation of wheat straw (5 t ha¹) into slurry did not Influence the yield.