Increasing nitrogen use efficiency in upland soils

Abstract

An investigation was carried out at the College of Agriculture, Vellayani, during the year 1980-81 to study the efficacy of the use of some of the commonly available non-edible oilcakes as nitrification inhibitors to increase the nitrogen use efficiency in rainfed upland soils of Kerala. Urea was mixed with neem, mahua, maroti, rubber or karinja cakes at 5:1, 5:2 and 5:3 ratios (urea : oil -cake) to obtain a blend. The mineralisation pattern of those blends were studied along with untreated urea in an incubation study in a typical red loam upland soil kept at 60 per cent field moisture capacity to screen them for nitrification inhibitory properties. Selected blends at the most efficient ratio of mixing were tried in the field at 3 levels of nitrogen supply with cassava as the test crop. The experiment was laid out in randomised block design in factorial structure.