Critical Plant Sulphur Content and Effect of S Application on Grain and Oil Yield of Rainfed Soybean in Vertic Ustochrepts

Laboratory and field experiments were carried out for two years (1990 & 1991) in Islamnagar 3 and 4 soil series (Vertic Ustochrepts), to evaluate the response of soybean to sulphur and to establish the critical limit of sulphur in soybean plants. In nine field experiments, optimum response to sulphur was recorded at 40 kg S ha⁻¹. Application of S also significantly increased the S up.take, oil content of grain and oil yield. Using data obtained from 30 field experiments over two years, plant critical S limit was 0.34 per cent.