Effect of phosphorus and sulphur on growth and yield of soybean (Glycine max L.).

A field experiment was conducted at Sher-e-Bangla Agricultural University Farm, Dhaka, Bangladesh from December 2008 to April 2009 to evaluate the effect of P (viz. 0, 15, 30, 50 kg P2O5 ha-1) and S (viz. 0, 10, 20, 40 kg S ha-1) and their interaction on the growth and yield of soybean (Glycine max L.). Individual application of different levels of phosphorus and sulphur showed significant effect on yield and yield attri­butes studied. Among them, plant height, number of primary branch plant-1, number of leaves plant-1, stover yield increased significantly up to 50 kg P ha-1. On the other hand, numbers of pods plant-1, number of seeds plant-1, thousand seed weight, grain yield, biological yield increased significantly up to 30 kg P ha-1. However, in case of S, the positve response was observed only upto 20 kg S ha-1. The combined applica­tion of phosphorus @ 30 kg P ha-1 and sulphur @ 20 kg S ha-1 gave rise to the highest number of pods plant-1 (30.07), number of seeds plant-1 (84.94), thousand seed weight ( 94.61 g), and in turn produced highest grain yield (2.29 t ha-1). Thus, the combined application of 30 kg Phosphorus ha-1 and 20 kg Sulphur ha-1 may be considered to be optimum for getting higher yield of soybean.