Effect of Phosphorous Application on Yield and its Uptake by Soybean (Glycine max L.) in Different Cropping Systems

Abstract

Background: Soybean-wheat is the most dominant soybean based cropping system and it also fits well in soybean-spring maize and soybean-gobhi sarson cropping systems. Soybean being a highly nutrient-exhaustive crop requires higher amounts of nutrients, particularly phosphorus for its optimum production. Thus, the present investigation was undertaken. Methods: A field experiment was conducted for three years to study the effect of phosphorous application on yield and P uptake by soybean in different cropping systems. There were three cropping systems which were kept in main plots and five P levels viz., 0, 20, 40, 60 and 80 kg P2O5 ha-1 applied to soybean which were kept in the sub plot. Result: Application of 80 kg P2O5 ha-1 resulted in highest mean seed yield of soybean (20.9 q ha-1) but significant response was observed up to 40 kg P2O5 ha-1 (19.8 q ha-1) only. Highest mean seed P uptake of soybean was observed under application of 80 kg P2O5 ha-1. The mean seed yield, stover yield and P uptake of soybean was not affected significantly under different cropping systems. The interaction effects of cropping system and applied P levels were however non-significant. A significant build-up of available P in surface soil over control was observed under 80 kg P2O5 ha-1 level.