A field experiment on soybean was conducted at the regional research farm of the Punjab Agricultural University, Naraingarh (Distt. Fateh Garh Sahib) for three years under irrigated conditions for productivity enhancement through integrated nutrient and other agronomic interventions. There were twelve treatments comprising different levels of N, P, K, FYM and agronomic management practices. The results revealed that soybean significantly responded to the application of N, P, K and FYM. Maximum yield was recorded in the treatment where FYM was applied with NPK and resulted in an increase of 10.8 per cent over NPK alone. Application of additional 30 kg N ha-1 at pre-flowering or at pod initiation did not significantly enhance the yield over the basal dose of NP applied at sowing. Application of 4 tonnes wheat straw mulch + 30 kg N +60 kg P2O5 and 30 kg N + 60 kg P2O5 ha-1 showed similar effect on seed yield of soybean. No statistical difference in soybean yield was observed in the conventional flat and bed sowing treatments. Pre-emergence application of pendimethaline @ 1.5 l ha-1 along with one hand weeding at 40 days after sowing (DAS) and two hand weeding at 20 and 40 DAS were equally effective for weed control and in influencing the soybean yield. The application of N, P, K and FYM, in different treatments, treatment with Bradyrhizobium japonicum and sowing on beds all significantly improved the N, P and K uptake by soybean over control. Application of FYM to soybean resulted in maximum nutrient uptake by soybean. After three years a significant improvement in soil organic carbon, available N, P and K was observed in all treatments over control.
Nutrient Uptake and Removal by Potato Cultivars as Affected by Phosphate Fertilization of Soils with Different Levels of Phosphorus Availability