Status of Available Sulfur in Soils of North-Western Indo-Gangetic Plain and Western Himalayan region and Responses of Rice and Wheat to Applied Sulfur in Farmer's Fields

Widespread nutrient deficiencies have emerged as the major soil-related constraints, with sulfur (S) being one among them, for sustaining rice-wheat productivity in many parts of the north-western Indo-Gangetic Plain (IGP) and the Western Himalayan region (WHR). Therefore, soils from different agricultural development blocks (ADBs) of Meerut and Jyotiba Phule Nagar (J.P. Nagar) Districts in the Upper Gangetic Plain (UGP) zone, Sonipat, and Panipat Districts in Trans-Gangetic Plain (TGP) zone, and New Tehri District in Garhwal zone of WHR were analyzed for their available S-status. Farmers' fertilizer management practices revealed that fertilizer use was highly unbalanced, and use of S fertilizers was generally negligible. Deficiencies of S were noticed in 19-47 % of the soil samples. On-farm experiments at these sites showed that rice (Oryza sativa L.) yields improved by 0.84-1.90 t ha(-1) with the additions of 30-45 kg S ha(-1) on S-deficient soils of IGPs, whereas the crop response varied from 1.16 to 1.39 t ha(-1) on WHR soils. Also, the residual effect of 30-45 kg S ha(-1) was noticed in succeeding wheat (Trititicum aestivum L.). Averaged over S rates, 37-49 % of the applied S was recovered in the system at different locations. Skipping S application decreased the available S content of the soils (0.6-2.4 mg kg(-1)) compared with initial content. Substantial yield gain and economic returns due to the use of S suggested for inclusion of S in the fertilizer schedules for these soils.