Indian Journal of Agronomy

Sulphur (S) deficiency in rice (Oryza sativa L.)–wheat (Triticum aestivum (L.) emend. Fiori & Paol) growing areas of Garhwal region of Western Himalayan zone was delineated during 2003–2007. For this, 1191 soil samples (0–15 cm depth) were collected from Fakot and Chamba Agricultural Development Blocks (ADBs) of New Tehri Districts and analyzed for soil OC and available S content. Of the total, > 40% soils were low in OC content and occurrence of S deficiency was also associated with soil OC content. On S deficient soils of village Jajal (Fakot, ADB) and village Nagini (Chamba, ADB), on-farm experiments were conducted during 2004 to 2007 with four levels of S (0, 15, 30 and 45 kg S/ha) in a randomized block design under rice-wheat system. Rice yield increased (p<0.05) by 1.15 to 1.42 t/ha at Jajal and 1.14 to 1.55 t/ha at Nagini with 30 and 45 kg S application over no-S application in different years. Succeeding wheat yields also increased (0.66 to 1.27 t/ha and 0.41 to 1.16 t/ha, respectively) under residual S (30 or 45 kg S/ha) plots. Whereas, lower S application dose (15 kg/ha) did not leave residual effect on the succeeding wheat crop. Compared with (no-S), cumulative rice-wheat system S uptake at 30 and 45 kg S/ha was also higher by 102% to 134% at Jajal and 90% to 123% at Nagini. Skipping S application or under application of 15 kg S in fertilization schedule caused depletion in available S content of the soils by 1.0 to 2.7 mg/kg over initial S status at these study sites. After 03-crop cycles, apparent S balance was positive (10 to 57.3 kg/ha at Jajal and 14.7 to 67.0 kg/ha at Nagini) when rice received external fertilizer S input. On an average, value cost ratio (VCR) for rice-wheat system due to S fertilization ranged between 59 to 107/invested in S at Jajal and 48 to 101/invested in S at Nagini indicating the necessity of inclusion of S in fertilization schedule for sustained yield and profit of rice-wheat system in Garhwal region.