Abstract

The present investigation was carried out to study the effect of integrated nutrient management on rice yield and sulphur transformation in soil into its various chemical pools in an on-going long-term fertilizer experiment initiated during kharif 1991 at research farm of CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur. Nine treatments comprising control, inorganics viz., 50 and 100% NPK and conjoint use of 50 and 75% NPK with 50 and 25% N substitution either through FYM, wheat straw or green manure, Sesbania aculeata (Dhaincha) to rice (June-October) followed by 100 and 75% NPK through inorganics to wheat (November-May), respectively, were imposed since the inception of the experiment. Different S fractions were estimated in surface soil samples after the harvest of wheat (June, 2011). Data in respect of grain and straw yield of rice and different soil properties were also recorded for two years (2010 and 2011). The results of surface soil samples (0–0.15 m) collected after the harvest of wheat showed that zero fertilization led to decline in the levels of all the S forms, while application of sulphur containing fertilizer and organics increased it over control. Organic sulphur was found to be the most dominant fraction (about 96%) followed by heat soluble sulphur. Integration of chemical fertilizers with organics proved better as compared to application of chemical fertilizers alone. Integrated use of inorganic fertilizers in conjunction with organics increased pH, organic carbon, CEC, rice grain and straw yields over inorganically treated plots. Highest grain and straw yield of rice was recorded when 50% N was substituted through FYM. Pre-transplant incorporation of 50% N through FYM produced 76.7 q/ha rice grain yield which was statistically at par with yield obtained under its 25% N substitution.