Abstract

Estimating site and depth wise distribution of major (S) fractions and their relationship with soil physicochemical properties are central to developing efficient S management strategies, especially in S deficient areas. Screening use of efficient genotypes also holds promise in this regard in environment like low land paddy ecosystem, which are known to be extremely hostile in the term of S availability for crop uptake. In the present investigation, distribution of total, organic, heat soluble, 0.15% calcium chloride extractable and sodium di-hydrogen phosphate extractable S were studied in a Inceptisol on one hand, while trying to screen a lowland paddy genotype with higher S uptake efficiency on the other. A wide horizontal variation in total S(261 to 670 mg kg^-1) was observed in surface soil. Different S fraction was positively correlated with soil organic carbon and clay content, whereas negative correlation of the S fraction was recorded with pH and calcium carbonate equivalent. Organic- S was the dominant fraction throughout the profile although its contribution to total S pool declined with depth. Irrespective of location and soil depth, sodium di-hydrogen phosphate extracted greater amount of S in comparison to heat soluble and calcium chloride extractable S. Paddy variety PD-4 performed better over the other in the term of growth, yield and nutrient uptake. Remarkable improvement in growth, yield and nutrient response of paddy was recorded to S application upto 40 kg ha^-1.

Key words: Sulphur, paddy soils, soil physicochemical properties, growth, yield, nutrient uptake.