DIRECT AND RESIDUAL SUPPLY OF AVAILABLE ) SULPHUR AND ITS BALANCE SHEET IN RICE-RICE CROPPING SEQUENCE

摘要

A field experiment was conducted during Kharif 2001 to study the direct and residual supply of S from different sources and its effect in rice-rice sequence. The dry matter production increased with stages in the both first and second crops and was maximum at 40kg S ha~(-1) and declined at 60 kg S ha~(-1). Sulphur availability in both the crops increased with S levels and decreased with advancement of crop growth and the highest S availability was noticed at 60kg S ha~(-1). Among the organics, Sesbania aculeata consistently increased the dry matter production at all stages in the first crop but in residual crop, sulphitation pressmud registered the highest dry matter production. However S availability was highest in both crops in sulphitation pressmud amended soil. Increase in S build up was noticed in residual plots and was more when organics were applied. The highest S build up was observed in soil amended with sulphitation pressmud and 20kg S ha~(-1).