Direct and Residual Effect of S on Productivity, Protein Content and Nutrient Uptake in Wheat under Aerobic Rice-Wheat Cropping System

Abstract

A field experiment was conducted during Rabi (November-April) seasons of 2010-11 and 2011-12 at the research farm of the Indian Agricultural Research Institute, New Delhi to study the direct and residual effects of sulphur application on productivity, protein content, nutrient concentration and uptake in wheat grown under aerobic ricewheat cropping system. The experiment was laid out in a randomized block design for first aerobic rice and split plot design for succeeding wheat and second cycle of aerobic rice-wheat sequence. Five treatments comprising of combinations of two S sources i.e. gypsum and phosphogypsum and three S levels, i.e. 0, 30 and 60 kg S ha1, were taken in aerobic rice. And in succeeding wheat, each main plot was split into three sub plots for application of elemental sulphur at three levels, i.e. 0, 15, and 30 kg S ha-1 and replicated thrice. Application of sulphur, on an average, increased the wheat grain yield by 10%. Both the S levels resulted in significantly higher grain, straw and biological yields of wheat over the control during both the years. Averaged across two years, application of 15 kg S ha-1 and 30 kg S ha-1 increased the grain yield of wheat by 8.4 and 11.6 %, respectively, over the control (no sulphur). Though highest yields (grain, straw and biological) were obtained with 30 kg S ha-1, but significant response was observed only up to 15 kg S ha-1, except in biological yield during 2010-11. Protein content in wheat grain improved significantly with S application. Application of sulphur at either of the levels (15 and 30 kg ha-1) resulted in significant increase in concentration of N, P, K and S in wheat grains. The residual effects of sulphur sources and levels applied to preceding rice were observed non-significant on N, P, K and S concentration in grain and straw of succeeding wheat during both the years of study. Irrespective of the levels (15 or 30 kg S ha-1), application of sulphur significantly increased the uptake of N, P, K and S by grain, straw and its total of wheat.