Influence of sulphur on yield and mineral nutrition of crops in maize-wheat sequence.

The direct effects of applied S on maize and residual effects on wheat were evaluated at two sites for two years in maize-wheat cropping system. Application of S up to 40 kg ha−1 enhanced the average grain yield of maize by 9.9 q ha−1. The residual value of 40 kg S ha−1 increased the wheat grain yield by 5.4 q ha−l. On fitting the average grain yield data of two years into quadratic equation, the optimum dose of S for maize was found to be 53 kg S ha−1 providing 35.06 q ha−1 grain yield. Sintilariy, the optimum dose of S for wheat appeared at 49 kg S ha−1 giving 32.93 q ha−1 grain yield Similar trend in yield response of stoverl straw was also recorded. Total S uptake progressively increased from 2.58 to 9.44 kg ha−1 in maize and from 8.05 to 13.22 kg ha−1 in wheat. A phenomenal increase in Nand K uptake was recorded in both the crops due to rising S levels. The N:S ratio in both the crops progressively decreased with increasing S levels. This ratio at 40 kg S ha−1 level was 19.0 and 11.4 in maize grain and stover as well as 18.0 and 10.3 in wheat grain and straw, respectively. Crude protein content was increased from 9.2 to 10.7 per cent in maize and 12.4 to 13.2 per cent in wheat grains up to 40 kg S ha−1 level.