Residual effect of different levels of organic manures amended Sulphur on nutrients uptake, nutrients-relationships and protein content of rice in a mustard-rice cropping system

Abstract

This study revealed that S application has definite residual effect on succeeding crop rice as evinced by significant increase in N, P and K uptake by rice grain and straw. The mean total uptake of N increased from 60.3 to 106.7 kg ha-1 at 80 kg S ha-1 whereas total P and K uptake increased from 20.2 to 33.5 kg ha-1 and 90.0 to 158.0 kg ha-1 upto 100 kg S ha-1 level. The residual effect of organic manure was apparent in enhancing the mean total uptake of N from 82.1 to 89.8 kg ha-1, total P uptake from 24.7 to 31.1 kg ha-1 and total K uptake from 125.9 to 136.2 kg ha-1. The FYM proved better as compared to BGS in increasing the total N, P and K uptake by rice. The N: S ratio in rice grain and straw was also increased upto 60 kg S ha-1 in grain and 80 kg S ha-1 in straw and beyond that level it decreased with lowest N: S ratio at highest level of S application (120 kg S ha-1). No Significant residual effect of S levels was observed on P: S ratio in rice grain. The N: S ratio of 13.91 and 3.75 was considered as the optimum N: S ratio for rice grain and straw, respectively obtained at optimum treatment combination. The optimum P: S ratio 5.36 for grain and 0.84 for straw were obtained at optimum treatment combination. The mean protein content increased significantly from 5.80 to 8.04 per cent with increasing S levels upto 60 kg S ha-1 beyond which it decreased regularly. Between the organic manures, the residual effect of FYM was found superior over BGS in increasing protein content in rice.