Influence of silicon and nitrogen fertility rates on rice (Oryza sativa L.) yield and uptake

Abstract

Negative impacts of excessive nitrogenous fertilizers could be minimized by the use of silicon. In order to study the effects of silicon and nitrogen on rice yield and uptake, a field experiment was conducted in two phases. Initially Si concentration in rice index leaves and available silicon status accessed and found low status of available silicon (73.62 to 96.41 kg ha-1) content. As well as, the mean Si concentration in rice index leaves also low, ranged from 1.54 to 3.15 per cent with an overall mean of 2.48 per cent. The grain yields ranged from 2653 to 6860 kg ha-1 with a mean of 5624 kg ha-1 and both were exerted a significant positive correlation (r = 0.55**). Based on these results, second phase of field experiment was conducted with sixteen combinations of Si and N with high Si (JGL-3855) and low Si (RNR-2354) content genotypes in strip plot design. Conjunctive application of N and Si to both genotypes, JGL-3855 recorded significantly higher grain and straw yields, nutrient content and total uptake compared to RNR-2354. Among the different combinations of Si and N, application of 160 kg N + 600 kg Si ha-1 recorded significantly higher grain and straw yields, nutrient concentration and total uptake over control N0 + Si0 and was on par with N160 + Si400, N160 + Si 200, N120 + Si600, N120 + Si400 and N120 + Si 200.