No abstract

A field experiment was conducted during wet and dry seasons of 1987–88 and 1988–89 to evaluate the performance of green manures with and without fertilizer nitrogen in lowland rice and their residual effect on succeeding crop of chickpea grown under rice‐chickpea cropping system. Incorporation of Ipomea carnea (green leaves), Cassia tora and Parthenium hysterophorus (green young plants) ca. 5 t/ha fresh weight significantly improved yield and yield components namely panicles per hill, panicle length, grains per panicle and test weight of transplanted rice. The results showed that at least 20 kg/ha fertilizer nitrogen applied to rice could be replaced by incorporation of 5 t/ha fresh weight green manure. Supplementation of 60 kg N/ha through urea to the green manures treated plots proved to be the best in respect of grain yield and was comparable to the yield obtained under 80 kg N/ha as urea alone. Plant N‐uptake followed the similar pattern of rice grain yield. Residual fertility in terms of available nitrogen increased under the green manure treatments, whereas urea nitrogen alone made no impact on fertility build‐up. Green manures showed significantly higher residual response than fertilizer N alone to seed yield and N uptake of chickpea.