Influence of prickly sesban (Sesbania cannabina) intercropping in wet-seeded rice (Oryza sativa) on productivity, profitability, energetics and nitrogen balance under island ecosystem

Abstract

Experiments were conducted during 2005 and 2006 at Port Blair, to evaluate prickly sesban [Sesbania cannabina (Retz.) Pers.] intercropping in wet-seeded rice under island ecosystem. The results revealed that though rice + dhaincha or prickly sesban registered higher yield when dhaincha is incorporated mechanically with cono weeder (4.24 tonnes/ ha), it is on par with manual and manual + conoweeder incorporation. In terms of economics and energetics, rice+ dhaincha incorporation using cono weeder recorded higher net returns (Rs 15 876/ha) and higher energy ratio (8.38). Significant increase in available soil N was observed at harvest in rice + dhaincha (254.7 kg/ha) compared to sole rice (226.8 kg/ha). N loss was maximum in sole and unweeded conditions compared to rice + dhaincha incorporation through manual or conoweeder or its combination.