Abstract:
Field experiment was conducted during wet and dry seasons of 2007-09 at Field Crops Research Farm of Central
Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands to evaluate System of Rice
Intensification (SRI) in rice and its residual effect on groundnut in rice (Oryza sativa L.) – groundnut (Arachis
hypogaea L.) systems. Time of planting, spacing and nitrogen practices evaluated significantly influenced the yield
attributes and yield of rice, while the residual effect of N management practices had a positive influence on the yield
attributes and yield of succeeding groundnut. Early planting in second fortnight of June with 20 cm × 20 cm spacing
recorded higher panicles/m2 (9.1 %), higher number of filled grains/ panicle (108), higher grain yield (4 678 kg/ha),
about 3% higher REY, productivity (26.8 kg/ha/day), and total profitability (` 62 882/ha) compared to the same time
of planting with wider spacing (25 cm × 25 cm). Though application of 100% Recommended Dose of Nitrogen
(RDN) through urea recorded highest grain yield (4 465 kg/ha) of rice, it was comparable with 50% RDN through
Gliricidia + 50% RDN through urea and 75% RDN through Gliricidia + 25% RDN through urea. Application of
50% RDN through Gliricidia + 50% RDN recorded nearly 6% higher REY and ` 6 565/ha more profitability higher
output energy in rice-groundnut sequence compared to application of 100% RDN through urea. N management
practices of rice, in the crop sequence of rice- groundnut were found to improve the soil nitrogen status. Early
planting of rice in second fortnight of June at 20 cm × 20 cm with the application of 50% RDN through Gliricidia +
50% RDN through urea can be recommended for achieving higher productivity, profitability and energy use efficiency
of rice - groundnut system in Island ecosystem.
Key words: Energetics, Island ecosystem productivity
