Influence of Time of Planting, Spacing, Seedling Number and Nitrogen Management Practices on Productivity, Profitability and Energetics of Rice (Oryza sativa) in Island Ecosystem
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Author:V. Damodaran, B.K. Saren, N. Ravisankar and N. Bommayasamy
p-ISSN:0024-9602, e-ISSN:2582-5321, Vol:99, Issue:jul-sep
DOI: https://doi.org/10.29321/MAJ.10.100134
Abstract
Field experiments were conducted during wet season of 2007 and 2008 at Central Agricultural
Research Institute, Port Blair, Andaman and Nicobar Islands in order to evaluate the practices
of System of Rice Intensification (SRI) in Island ecosystem. Time of planting, spacing and
nitrogen management practices significantly influenced the growth and yield attributes while
number of seedlings/ hill did not exert any influence on these parameters. Planting in second
fortnight of June with 20 x 20 cm spacing recorded higher number of tillers (18.3), DMP (17.6),
panicles/m 2 (9.2) and filled grains/panicle (9.1). As a result of better growth and yield
components, higher grain yield (4,678 kg/ha), net returns (Rs. 31,768/ha), net return per rupee
invested (1.47) and energy ratio (14.5) were recorded in the early planting. Application of 100
% Recommended Dose of Nitrogen (RDN) through urea recorded more number of tillers with
higher DMP, number of panicles, more number of filled grains and highest grain yield of 4,465
kg/ha but it was comparable with 50 % RDN through Gliricidia + 50 % RDN through urea and 75
% RDN through Gliricidia + 25 % RDN through urea. Though the net return was slightly higher
(Rs. 29,002/ha) with application of 100 % RDN through urea, but net return per rupee invested
was higher (1.40) with application of 50 % RDN through Gliricidia + 50 % RDN through urea.
Thus, planting in second fortnight of June with 20 x 20 cm spacing using single seedling
combined with application of 50 % N through Gliricidia and 50 % N through urea can be
recommended for achieving higher productivity, profitability and energetic of rice in island
ecosystem.
Key words : Rice, productivity, profitability, energetics, island ecosystem