Tamil Nadu Agricultural University, Coimbatore, 641 003
1Present address: Department of Agronomy, Central Agricultural University, Iroisemba, Imphal 795 004
A field experiment was conducted at Coimbatore during the rainy (kharif) season of 1999 and 2000, to study the effect of different water- and nitrogen-management practices on hybrid ‘ADTRH 1’ rice (Oryza sativa L.) in clay-loam soil. The maximum yield of grain and straw were recorded with irrigation on the day of disappearance of ponded water which remained on a par with that obtained with irrigation 1 day after disappearance of ponded water. Among the nitrogen-management practices, significantly highest grain and straw yields were observed with recommended dose of 150 kg N/ha applied in 4 splits along with green manure. Similar trend was recorded for number of panicles, spikelets and filled grains while spikelet sterility and single grain weight remained unaffected by irrigation treatments, but showed a marked reduction of 2.0 to 2.5% at N3>N1>N2 levels over N0. Thus application of N in 3 or 4 splits helped reduce spikelet sterility and also improved grain weight significantly. The N uptake was significantly enhanced by the irrigation regimes with irrigation on the day of disappearance, and 1 day after disappearance of ponded water, being equally effective. Application recommended dose of N in 4 splits + green manure and 4 splits in different ratios were found equally effective in terms of nitrogen uptake. Higher agronomic efficiency was recorded with irrigation on the day of disappearance along with 4 splits of N + green manure and SPAD (spall out) basis of nitrogen application. Maximum water-use efficiency was obtained with wider irrigation interval at 3 days after disappearance of ponded water along with the 4 applications of N + green manure.
Irrigation, Split application of N, Rice hybrid
