Productivity and Water Usage of Rice as Influenced by Different Cultivation Systems

Field experiments were conducted during summer and kuruvai 2008 to study the performance of different rice cultivation methods on productivity and water usage using hybrid CORH-3 as test crop with treatments consisted of different rice cultivation methods viz., transplanted rice (conventional), direct sown rice (wet seeded), alternate wetting and drying method (AWD) (irrigation at two days after disappearance of ponded water), system of rice intensification (SRI) and aerobic rice cultivation. Results revealed that maximum number of tillers/m2, higher shoot and root length at maturity were recorded under system of rice intensification (SRI) followed by transplanted rice, while, aerobic rice produced lower growth parameters in both the seasons. SPAD values at flowering was higher under system of rice cultivation in two seasons studied (42.74 and 39.48 respectively during summer and kuruvai seasons) and transplanted rice compared to aerobic rice and alternate wetting and drying method. In both summer and kuruvai seasons, system of rice intensification (SRI) produced higher grain yield (6014 and 6682 kg/ha), followed by transplanted rice (5732 and 6262 kg/ha) while, the lowest grain yield (3582 and 3933 kg/ha) was recorded under aerobic rice cultivation. Under SRI, 5 and 6.7 % increase in grain yield and 12.6 and 14.8 % water saving were noticed compared to transplanted rice respectively during summer and kuruvai seasons. With respect to water productivity, SRI method of rice cultivation registered the highest water productivity (0.43 and 0.47 kg/m3), followed by AWD and aerobic rice cultivation. The conventional rice cultivation and direct sown rice produced lower grain yield per unit quantity of water used