In Tamil Nadu, rice is the most important food crop grown in 2.08 million hectares usually grown in flooded soils and consumes 80 per cent of the available irrigation sources of the State with a poor Water Use Efficiency . This traditional practice resulted in huge amount of water loss through seepage/deep percolation. Hence attention was focused on efficient water management practices for rice without sacrificing the yield levels. Moreover there is huge gap exists in WUE between the experimental farm (0.5-0.7 g / lit of water) and farmers holding (0.2 g / lit of water). It is proved beyond doubt that with perfect land levelling and weed control, maintenance of field capacity (just moist) moisture is the best proposition for rice crop. Adaptive Research Trials (ARTs) are one of the components where proven water management technologies can be tested in farmers" holding. The fields selected for conducting ARTs (totally 150) represented different category of farmers, locations, soil types and agro-ecological situations. Besides the proven water management techniques as applicable to the different site-specific situations, various component technologies were also included in the treatments. The researchers" method and farmers" conventional method of irrigation practices were evaluated each in half-acre plots. The water used was low (1003 mm) in the plot with improved technologies as against 1234 mm with continuous submergence registering a saving of 20.11 per cent and Water Use Efficiency (WUE) of 5.9 kg ha-1 mm-1 in the plot with improved technologies. A Benefit Cost ratio of 2.61 in the plot with improved technologies obtained as against 2.23 in the continuous submergence.

    作　　者：P. DEVASENAPATHY, K. PALANISAMI, B. CHANDRASEKARAN, and J. BHUVANESWARI；
    作者单位：Water Technology Centre, Tamil Nadu Agricultural University；
    论文来源：水稻可持续生产——政策、技术与推广国际会议（中国杭州，2004年）。