Evaluation of safe alternative wetting & drying and its influence on growth, yield and water use of the efficiency of rice (Orzya sativa l.)

Abstract

Due to the increase in scarcity of freshwater resources available for irrigated agriculture and escalating demand for food around the world, in the future, it will be necessary to produce more food with less water. Due to inadequate or unevenly-distributed rainfall, irrigation is essential to high rice yields. A field experiment of Alternative Wetting and Drying Irrigation (AWDI) was con-ducted during kharif season 2014 & 2015 at Soil & Water Management Research Institute, Tamil Nadu Agricultural University, Thanjavur, Tamil Nadu, India. The treatments ranged from delayed irrigations of T1 to T6 (10, 15, 20 cm depletion of water level below the ground level, 15cm depletion of water up to maximum tillering, up to panicle initiation & up to 10 days prior to harvest) and continuous submergence (T7) of field irrigation water denoting the application of 5 cm flooded water condition, when the water level in the perforated PVC pipe fell at 10, 15 and 20 cm below ground level respectively. There was a significant (5% level) conse-quence of plant height, productive tillers, filled grains, yield and Water Use Efficiency (WUE) due to the influence of AWDI. The highest yield (5981 kg/ha) and WUE (7.56 kg/ha/mm) was recorded in treatment T1. Longer water stress resulted in the loss of grain yield to the tune of 500 to 1000 kg/ha. This study found that in sandy loam soil at 10cm depletion of ponded water produced maximum yield (5809 kg/ha, besides the highest B.C ratio of 2.02) and WUE (7.56 kg/ha mm).