Productivity, nutrient uptake and profitability of winter season rice (Oryza sativa) varieties as influenced by alternate wetting-drying irrigation and nitrogen management

Abstract

A field experiment was conducted on clay loam soil at Agricultural Research Institute, Rajendranagar, Hyderabad, Telangana, during the winter (rabi) season of 2016–17 and 2017–18, to identify optimum scheduling of alternate wetting and drying irrigation (AWD) under different nitrogen levels on rice (Oryza sativa L.) varieties. The treatments consisted of 3 irrigation regimes, i.e. recommended submergence of 2 to 5 cm water level, AWD irrigation when water level falls below 3 cm from soil surface in perforated pipe, AWD irrigation when water level falls below 5 cm from soil surface in perforated pipe, as main plot treatments; 3 nitrogen levels (120, 160 and 200 kg N/ha) as subplot treatments; and 2 rice varieties (‘KNM 118’ and ‘JGL 18047’) as sub-subplot treatments laid out in a split-split plot design with 3 replications. There was no significant difference in terms of growth, yield attributes, yield, nutrient uptake and economics between rice varieties ‘KNM 118’ and ‘JGL 18047’ with continuous submergence, and alternate wetting and drying irrigation under different nitrogen levels during the winter (rabi) season. Irrigation maintained at recommended submergence of 2 to 5 cm water level resulted in higher growth parameters, yield attributes, grain yield (7,123 kg/ha), straw yield (8,045 kg/ha), nutrient uptake and net returns (`57,202/ha), which were comparable with AWD irrigation when water level falls below 3 cm from soil surface in perforated pipe. Application of 200 kg N/ha ensued higher growth parameters, yield attributes, grain yield (7,086 kg/ha), straw yield (7,907 kg/ha and net returns (`57,247/ha), which were at par with 160 kg N/ha.