Yield, Nutrient Uptake and Economics of Aerobic Rice under Different Irrigation Regimes and Cultivars

Transplanted rice is the traditional rice cultivation consumes more water, which threatens the sustainability of rice production. Thus, there is a need to find out the alternate means of rice cultivation to save water and other inputs. A field experiment was conducted during the summer seasons of 2019 and 2020 in the West Central Table Zone of Odisha to evaluate the efficacy of medium-duration rice varieties under varying irrigation regimes in aerobic conditions. The experiment followed a split-plot design with four irrigation regimes ( IW/CPE ratios of 1.0, 1.5, 2.0, and 2.5) as main plots and four rice varieties (Naveen, MTU-1010, CR Dhan-201, and CR Dhan-204) as subplots. The irrigation regime at IW/CPE = 2.5 recorded the maximum grain yield of 4.07 t/ha, which was significantly superior to the other irrigation regimes, but statistically at par with IW/CPE = 2.0 (3.90 t/ha). Among the cultivars, the variety CR Dhan-201 produced the higher grain yield (3.54 t/ha), which was significantly higher than the other varieties, but at par with Naveen (3.30 t/ha). Maximum nutrient uptake was observed at the IW/CPE = 2.5 irrigation level, with uptake values of 80.07 kg N/ha, 36.70 kg P/ha, and 124.4 kg K/ha, all of which were significantly superior to other irrigation regimes. Similarly, the variety CR Dhan-201 exhibited the higher nutrient uptake, recording 65.41 kg N/ha, 30.49 kg P/ha, and 104.8 kg K/ha, significantly superior than the other cultivars/varieties. The maximum FWUE was observed under IW/CPE = 1.5, with a value of 40.71 kg/ha-cm, which was at par with other irrigation regimes except IW/CPE 2.5 whereas, B: C ratio (1.74) was observed with irrigation at IW/CPE 2.0 which was at par with IW/CPE 2.5 (1.73)and significantly superior to other irrigation regimes. Among the varieties, CR Dhan-201 recorded the higher B:C ratio of 1.62 & higher FWUE of 41.60 kg/ha-cm which was significantly superior to the rest other cultivars.