ABSTRACT
Agricultural productivity relies upon energy input in the form of improved seeds, fertilizers, chemicals, irrigation and mechanization including management practices. This energy input is crucial for enhancing crop yields and meeting the demands of an ever-growing population. The increasing demand for rice production from an ever-increasing population and the dwindling nature of natural resources as a result of their continuous and excessive use underscore the urgency of studying energy use efficiency and sustainability in rice production. By conducting this experiment, the goal was to assess the yields, economics, and energy use efficiencies in rice. The experiment employed a Randomized Complete Block Design (RCBD) with three replications, comprising ten treatment combinations viz. US-312 + 60:30:20 kg NPK ha-1, US-312 + 0:30:20 kg NPK ha-1, US-312 + 60:0:20 kg NPK ha-1, US-312 + 60:30:0 kg NPK ha-1, US-312 + 0:0:0 kg NPK ha-1, Sukhadhan-2+60:30:20 kg NPK ha-1, Sukhadhan-2+0:30:20 kg NPK ha-1, Sukhadhan-2+60:0:20 kg NPK ha-1, Sukhadhan-2+60:30:0 kg NPK ha-1, Sukhadhan-2+ 0:0:0 kg NPK ha-1. Results revealed that the highest grain yield and yield attributes were obtained from US-312 + 60:30:20 kg NPK ha-1 (4.98 t ha-1) followed by US-312 + 60:30:0 kg NPK ha-1 (4.76 t ha-1), and US-312 + 60:0:20 kg NPK ha-1 (4.54 t ha-1). The highest energy use efficiency of 3.95 was observed under US-312 + 60:30:0 kg NPK ha-1 which was supported by the highest output energy obtained from grain and biomass yield (153 GJ ha-1) and the highest net energy (117 GJ ha-1). The benefit-cost ratio was found highest in US-312 + 60:30:20 kg NPK ha-1 (1.98), signifying its economic viability and potential profitability. In the context of the western mid-hills of Nepal, the rice variety US-312, coupled with a nutrient composition of 60:30:20 kg NPK ha-1 proved to be an optimal selection. This combination demonstrated higher grain yields and noteworthy economic efficiency.
