Integrating energy input–output analysis with APSIM simulations to evaluate energetics and soil-mediated water productivity of major pulse crops across India

Energy use efficiency is a key indicator of sustainability in pulse-based agricultural systems. This study evaluated the energy input–output performance of five major pulse crops of India—chickpea, redgram, lentil, greengram, and blackgram-across representative pulse-growing districts using standard energy equivalents and APSIM simulations. Total energy input ranged from 4579 MJ ha −1 in greengram to 10,048 MJ ha −1 in lentil, while energy output varied considerably across crops and regions. Redgram recorded the highest mean total energy output (110,346 MJ ha −1 ), net energy (101,868 MJ ha −1 ), and energy use efficiency (13.02). Lentil showed the lowest efficiency (5.02) and the highest specific energy (8.30 MJ kg −1 ). Chickpea exhibited relatively low specific energy (3.93 MJ kg −1 ) and stable performance under semi-arid conditions. Significant spatial variability in energy indicators reflected regional differences in climate and management practices. Overall, redgram and chickpea emerged as energetically superior pulse crops under Indian conditions. Quadratic regression analysis of the water use-yield relationship revealed crop-specific optima, with redgram requiring 600–900 mm seasonal water use for maximum yield, whereas chickpea, greengram, lentil, and blackgram showed optima between 100 and 550 mm. These findings highlight the importance of region-specific crop and water management strategies to improve productivity, energy efficiency, and sustainability in pulse-based cropping systems.