Energy budgeting of colocasia-based cropping systems in the Indian sub-Himalayas

This study examines the energy requirement and energy input output relationship of colocasia-based cropping systems viz., Colocasia-onion-frenchbean, colocasia-gardenpea-frenchbean, colocasia-wheat-okra, colocasia-radish-potato, colocasia-cabbage-frenchbean, colocasia-coriander-cauliflower-frenchbean, colocasia-corinder-tomato and rice-wheat in the Indian Himalayas. Results revealed that potato consumed the highest total input energy (25084 MJ/ha) and the least was in coriander (5108 MJ/ha). System productivity in terms of colocasia equivalent yield was highest with colocasia-onion-frenchbean system (52.38 t/ha). Mineral fertilizers (50-62%), seed (8-26%) and irrigation water (11-17%) consumed the bulk of the input energy for all cropping systems. The total input energy was highest under colocasia-radish-potato (59919 MJ/ha) and the lowest in rice-wheat (38244 MJ/ha). Colocasia-onion-frenchbean, with the highest system productivity, produced the highest energy productivity (1.203 kg/MJ). Colocasia-coriander-tomato, with the highest system biomass, produced higher energy ratio (30.4), human energy profitability (2813.4) and energy profitability (29.43). Colocasia-wheat-okra (1362928 MJ/ha) recorded the highest total energy output. Human energy profitability was highest under colocasia-coriander-tomato (2813.4) indicating that it was the most labor energy efficient cropping system. Hence, the colocasia-corinder-tomato and colocasia-onion-frenchbean cropping systems are more suitable in the Indian Himalayas for their higher energy use efficiency and energy productivity, respectively, and are advised for wide adoption. (C) 2012 Elsevier Ltd. All rights reserved.