An assessment of the energy requirements of different intensive forage production systems was carried out at the Indian Grassland Fodder, and Agroforestry Research Institute, Jhansi. This included assessment of energy use and output for five intensive crop production systems: (1) sorghum (single-cut)-berseem, (2) cowpea-sorghum (single-cut)-berseem + mustard-maize + cowpea, (3) sorghum (multi-cut)-berseem + oats, (4) guar-oats-maize and (5) sorghum (single-cut)-wheat-fallow. In all the systems, the Napier bajra hybrid (IGFRI-3) was transplanted in regular plots of 50 m · 13 m. Results revealed that the total annual energy use was highest for sorghum (multi-cut)-berseem + oats (36 606 MJ ha )1 ), followed by sorghum (single-cut)-berseem + mustard, sorghum (single-cut)-berseem-cowpea, guar-oats-maize and sorghum (single-cut)-wheat-fallow (for which values were 31 086, 30 449, 29 867 and 25 956 MJ energy ha )1 , respectively). The high value found for sorghum (multi-cut)-berseem + oats might be attributable to the multi-cuts in this system. Energy use by fertilizers represented the major part of the total energy use, amounting to 28-38 % in all treatments, followed by energy used in electricity, machinery, seeds, human labour and farmyard manure (FYM), in case of all with slight increase in input. In sorghum-wheat, energy use by seeds occupied the second position, followed by energy used in electricity, human labour, FYM and machinery ⁄ diesel. Pesticides contributed the least energy utilization in all the treatments. Herbicides were used for the control of weeds. Among the five forage production systems, sorghum (single-cut)-berseem + mustardmaize + cowpea was found to be the most energy efficient, followed by sorghum (multi-cut)-berseem + oats-sorghum (multi-cut), sorghum (single-cut)-berseem-cowpea, guar-oats-maize and sorghum (single-cut)-wheat-fallow. Sorghum (single-cut)-berseem + mustard-maize + cowpea increased the fertility of the soil, resulting in a higher percentage of organic carbon, higher availability of nitrogen and optimal balancing of the C:N ratio in the upper layers of the soil. These intensive crop production systems also maintain the optimum microbial population in the crop root zone. The benefit-cost ratio (B:C ratio) for the most energy-efficient forage production system was 1.37 : 1. However, the highest B:C ratio was found in the sorghum-wheat rotation (1: 1.57).
