Efficient use of energy inputs in rainfed pearl millet

Abstract

The paper summarizes the results of four field trials aimed to gauge, quantify and determine relationships between various energy inputs and output to augment pearl millet productivity and energy use efficiency. Application of 40 kg N ha −1 with one manual weeding involving 8034 MJ ha −1 total energy input resulted in 72% increase in grain production, and a total energy output of 39 817 MJ ha −1 compared to 27 226 MJ ha −1 output without nitrogen. The nitrogen accounted for 12 591 MJ and the weeding for 21 886 MJ ha −1 energy output. Combined application of these resulted in complementarity of 15.5% over effect of individual input. The least specific energy of 1.76 MJ kg −1 biomass with the highest energy output per unit input (7.45) was recorded by the application of 40 kg N ha −1 together with herbicide application. Energy output per unit of energy input varied with the cultivars, BJ 104 being the most efficient. Intercropping grain legumes with pearl millet increased the total crop productivity as well as the energy output. The intercrops clusterbean, dewgram and greengram, with only 91 MJ ha −1 extra energy input resulted in 7938, 3810 and 2215 MJ ha −1 additional energy output, respectively. The energy output between the paired and uniform-row planting with the same plant populations in a good rainfall year was similar, while in a subnormal rainfall year the paired planting gave significantly higher energy output.