Energy Dynamics of Aerobic Rice Cultivation in India

Aerobic rice needs 30% less total water for land preparation, 50% saving on labour requirement and 50% less GHG emission compared to transplanted rice. Energy use efficiency of aerobic rice cultivation also varies due to varieties. However, a detailed study on various energy inputs components of aerobic rice cultivation (variety, water management, spacing, fertilizer dose and weed management) is lacking. To confirm the energy dynamics of aerobic rice cultivation, a combined study was taken up to find out the energy input, output and energy use efficiency of aerobic rice cultivation consisting of various trials conducted at research farm of ICAR-Indian Institute of Rice Research and few other trials conducted at other places. Gayatri variety performed well in terms of higher energy use efficiency at eastern part of India. Further higher energy use efficiency (output/input ratio) was recorded at 100% RFD. Crop spacing also affects the total energy output of aerobic rice. It was seen that the total output energy is highest at optimum spacing of 20 x 10 cm compared to 25 x 10 and 30 x 10 cm. Apart from need based hand weeding, Pendimethalin 1.0 kg /ha + Bispyribac sodium 35 g/ha resulted higher energy use efficiency (2.75) compared to those of other chemical weed management practices. It was observed that aerobic rice based systems maintained higher productivity and profitability in comparison to transplanting based rice cropping systems. The study revealed that varieties, fertilizer dose and spacing played crucial role in enhancing the energy use efficiency of aerobic rice cultivation. So, farmers have to strike a balance among the input resources specially variety, water, fertilizer to achieve higher energy use efficiency in aerobic rice based cropping systems.