Crop residue: A potential source for bio energy and high value bio-products in India

Farming activities generate huge amounts of crop residues annually worldwide. These residues constitute a large biomass which includes non-edible parts left over after harvest. Crop residue are two types, first are primary residues which are associated with crop production e.g. stalk, husk, bagasse, straw, stover, leaves and roots. While secondary residues are by products of processing and comprise of e.g. seed, skin, rind, and pomace, pit, shell, peeling, husk, and bagasse. Crop residues are valuable resource and primary material for secondary agriculture and we can protect the environment as well as reduce pollution in the biosphere by its eco-friendly disposal. Ministry of New and Renewable Energy estimated that about 500 Mt of crop residues are generated annually in India. Among different crops, Cereal crops (rice, wheat, maize, millets) contribute 70%, while rice crop alone contributes 34% Sugarcane residues consisting 2% of the crop residues in India. Traditionally, crop residue has been used as animal feed, domestic fuel, packaging material, roof thatching, soil mulching and bedding material. Now via novel ways it can be used for preparation of diverse products viz., fortified livestock feed, compost, biofuel, bio-oil production, bio-refinery based biochar production for its efficient utilization. We have to promote its use as a raw material for secondary agriculture. Amongst the various technologies, anaerobic digestion is a fascinating process for the recovery of nutrients and renewable energy from various agriculture residues and an important way for handling waste. These technologies not only enhance its use efficiency but also promote new ventures for entrepreneurs.