Crop residues as soil amendments and feedstock for bioethanol production.
Traditional solid fuels account for more than 90% of the energy supply for 3 billion people in developing countries. However, liquid biofuels (e.g., ethanol) are perceived as an important alternative to fossil fuel. Global crop residue production is estimated at about 4 billion Mg for all crops and 3 billion Mg per annum for lignocellulosic residues of cereals. One Mg of corn stover can produce 280L of ethanol, compared with 400L from 1Mg of corn grains; 1Mg of biomass is also equivalent to 18.5GJ of energy. Thus, 3 billion Mg of residues are equivalent to 840 billion L of ethanol or 56x10(9)GJ of energy. However, removal of crop residues exacerbates soil degradation, increases net emission of CO2, and aggravates food insecurity. Increasing the SOC pool by 1 Mg C ha(-1)yr(-1) through residue retention on soil can increase world food grain production by 24-40 million Mg yr(-1), and root/tuber production by 6-11 million Mg yr(-1). Thus, identifying alternate sources of biofuel feedstock (e.g., biofuel plantations, animal waste, municipal sold waste) is a high priority. Establishing biofuel plantations on agriculturally marginal or degraded lands can off-set 3.5-4 Pg Cyr(-1).
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Carbon Management and Sequestration Center, The Ohio State University, Kottman Hall, 2021 Coffey Road, Columbus, OH 43210, USA. LAL.1@osu.edu
D000818:Animals; D018533:Biomass; D002244:Carbon; D018556:Crops, Agricultural; D004736:Energy-Generating Resources; D000431:Ethanol; D008372:Manure; D006109:Poaceae; D012987:Soil; D014866:Waste Products
D008372:Manure; D012987:Soil; D014866:Waste Products; D000431:Ethanol; D002244:Carbon