Sweet Sorghum: a Pro-Poor Bioethanol Crop.

Serious critiques have been leveled against bioenergy crops due to competition with food (maize), motivating expansion into environmentally-sensitive ecosystems (oil palm and sugarcane into forest areas), questionable net greenhouse gas savings (crops replacing forest and peatland), high water requirement (sugarcane), and/or heavy dependence on fossil fuel-driven mechanization and high nitrogen fertilizer rates. Sweet sorghum in the developing world appears less vulnerable to these critiques, though more detailed analysis is needed. Often overlooked are potential benefits to the poor, who may gain from increased crop prices. Sweet sorghum yields food, feed and ethanol, and its demand for human food use is declining, reducing food-fuel competition issues. If increased crop value motivates the adoption of yield-enhancing technologies such as fertilizer and hybrids, yields could even increase substantially, reducing land competition concerns. Sweet sorghum grows best in moderate-rainfall cereal agro-ecosystems that are generally considered to be less environmentally-sensitive than the areas sown to sugarcane, oil palm and maize. Sweet sorghum in the developing world is largely dependent on manual labor at lower fertilizer rates, providing employment opportunities while reducing fossil fuel inputs into the production system. Current priorities for research and development include i) modes of social organization including public-private-farmer partnerships that are mutually beneficial and motivating to all parties; ii) organizing logistical, production and marketing chains involving thousands of small, poor farmers that are efficient, profitable, and competitive with large mechanized farms, iii) solving the harvest-time bottleneck for rapid juice extraction and fermentation under mechanization constraints typical in developing countries, iv) developing more productive cropping system components such as improved soil fertility, hybrid varieties and molecular/transformation technologies to increase ultimate ethanol yields per hectare; and v) analysis of net greenhouse gas emissions and net energy balance under developing-world cultivation conditions, devising ways to maximize environmental benefits.