| Adler P, Del S J and Parton W J. 2007.Net greenhouse gas flux of bioenergy cropping systems using DAYCENT. Ecology Application, 13(8):345-352.Atjay G L, Ketner P and Duvigneaud P. 1979.Terrestrial primary production and phytomass. In: Bolin B, Degens E T, Kempe S, Ketner P(eds). The Global Carbon Cycle. Chichester, UK: John Wiley and Sons. 129-181.Batjes N H. 1996.Total carbon and nitrogen in the soil of the world. Soil Sciences, 47: 151-163.China Renewable Energy Development Strategy Research Group (CREDSRG). 2008. China renewable energy development strategy study series book-volume of biomass. Beijing: China Electric Power Press.Dai D, Liu R H and Pu G Q. 2005. Evaluation of energy production efficiency of biomass based fuel ethanol program. Transactions of the CSAE, 21(11): 121-123. (in Chinese)Dong D D, Zhao D Q, Liao C P, et al. 2008. Energy consumption analysis in life cycle of cassava fuel ethanol production and the advantages of the new technology in energy consumption. Transactions of the CSAE, 24(7): 160-164. (in Chinese)IEA. 2011.World energy outlook 2011. IEA.Elsayed M, Matthews R and Mortimer N. 2003. Carbon and energy balances for a range of biofuel options. Sheffield Hallam University.FAO. 2008. Food and agricultural situation—bioenergy: prospect, risk and chance. Rome.Farrell A E, Plevin R J, Turner B T. et al. 2006. Ethanol can contribute to energy and environmental goals. Science, 311(5760): 506-508.Hao H Y, Deng L K and Du J B. 2009. Discussion on energy comprehensive utilization pattern in cassava fuel ethanol production process. Cereal and Food Industry, 16(4): 30-33. (in Chinese)Hu Z Y, Dai D and Zhang C. 2003. Life cycle assessment on mixed fuel of cassava-based ethanol and gasoline. Journal of Internal Combustion Engine, 21(5): 341-345. (in Chinese)Hu Z Y, Dai D, Pu G Q, et al. 2004. Life cycle energy efficiency assessment of cassava-based fuel ethanol . Journal of Shanghai Jiao Tong University, 38(10): 1715-1718. (in Chinese)Hu Z Y, Pu G Q and Wang C G. 2004. Life cycle assessment on emission of cassava-based ethanol. Automotive Engineering, 26(1): 16-19. (in Chinese)Hu Z Y, Zhang C and Pu G Q. 2004. Life cycle assessment on energyenvironment and economy of cassava-based ethanol and gasoline mixed fuel. Journal of Internal Combustion Engine, 25(1): 13-16. (in Chinese)IPCC. 1996. Climate Change 1995: The science of climate change (Report of Working Group 1): New York: Cambridge University Press, 1996, 4.Joseph F, Jason H, David T, et al. 2008. Land clearing and the biofuel carbon debt. Science, 319 (5867): 1235-1238.National Bureau of Statistics of China (NBS). 2009. China Statistical Yearbook. Beijing: China Statistics Press.Ni J B, Wang W B, Tian K, et al. 2007. A Study on soil organic carbon content change of betula alnoides plantation in hot areas of Yunnan Province. Journal of West China Forestry Science, 36(1):57-60. (in Chinese)Renton R and Dominick V S. 2007. Carbon mitigation by biofuels or by saving and restoring forests? Science, 317: 902.Revin P B. 2001. Carbon balance of sugarcane bioenergy systems. Biomass and Bioenergy, 20(5): 361-370. Schlamadinger B, Spitzer J and Kohlmaier G H, et al. 1995. Carbon balance of bioenergy from logging residues. Biomass and Bioenergy, 8(4):221- 234.Searchinger T, Heimlich R, Houghton R A. et al. 2008. Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land use change. Science, 319(5867):1238-1240.Soil Sciences Academy of Agricultural Chemistry Committee (SSAACC). 1989. Routine analysis methods of soil agricultural chemical. Beijing:Science Press.Thu L T N, Shabbir H G, Heewala, et al. 2007. Energy balance and GHGabatement cost of cassava utilization for fuel ethanol in Thailand. Energy Policy, 35, 4585-4596.Tropical Research Institute. 2008. Some biofuels are worse environmentally than fossil fuels. Science Daily, 2008-01-03.Wei Z Y, Qi Z P and Li K M. 2007. Soil nutrition and countermeasures of cassava plants in Wuming. Journal of Anhui Agricultural. Science, 35(32):10385-10387. (in Chinese)Wuming Bureau of Statistics (WBS). 2008. Wuming Statistical Yearbook. Wuming: Statistics Press.Zhang X L, Chang S Y, Ou X M, et al. 2009. A study on resources and technical potential of the development of Chinese bio-liquid fuel. Energy,Environment and Economic Research Institute of Tsinghua University.Zhang Z J, Zhu B and Xiang H Y. 2010. N2O emission and denitrification of N fertilizer on winter wheat in southwest purple soil. Journal of Agriculture Environmental Science, 29(10):2033-2040. (in Chinese)Zhang Z S and Yuan X G. 2006. Carbon balance analysis of corn fuel ethanol in life cycle. Environmental Science, 27(4): 616-619.