Farmers’ attitude towards risk and the degree to which their decision making is risk averse will depend on a range of factors. These include: the level, security and degree of diversification of farm household income; the quality of a farmer\'s information and knowledge about output risk (as affected by weather, pests, disease, irrigation shortage etc.), agricultural input use and effectiveness, and environmental risk; the degree of trust in extension agents or other sources of advice; and the farmer’s level of education. For instance, Han and Zhao, 2009, demonstrate that there is a negative relationship between fertilizer application and farmers\' education level and knowledge of environmental impact. Babcock, 1992, shows that increasing uncertainty about XMD-17-51 nitrogen concentration and weather conditions usually increases nitrogen applications beyond the rates that would occur under certainty. Sheriff, 2005, argues that trust and a farmer\'s perceptions of agronomic advice will influence the rate of fertilizer application. If farmers perceive that the suggested rate of fertilization is too conservative, or that the recommendations of extension advisors under-estimate crop response in their fields, they may over-apply relative to the recommendation. Evidence is cited that farmers systematically over-estimate the impact of additional nitrogen relative to agronomists\' recommendations (Sherrif, 2005). Chadwick et al., 2012, note that farmers lack knowledge of the nutrient content of organic manures such as composted manure products, and animal manures are often applied to land, either as fertilizer or as a means of disposal, without adequate accounting for nutrient content applied or risks incurred. Farmers’ perceptions and knowledge of fertilizer use, its profitability and associated environmental risk are obviously key factors influencing excessive use of crop nutrients in China.