Life cycle assessment of wheat-maize rotation system emphasizing high crop yield and high resource use efficiency in Quzhou County

Life cycle assessment (LCA) method was used to examine the environmental impact of wheat-maize rotation system emphasizing double high in Quzhou County. The LCA considered the entire system, from raw material extraction to grain production, in arable farming to produce 1 ton each of winter wheat and summer maize. Results indicated that double high agriculture could improve the yield of winter wheat and summer maize by 6.84% and 9.80% respectively, while decreasing the demand for non-renewable energy resources by 13.18% for winter wheat, and 17.45% for summer maize. In the double high production system, N and P fertilizer application was decreased by 5.23% and 7.79% for winter wheat production, and 2.37% and 56.54% for summer maize production. Less use of fertilizers in the winter wheat-summer maize production system decreased global warming, acidification, and aquatic eutrophication potentials. In the double high system, farmers decreased pesticide use by 10.64% for winter wheat and 19.57% for summer maize, thus reducing their potential evaporation, leaching, and surface run-off to environment. In addition, the double high agriculture decreased the heavy metal release to soil as a result of lower use of P fertilizers. In conclusion, the double high agriculture could decrease global warming, acidification, aquatic eutrophication, human toxicity, aquatic eco-toxicity, and soil eco-toxicity potentials as well as life cycle environmental impact index of winter wheat-summer maize production system. The practice in Quzhou County showed that double high system of winter wheat-summer maize production could increase food production while protecting environmental quality and conserving natural resources, and is thus applicable to North China Plain.