Eco-efficiency of oasis seed maize production in an arid region, Northwest China.

Improving eco-efficiency in arid areas is the crucial to resolve the dual constraints of scarce water resources and the fragile carrying capacity of the ecological environment on agricultural production. This study investigated the eco-efficiency of seed maize production in Zhangye City, the largest seed maize producer in the arid northwestern region of China. The environmental impacts were assessed through a life cycle assessment and incorporated into a data envelopment analysis model, together with economic factors to evaluate ecological efficiency. A Tobit regression model was applied to identify the key elements affecting eco-efficiency and determine suggestions for further improvements. The results showed that the environmental acidification index of Zhangye was 1.2079–1.3978 times larger than the world per capita level, with the primary cause being the application of nitrogen fertilizer. Water consumption was lower than the world average level. The comprehensive environmental index was lower than the 2000 world per capita level but higher than that of other Chinese regions. A production eco-efficiency evaluation showed that 14.68% of households achieved relatively efficient production. Water was the most influential element. Each additional 100 units of water reduce eco-efficiency by 0.34%. A comparative study of small, medium and large farms was carried out to examine the effect of farm size. Small farms were the most eco-efficient, followed by medium-sized farms, with large farms having the lowest eco-efficiency. The results highlighted that certain targeted policy interventions may be inefficient, including interventions focusing on expansion of the production scale, and that restrictions on fertilizer use and improving water-saving facilities can improve eco-efficiency performance. Image 1 • Environmental impacts of NW China oasis are lower than 2000 world values per capita • 14.68% of oasis households achieved relatively eco-efficient production in NW China • Fertilizer and water are the main factors affecting eco-efficiency in NW China • Eco-efficiency is highest for small farms followed by medium-sized then large farms • Controlling fertilizer, water & farm size helps improve eco-efficiency in NW China [ABSTRACT FROM AUTHOR]