Data Envelopment Analysis on Efficiency Evaluation of Irrigationfertilization Schemes for Winter Wheat in North China

Crop production is a process of multiple inputs (water and nutrients, etc.), and the relationships between the inputs and crop yield are very complex. This study used a model for data envelopment analysis (DEA) to evaluate the efficiency of irrigation-fertilization schemes for winter wheat in North China. The field experiments were conducted at the Xiaohe Irrigation Experiment Station in Central Shanxi Province, China. Sixteen irrigation-fertilization schemes, the combinations of four levels of irrigation (irrigation volume from 0 to 300 mm) and four levels of fertilizer (0, low, moderate and high), were considered in the experiments. Experimental results revealed that irrigation and fertilization have significant impact on wheat yield and water use efficiency (WUE). For schemes without fertilization, wheat yield and WUE tend to be the lowest for all the irrigation levels and vary little with irrigation volume. With a specified irrigation volume, wheat yield and WUE tend to increase with fertilizer level. At a specified fertilizer level, wheat yield tends to increase with irrigation volume, while WUE is less influenced by irrigation volume. Among the sixteen schemes, ten were evaluated to be DEA efficient or nearly DEA efficient. The results indicated that proper combination of irrigation and fertilization is necessary for efficient use of water and fertilizer. Low fertilizer level with no irrigation and low, moderate or high fertilizer levels with more irrigation volume are generally effective for winter wheat production. 40 Songhao Shang , Xiaomin Mao