Yield Performance and Resource Efficiency of Double-Cropping Maize in the Yellow, Huai and Hai River Valleys Region

The winter wheat-summer maize relay system is the main cropping system in the Yellow, Huai and Hai River Valleys region. In recent years, because of climate changing, the winter freezing and drought have occurred frequently. To take full advantageof highphotosynthetic and high resourceutilization efficiencyof C₄crop, we explored the double-cropping maize system. The experiment was conducted in Xinxiang, Henan province in 2009 and 2010 growing seasons, comparing the grainyieldperformance andresource efficiency between double croppingmaize andthe winter wheat-summer maize cropping system. The results showed that the annual yield of double cropping maize was slightly high, the average yield of two years increased by 2.3%;annual light energy and temperature production efficiency increased by 26.1% and 6.5% respectively; the economic benefit increased by 1 628 Yuan ha^-1 and there was a farmland fallow of 140 days. It illuminated that the double-croppingmaize systems with facilitating soil fallow and avoiding winter freezing injure and drought were of high light and temperature efficiency, good economic efficiency, simplified planting patterns, and ecological security model, which will supplement winter wheat-summer maize model, and also remedy winter wheat loss in the Yellow, Huai and Hai River Valleys regions.