关键词: 双季青贮玉米, 物质与能量生产效率, 资源利用效率

Abstract:

The conventional cropping systems were winter wheat-summer maize and single spring maize in the two harvest regions in the middle of China. However, with the increasing of market requirement for animal products, the cropping systems have been changed and forage production enhanced recently. In order to explore the new cropping system which was benefit for the livestock development using silage as food of saving grain，high matter production and resources use efficiency, the field experiments were conducted in the two harvest temperature limited regions of Beijing in 2004 and 2005. The ecologic elements of radiation, temperature and rainfall were detected by U.S.A BR-CR23 Automatic Energy Balance System and dry matter production was detected. Also matter production and resources use efficiency were compared between double-cropping silage maize (Zea mays L.) systems and conventional cropping systems, which were winter wheat -summer maize and single spring maize systems. The results showed that anniversary production efficiency of dry matter, energy production, radiation production efficiency, light energy production efficiency, temperature production efficiency and water production efficiency were 10.3%, 11.9%, 12.5%, 60.7%, 22.5%, and 36.3% more in double-cropping mulching film silage maize-maize system than in conventional winter wheat-summer maize system, respectively, so was it compared with spring maize. These results indicate that double cropping silage maize system performs higher yield and high production efficiency in natural resources use because of high photosynthetic traits of double-C₄ plant, and longer growth and development period by the optimization technological measures of the double-cropping-incorporate cultivation: mulching cultivation in the first reason, varieties configuration in two reasons and the growing time distribution in whole year, and so on. Therefore, the cropping system can raise natural resources use efficiency and fully exert the common effect of light, temperature and water in a whole growth and development period. The novel system opens a new way for the cropping diversity and effective production in this region. The management is simple and the cost is low for silage maize planting, so it has better economic benefit and a broad applied prospect.

Key words: Double-cropping silage maize system, Matter and energy production efficiency, Natural resource use efficiency