关键词: 沙地, 农业生态系统, 可持续发展, 延津

Abstract: The Yanjin sandy land of north Henan Province,located at the Huang-Huai-Hai plain,is a piece of wind-sandification land on the ancient Yellow River Course in the semi-humid zone with the seasonal desert ecosystem on the dry land.It is very easy to be desertified under disturbance of human activities and the fluctuation of drought climate.Since 1988,the wind-sandification land has been developed and ameliorated comprehensively.At first,it was set up the water conservancy system with the supplement irrigation by groundwater and drainage by ditch to provide the efficient moisture for the sandy land.Then the protection system with shelter-belt and woodlands of sand dunes was constructed to control the local wind erosion and sandification.It was also carried out the fertilizing system of sand lands with organic and chemical fertilizers in the development of agriculture,forestry and livestock to increase the organism and nutrient elements of sandy soil.The 110hm^-2 garden area includes the cash forest subsystem of orchards,the cropping subsystem of farmlands and the raising subsystem of grass livestock with the ratio of 3:4:3(orchards:farmland:woodland).A successful experience ameliorating and developing waste sandy land has been gained through practice of sandy land on the ancient Yellow River course.Although the product system of fruit-forestry of sandy land,the distinguishing product system of cropping agriculture on sand land and animal husbandry system of grass livestock are formed and developed progressively by construction for 12 years,it is necessary to put the invest and techniques into this middle-yield farmland.We are still making efforts on the agroecosystem to achieve the sustainable development of the environment,resources and production on sandy land through agriculture industrialization and adjusting the structure of cropping according to market.

Key words: sandy land, agriculture ecosystem, sustainable development, Yanjin County