The Study Of Sustained Management Development Of The Agroforestry System Of The Northeast Ulan Buh Desert

The region of North-east Ulan Buh Desert is at the east edge of West Inner Mongolia. From 50 years ago till now, there have been consistent efforts from the Dengkou county government and local communities on forestation and large areas of artificial protection forest have been planted in areas at the edge of the northeast of the Ulan Buh Desert, thus stopping the movement of desert and protection of farmland. Desert protection forestry belts and farmlands are interlinked, constituting a large number of agroforestry systems of various sizes and relatively self-contained functions, and forming landscapes of artificial oasis in northeast Ulan Buh Desert. As a unique geographical landscape supporting the social and economic sustainable development of arid areas, the landscape of artificial oasis has become the most important areas of research on sustainable development in northeast Ulan Buh Desert.The agroforestry systems are established on the basis of the ecological characteristics of the religion northeast of Ulan Buh Desert. What are the scientific and rational ways to make best use of the local natural resources? How big are the differences of benefits for different models of agroforestry arrangements? What are the major problems of the existing farmland protection agroforestry systems? What operational measures are to take to maximize economic, social and ecological benefits in a sustainable way? These are the urgent problems needing to resolve in scientific ways.Focusing on these urgent issues, from 2006 to 2009 the author take as the research object the agroforestry systems, which is the important ecological unit of Ulan Buh Desert northeast of artificial oasis. Through data research, expert advice, household surveys, site visits and testing, among other means, the author has studied and analyzed the agroforestry systems both qualitatively and quantitatively, the relation between rational utilization of water resources and sustainable development, focusing on the relation between land used situation and farmers living,the micro-climate benefits of oasis and its impact on crop yields, energy flows and logistics, as well as evaluation of comprehensive benefits. The main conclusions are as follows:On the basis of the analysis of the balance of water resources in northeast region of the Ulan Buh Desert, the prediction and analysis of the balances of water resources of and carrying capacity indicators of three scenarios of high, medium and low inflows of water from the Yellow River in 2010 are made. We can see that inflow of water from the Yellow River the Yellow River water is the 3.4×108 m3/a, when the water supply and demand are in balance. From the groundwater development, however, there is some potential for the development of groundwater irrigation, which lays a solid foundation for continuing operations of the agroforestry systems in the region. In the 18 years from 1991 to 2008, the changes of land-uses for agricultural and forestry uses are great (2.47-12.7 ha), which has made a great impact on the living conditions of farmers. Per capita income and per capita spending have been continuing to increase and there are increasingly surpluses of income (the average per capita income of farmers in 2008 is 2963 yuan, which is 18.87 times that in 1993) ; farmers'living space are larger and larger and their living environment has been improving. The ecological functions of the forest improve the living environment of farmers.The effects of the agroforestrial arrangement of one line of elm +2 lines of populus +1 line of elm plus maize composite system is the most obvious. Compared with the pure agricultural land, the agroforestry systems can regulate micro-climate, making the system more conducive to complex crop growth and development. The soil physical properties of a line of elm +2 lines of poplars +1 line of elm plus maize and a line of elm +2 lines of Salix +1 line of elm plus tomato complex systems are better than those of other composite systems. Soil chemical properties of 3 lines shaft Yang +2 lines poplars +3 lines of shaft Yang - 8 rows of corn and poplar - Pythium complex system are better than those of other systems, with substantial increase of contents of organic matters and nutrients.For the agroforestry system of Dengkou County, as energy input is bigger than output, most energy accumulates in the system. The agroforestry system greatly depends on the outside environment of the system, with high potentials of exchanges of energy between the inside and outside of the system. The nitrogen and phosphorus inputs of the agroforestry systems of Dengkou County are greater than the outputs, which greatly affects the nitrogen and phosphorus input output ratios and the effective use of land. Taking the entire agriforestry systems into account, the nitrogen input output ratios is 0.74, which is big than 0.30 input output ratios of phosphorus.The net benefits of agroforestry systems were significantly higher than those of pure agricultural land and pure woodland systems. Among them, the greatest economic benefit come from the composite system of one line of elm +2 lines of Populus +1 line of elm plus maize, followed by the composite system of one line of elm +2 lines of Salix +1 line of elm plus tomatoes, the composite system of 2-lines of shaft Young plus sunflower and the composite system of 3 lines of shaft Yang +2 lines of Populus +3 lines of shaft Young plus maize. In these three complex systems, the output values and net benefits are higher than those in the composite system of a line of elm +2 lines of Salix +1 lines Elm plus tomato. The agroforestry systems and the pure forest systems are significantly better than pure agricultural land systems in terms of overall efficiency. The composite systems are better than pure woodland systems (Populus woodlots) in terms of overall efficiency for composite systems of one line of elm +2 lines of Populus +1 line of Elm plus corn, one line of elm +2 lines of Salix +1 line of elm plus tomatoes and 2 lines of shaft Yang plus sunflower, which are 3.71 times, 2.95 times and 2.77 times those of purely agricultural land respectively.