Anaragy On Cycle Of Energy And Material In The Comprehensive Ecological System Of Agroforestry Of DengKou County

The paper was conducted about Agroforestry ecosystem in Dengkou County of Inner Mongolia. The objective was five subsystems, including Farmland subsystem, Forestry subsystem, Grassland subsystem, Animal husbandry subsystem and Farmers subsystem. We used the Dengkou County statistical annual (1992~2008). Meanwhile,The paper adopted the standard of the folded energy coefficient and the methods of the field measurement, data collection, investigation and questionnaire in order to analyse the characteristics of cycle of energy and material. The results showed that:(1) In farmland subsystem the ratio of input and output is 3.17:1; In Forestry subsystems the ratio of input and output analysis, Arbores > Shrubbery > Economic forest (the ratio is 26.2:1, 7.3:1 and 1.1:1 respectively); The ratio of economic forest is lower, but it is main output of energy of forestry subsystem producers; Animal husbandry subsystems play an important role in Agroforestry ecosystem. The ratio of input and output of pig >cow >Chicken >sheep,(the ratio is 0.163:1, 0.040:1, 0.037:1and 0.036:1 respectively); The grassland subsystem received the energy of 2.9×1014J. The solar energy efficiency of conversion of grassland subsystem extremely low; Farmers subsystem is the dominant subsystem, other subsystems is provided certain energy input by it. The ratio of energy output of farmers subsystem is 0.48:1, it Shows that farmers subsystem is a typical energy consumption subsystem.(2)Total of energy input is greater than output in Agroforestry ecosystem, System is currently in a period of energy accumulation.The energy transferable potention is large with external environment.(3) Agroforestry ecosystem nutrient status of the input and output is a key which determine the output of agriculture and forestry. In DengKou county,input is greater than the output ( the nitrogen ratio of output and input is 0.74:1 phosphorus ratio is 0.30:1). The loss is too much. So we should improve the soil, increase nitrogen and phosphorus utilization, and promote the balance of the entire ecosystem and sustainable development.