| Our country’s desert steppe locate in the north of our country, it is the forefront of ecological barrier. It is responsible for extremely important ecological service function, and it provides most part of livelihood of the poor.In this area, the agricultural ecology economic is developing in a vicious cycle. The most direct forms of expression are low output of herbage, and the contradiction between herbage and livestock. It is not only limits the development of the local animal husbandry, but also makes a significant contribution to the regional poverty and ecological degradation. If we can’t establish characteristics of pillar industry with sustainable economic development in this area and only rely on a small amount of food and economic compensation, it does not get rid of poverty and become better off, fundamentally and deforestation will be repeated. In order to make the agricultural resources development and utilization to achieve the best running state, promote coupling production of each subsystem in the study area, form multi-level circulation of materials and energy in compound system, enhance time sequence, spatial pattern and ecological processes of each subsystem.This study chose the peasant household ecosystem of Wanjigou Village in Yanchi County as an object. In order to make the research results accurately, we combined Participatory Rural Appraisal data, Long-term monitoring data and Laboratory test data. At first, we used the Participatory Rural Appraisal data to analyze the structure and economic flow characteristics of object household ecosystem. Second, we used energy flow analysis method to research the energy production, distribution, and conversion efficiency of system. Third, we established the material flow Compartment Model based on the laboratory test data. At last, we synthesized the above results and found out the problems of the object household ecosystem. Then, putted forward appropriate Agro-forestry-animal husbandry optimization models of the research region in order to improve the level of agricultural production and achieve good ecological, economic and social benefits.The result shows:(1)The structure and the evolution of Agroforestry-animal husbandry ecosystem in study area was affected by climate, resource characteristics and external interventions, and the most significant external interventions were converting farmland into forest and grassland project and prohibiting graze policy. Farmers’agricultural production system was stable, it completely served livestock production. But the ecological pressure of native grassland was increasing with the increasing number of the sheep and more farmers were grazing without permission. The contradiction between ecological environmental protection and farmers’livelihood was serious.(2)After analyzed the economic flow of famers’ecosystem, the results showed that the system was profitable, and the most part of economic income was derived from livestock production. The outputs of agricultural production system did not meet livestock production’s need fully, and farmers also needed to buy a lot of corn to satisfy the need of livestock. The biomass of native grassland and Caragana Korshinskii Kom was the main factor that influenced the number of the sheep. The productivity of native grassland fluctuated seasonal, and its utilization rate was low.(3)Farmers’ compound ecosystem was given priority to livestock production and supplied with agricultural production. The primary production of the system was mainly on returning organic fertilizer. Mechanical energy and fossil energy input low. The primary production energy conversion efficiency of system was low, part of biomass was wasted. The livestock production stability relied mainly on the external energy input. Because of dry weather, the fertilization conversion efficiency of land was low, and it influenced the energy conversion of secondary production system. Furthermore, it influenced the efficiency of system’s energy conversion and output.(4)Nitrogen, phosphorus input and output of farmers’ ecosystem were imbalanced. Carbon input and output were balanced. This nutrient input status did not destroy the ecological balance of farmland. Corn was the main source of nitrogen and phosphorus input to livestock production, nutrient outputs were mutton, wool and sheep droppings. The material conversion efficiency of livestock production system was higher than agricultural production system. When livestock grazing, sheep manure were input to the natural grassland as nutrients. After all, material conversion efficiency of artificial grassland was higher than other subsystems.(5)We established the material flow Compartment Model based on the laboratory test data. Setted the model parameters, then the results showed:the ratio of material flow in soil organic matter compartment was the highest, and sheep manure was the biggest contributors to soil organic matter. The efficiency of organic matter circulation expressed the corn straw was the highest, and the maize seed was higher. The core of the compound system was livestock compartment, it had a higher rate of material input and output. Although the livestock production of this region was prosperous, but the organic matter of composite feed could not transform efficiently under feed structure and feeding method at present. Under this organic production condition, the animal husbandry subsystem was stable than farm production subsystem.(6)On the basis of the above research results, we putted forward seven kinds of Agroforestry-animal husbandry optimization models. They were:Planting model with feed processing as a link, Sheep raising model with the grassland animal husbandry developing, Sheep raising model with Caragana korshinskii feed processing as a link, Complex model with Livestock products deep processing, Ecological economic model with vegetation restoration, Ecological agriculture model with using water and soil resources Efficiently, Industrialization model with cultivating alternative industry. |
PDF Full Text Request