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Emergy Analysis of Agroforestry Ecosystems in Purple Soil Area

Author: JinXueYan
Tutor: ZhuShouJun
School: Northwest University of Science and Technology
Course: Soil and Water Conservation and Desertification Combating
Keywords: Purple soil area Agroforestry systems Mode Structure Emergy analysis
CLC: S718.5
Type: Master's thesis
Year: 2010
Downloads: 66
Quote: 0
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Abstract

Purple soil area population density, per capita arable land, agroforestry ecosystem as a mode of rational development and utilization of land resources, is an effective way to solve the ecological problems of purple soil area is purple soil area is an important means of achieving sustainable development, this paper purple soil area Agroforestry system as the research object, its mode of classification and analysis of structural features, Emergy analysis method Agroforestry systems evaluation and comparative analysis, the main draw the following conclusions: (1) purple soil area forestry complex ecological system can be divided into terraces, forestry, fruit and composite systems, sloping forest belt composite system, Goudi agroforestry systems and courtyard forest and pastoral complex system. Vertical structures including double-layer structure, the three-tier structure and multi-layer structure, the level of structure, including strip intercropping peripheral planting strip Mixed block mingling and massive mosaic, etc.. (2) pears - agricultural complex, nuclear - agricultural composite, grapefruit - agricultural complex ecological system can be cast structure similar investment in the non-updated natural resources accounted for the proportion of non-renewable resources: 8.21% to 8.42%, from 11.25% to 11.80 %, from 13.19% to 14.60%, and quantitative description of the role of soil and water conservation in the purple soil area Agroforestry systems can not be underestimated. (3) three agroforestry systems were put into the labor emergy and fertilizers can value. Labor emergy possession of machine-assisted value of 51.66% to 69.69%, from 52.68% to 68.27% and from 49.18% to 72.39%; fertilizer value inorganic auxiliary value of 99.41% to 99.51%, from 98.06% to 98.87%, 98.71% to 98.84%. Manpower is the main source of power, the low level of science and technology. Large amounts of fertilizer inputs is not conducive to the long-term development of the local agroforestry ecosystem. (4) the purple soil Agroforestry system has a higher degree of economic development, which grapefruit - agricultural complex system, the net energy yield the highest price the most competitive advantage. The pear - agricultural complex system can value the highest investment rate. Three agroforestry system can value self-sufficiency rate is small, the system of production affected by the market, not strong independent development. Purple soil agroforestry system of production less pressure on the environment system, in which nuclear - agricultural complex system, the lowest environmental load rate, the most potential for development. Purple soil area of ??agroforestry systems being developed and relatively dynamic development of the system is sustainable. Grapefruit - agricultural complex system emergy sustainability indicators. (5) pear - Rape - corn, walnut - Rape - corn, grapefruit - rape - corn mode are optimal mode in the composite system, the performance of the highest in the system of production efficiency, product price competition advantage, minimal impact on production by the market alone strongest development capacity and sustainable development potential; the pear - wheat - sweet potatoes, walnut - wheat - sweet potatoes, grapefruit - wheat - sweet potato mode most of the composite system mode with development potential, in the lowest level of utilization of natural renewable environmental resources, the natural environment, the minimum load level. (6) chenjiawan watershed agricultural production in the traditional closed-end agriculture stage, the average standard of living of the farmers. Agricultural production less pressure on the ecosystem of the entire environment, system productivity, economic underdevelopment.

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