【作者】 卞莹莹；

【导师】 宋乃平；

【作者基本信息】 宁夏大学 ， 草学， 2015， 博士

【摘要】 荒漠草原区位于我国北部生态屏障的最前沿,担负着极为重要的生态服务功能；承担一部分贫困人口的生计。该区农业生态经济发展长期处于旱、薄、粗、单、低、穷的恶性循环之中。最直接的表现是荒漠化和自然灾害严重,草地牧草产量低,草畜矛盾突出,这不仅限制了当地畜牧业发展,同时也加剧了区域贫困和生态恶化。在该区域如果不能建立起特色支柱产业使经济可持续发展,仅靠少量的粮食和经济补偿并不能从根本上解决农民的脱贫致富问题,毁林毁草开荒耕翻种植还会反复。为了使农业资源的开发利用达到最佳运行状态,促进研究区生态系统中各子系统之间的耦合生产,形成复合经营系统内物质的多级循环和能量的扩大流动,增强各子系统之间的时序性、空间格局和生态过程。本文选择我国典型荒漠草原区宁夏盐池县为研究区域,皖记沟行政村农户为研究对象,将参与式农村评估法取得的问卷调查数据和长期监测数据、实验实测数据相结合,首先,利用问卷数据分析现有农户生态系统的结构、经济流特征；接着,采用能流分析方法研究系统能量的生产、分配和转化效率；然后,利用实验实测数据分析农户生态系统的养分循环、转化与利用,并在此基础上建立农户生态系统物质流动分室模型；最后,综合以上结果找出目前农户复合生态系统运行中存在的问题,进而提出适宜研究区的农业资源复合经营发展优化模式,为大幅度提高整个农业的生产水平,取得良好的生态、经济和社会效益提供参考。本文取得的主要研究结果如下：(1)研究区现有农林牧复合系统结构和演化主要受到气候、资源特征和外部干预的影响,其中外部干预中最主要的就是退耕还林还草和禁牧政策的实施。在灌溉条件下,农户农业生产系统相对稳定,且完全服务于畜牧业,但羊只数量的增加加大了生态与生计的矛盾。(2)通过对农户生态系统的经济流分析得出,目前系统处于盈利状态,农户的经济收益主要来源于畜产品,自产作物籽粒和秸秆不能满足畜牧业的饲草料要求,农户仍需购买大量的玉米。假设将羊只数量(Y)作为自变量,引入自产玉米量(X1)、自产秸秆量(X2)、天然草地生物量(X3)、购买玉米量(X4)、柠条林地可食生物量(X5)五个因素为因变量,建立多元线性回归方程,采用逐步线性回归分析法得出结论天然林草地生物量和柠条林地可食生物量是影响农户羊只养殖数量的主要因素,天然林草地生产力随季节变化明显,利用率较低。(3)农户农林牧复合生态系统是以畜牧业生产为主,种植业为辅的综合经营性农业生态系统。系统的初级生产以有机肥还田为主,机械能和化石能投入低,初级生产系统的能量转化效率不高,部分生物能流失和浪费。畜牧业生态系统的稳定主要依靠外部能量的输入。受干旱气候影响,农作物和林草地的水肥转化效率低,影响了次级生产系统的能量转化,从而影响整个典型农户生态系统的能量转化率和产出率。(4)农户农田生态系统除碳元素外,氮、磷元素的输入输出不平衡,但目前这种氮、磷元素的投入状况不会破坏农田生态系统的养分平衡。玉米是畜牧业生产系统氮、磷元素的主要输入源,营养输出形式为羊肉、羊毛、羊粪,畜牧业生产系统的物质转化效率高于农田生态系统；天然林草地的物质输入以牲畜自由放牧时产生的粪便和植物枯落物为主；总的来说,人工草地的物质转化效率高于天然草地、柠条林地和农耕地。(5)建立农户农林牧复合系统的物流分室模型,以农户调查和田块监测数据为依据,设定模型参数后得到以下结果：土壤有机质分室的物质流通率为各分室最高,牲畜放牧时产生的粪便对土壤有机质的贡献率最大,有机质流通效率表现为秸秆>籽粒>柠条>根茬>牧草。畜牧分室复合系统的核心,有着较高的输入及输出率,说明研究区畜牧养殖较为发达,但在目前这种饲料结构和饲养方式下饲草料有机质不能有效转化。在目前这种有机生产模式下,畜牧业子系统比种植业子系统稳定。(6)在以上研究结果的基础上,本文提出了以饲料加工为纽带的种植型模式、以草地畜牧业为核心的养羊模式、以柠条饲料加工为纽带的养羊模式、以增值为特征的农畜产品深加工复合模式、生态经济型林草植被恢复模式、高效合理利用水土资源生态农业模式和替代产业培育及产业化经营模式这七种农林牧复合优化模式。更多还原

【Abstract】 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.更多还原