【作者】 王树涛；

【导师】 许皞； 李博文；

【作者基本信息】 河北农业大学 ， 土壤学， 2008， 博士

【摘要】 粮食是国家发展和社会稳定的基础,解决粮食问题也就成了社会和经济发展的基本目标。但是,随着人口增长与资源衰竭矛盾的日益凸现,人类粮食需求量的增加与耕地资源量缩减的矛盾迅速激化,耕地这一维持作物生长、保证粮食供应的基础资源正在承受前所未有的压力。生产力是耕地的基本特征,其稳定性反映了耕地利用系统的结构、功能与发展趋势,目前已成为解决粮食安全问题的热点。因此,如何保证耕地生产力的持续稳定提高成为缓解人地矛盾的关键。但是,目前学术界还未在耕地生产力稳定性研究方面达成一致结论。鉴于此,本文在前人研究的基础上,从耕地生产力趋势性和波动性两个角度,对耕地生产力稳定性评价的理论、方法进行了探讨,并以河北省耕地系统为例,在宏观区域尺度上对耕地生产力稳定性及其影响机理进行实证研究。主要结果如下:1.耕地生产力稳定性理论和方法论根据耕地生态系统功能特性和耕地生产力变化特征,提出耕地生产力稳定性的内涵应同时包括粮食产量长期趋势的持续稳定增长和产量波动的最小化。运用经验模态分解法把粮食产量分解为粮食趋势量和粮食波动量,通过建立稳定性模型对两者进行有效拟合,构建了生产力稳定性评价方法体系。2.河北省耕地生产力稳定性实证评价(1)1978～2005年河北省粮食总产量稳定性呈从增加到逐步减低的态势,并存在两个较大的变化阶段。2003～2005年耕地生产力稳定性最差,生产力处于衰退阶段,而1978～2001年稳定性指数变化中,有16个年份稳定性处于较差级别,4个年份为较好级别,4个年份为最稳定级别。(2)河北省粮食总产稳定性结构态势中,从作物种类上,小麦和玉米产量的稳定性对总产量稳定性影响最大:从空间范围上,太行山山前平原区和辽吉西蒙东南冀北山地的稳定性对河北省总体稳定性具有重要影响。(3)纵观河北全省,有27个县区耕地生产力稳定性处于最差级别,稳定性指数都为负值;17个县区耕地生产力稳定性属于较差等级;64个县区的耕地生产力稳定性较高,属于较稳定级别;35个县的生产力稳定性级别最好。河北省耕地生产力稳定性最差的两个等级的面积占河北省总面积的48%。3.河北省耕地生产力稳定性因素影响定量化研究(1)1978～2005年河北省粮食总产趋势量增长了1.72%,粮食作物播种面积趋势量增加对粮食总产趋势量增长的贡献率为51.99%,有效灌溉面积对粮食总产趋势量增长的贡献率为38.68%,科技进步对粮食总产趋势量增长的贡献率为12.73%。农林牧渔业劳动力和支持农业生产和事业支出两个因素的变化抑制了粮食总产趋势量的增长。(2)在影响河北省粮食总产量波动的因素中,按对粮食总产波动的贡献率大小,依次为成灾面积、有效灌溉面积、粮食作物播种面积、支援农业生产及农业事业费用、降水量和化肥施用量6个主控因素,其影响度的总和达到了78.8%。通过各影响因素的影响度综合分析可知,自然资源、固定资产和可变要素投入的波动性变化是河北省耕地生产力波动形成的主要原因。更多还原

【Abstract】 Grain production is the basis of social stability and development, therefore, solve the food problem will become a basic objective for social and economic development. However, with increasing of population and resource exhaustion, the confliction between human demands for food strengthen and cultivated land reducing is gradually intensified. Productivity is the basic characteristic of farmland. The stability of productivity implies the structure, function and developmental directions, which has become a hot issue to solve the current food security. Therefore, how to ensure the continuous stability of farmland productivity were the key to ease confliction between people and land use. Nevertheless, there are no integrated theories, means and methods on the stability of farmland productivity at present. Based on previous research, the paper focus on Hebei province case and discuses the theory and methods on assess stability of farmland productivity in view of trends and fluctuations. The main findings as follows:1. Stability theory and methodology of farmland productivityBased on the ecosystem function of farmland and characteristics of food productivity, the paper pointed out connotation of food productivity stability includes long-term sustained and stable growth of output in food production and minimize fluctuations. By Empirical mode decomposition (HMD) method, the food productivity was divided into trends and fluctuations. And then, stability models fit the two factors effectively to build evaluation system of productive stability.2. Stability evaluation of farmland productivity in Hebei province(1) From 1978 to 2005, the stability of grain output in Hebei Province was fluctuating from increase to decrease. There are two significant stages. The stability of crop productivity was worst from 2003 to 2005, recession in a stage of productivity. As to stability index from 1978 to 2001, there were 16 years in the unstable grade, 4 years in the stable grade and 4 years in the most stable grade.(2) During the formation of crop productivity stability in Hebei Province, wheat and corn output plays the most important role on total production. Piedmont of the Taihang Mountains and northern Hebei province has the significant impact on overall stability. (3) In Hebei province, stability of crop productivity in twenty seven counties is worst and the corresponding stability index is negative; stability of the crop productivity in one seventeen counties belongs to the unstable grade; sixty four counties have poor food productivity, belonging to the stable grade; stability of crop productivity in thirty five counties is best. The cultivated land areas which belong to the unstable grade accounted for 48% of the whole province.3. Factors of productive stability in Hebei Province(1) From 1978 to 2005, grain output increases 1.72% in Hebei province. There are several factors could influence stability of crop productivity and the contribution rate is various. The cultivated area increasing has a positive effect on the crop output and accounts for 51.99%; effective irrigation area accounts for 38.68%; scientific and technological progress accounts for 12.73%. However, Agricultural input and business spending suppress the output increasing.(2) The factors which influence output fluctuation in Hebei province were classified into hazard area、effective irrigation, planting area, supporting spending, rainfall and fertilizer application according to contribution rate to crop productivity fluctuation. They could account for 78.82% compare with other factors. Analysis by influence degree, we conclude that fluctuation of natural resources、permanent assets and various constituents was the main contributor for crop productivity fluctuation in Hebei province.更多还原