【作者】 李新旺；

【导师】 许皞；

【作者基本信息】 河北农业大学 ， 土壤学， 2011， 博士

【摘要】 粮食安全对于人类——无论古今中外始终都是不可或缺的最基本的生存条件,也是社会稳定和国家发展的基础。从粮食安全层级关系和支撑关系来看,中小尺度耕地生产力稳定地发展是粮食安全最基础的支柱,没有中小尺度耕地生产力的稳定发展,粮食安全就失去了基础,人民生存就缺少了基础保障,社会稳定和经济发展也就成了无本之木。随着中国加入WTO以及国内工业化、城镇化的快速发展和人口的刚性增加,“粮食安全”问题的尖锐性和紧迫性日益凸显。在新的历史条件和发展环境下,我们过去一直讨论的耕地粮食生产问题的内涵已经不能简单地用增长或波动二个字眼来概括。在此形势下,掌握耕地生产力的发展规律和主导因素,预知耕地生产力发展的趋势,就成为农业研究中的一个热点和重要课题。基于此,作者选择粮食安全问题众多研究之一隅,从耕地生产力的新特征——“稳定性”研究入手,以黑龙港流域粮食主产区雄县为例,在粮食安全问题的最根本层次——中小尺度上对耕地生产力稳定性的评价理论和方法进行了实证探索和研究。主要发现和研究结论如下:(1)根据耕地生态系统功能特性,耕地生产力形成机理和发展特征,提出了中小尺度耕地生产力稳定性包括趋势性和波动性两个组分,具有县域尺度和田块尺度(包括农用地块和实验地块两种类型)两个层次的稳定性内涵。通过改进前人区域耕地生产力稳定性表达模型,建立了中小尺度耕地生产力稳定性表达模型,并以EMD、剩余法、TFP和RS等方法为依托,构建了中小尺度耕地生产力稳定性评价方法体系。(2)明确了1949~2008年间雄县粮食总产由1个R趋势分量和4个IMF波动分量组成。其中,趋势分量R以1978、1998为界呈缓慢发展→快速增长→徘徊不前三个阶段特征发展,且其方差贡献率高达89.61%是该县粮食总产的最大贡献组成。粮食产量波动分量IMF具有明显的多时间尺度特征,分为3、7、11和30年四个尺度的周期,其对粮食总产量的方差贡献率次序为IMF2>IMF4>IMF1>IMF3,其中IMF2最大为4.43%,是这一时期粮食产量波动的重要特征。(3)揭示出建国以来,雄县耕地生产力稳定性的发展变化以1965、1986、1991和2001年为界线经历了低位徘徊→持续发展→逐渐衰退→快速提升→缓慢恢复五个阶段的发展规律。探明了粮食单产60年间对雄县粮食总产稳定性影响度为72.71%,粮食播种面积影响度为26.10%,但后者各阶段多为负值,是降低稳定性的因素;阐明了雄县耕地生产力的稳定性呈现强弱镶嵌分布的整体空间格局,其中朱各庄镇最强,雄州镇最弱。在作物种类结构方面,各作物的稳定性程度次序为,玉米>小麦>杂粮。(4)探明了有效灌溉面积、化肥施用量和科技进步贡献率是1978~2008年间雄县耕地生产力稳定性发展变化的主导因素。其中,趋势性主导因素分别为,化肥施用量、有效灌溉面积、科技进步贡献率、乡村劳动力、农作物受灾面积和农药使用量,其影响度依次为,57.18%、31.52%、16.43%、4.10%、-5.13%和-4.10%;波动性主导因素分别为,农业机械总动力、农药施用量、年积温、化肥施用量和年降水量,其影响度依次为,30.77%、23.08%、23.08%、15.38%和7.69%。(5)探明了长期不同施肥下,田块尺度耕地(实验地块)生产力稳定性差异较大的发展特征。其中,NPK三元素全施处理的稳定性较高, NPK偏施处理的稳定性较差,尤其以No和Po处理最差。在过去13年当中,气象因子的综合作用致使实验各处理小麦产量稳定性下降了4%~22%,致使实验各处理(除CK和No)玉米产量稳定性下降了2%~20%。更多还原

【Abstract】 Food security is not only the indispensable condition for human survival, but also the foundation of social stability and national development in all the times and over the world. According to the relationship of food safety grade and support, the steady development of cultivated land productivity is a most fundamental pillar in the mid-and micro-scale cultivated systems. Without its steady development, the basic guarantee for food safety and people survival would disappear; the social stability and economic development would be non-existent. In particular, with the China’s accession to the WTO and the rapid development of domestic industrialization and urbanization and the large increase of population, the problem of food security is gradually acute and urgent day by day. Furthermore, the meanings of cultivated land production which we always discussed in the past time hadn’t been recapitulated by growth or volatility in the new historical condition and developmental environment. Hence, the issue of developmental rule and dominating factors accompanied with predicting development trend of cultivated land productivity became a hot topic in agricultural research nowadays. Based on this, by using the cultivated land of Xiong County in Hebei Province as an example, the research was constructed with beginning of the new feature of land productivity—“stability”to explore and study the evaluation theories and methods for stability of cultivated land productivity in the mid-and micro-scale cultivated systems. The main findings and conclusions were as follows:(1)According to the functional properties of cultivated land ecosystem and the formation mechanism and development characteristic of farmland productivity, the result showed that the stability of mid-and micro-scale cultivated land productivity included two components—trends and volatility. The meanings of stability could perfectly meet the two kinds of land in county scale and field scale (including the agricultural land and the experimental land). Through improvements to the earlier expression model for the stability of regional land productivity, the new expression model were constructed for mid-and micro scale farmland production. Then, the evaluation system for stability of cultivated land productivity was built on using the methods of EMD, remaining method, TFP, RS and so on.(2)It was found that a R trend component and four IMF fluctuation components of grain production in Xiong County during 1949 ~ 2008. Particularly, the course of R trend components was divided by the year of 1978 and 1998 into three phases, i.e. slow development, rapid growth and linger. And its variance contribution reached up to 89.61%, which was the most important contribution for grain production in Xiong County during 1949 ~ 2008. Additionally, the multi-time scale characters of IMF fluctuant components were presented in the 3,7,11 and 30 years time-scales. The variance contribution for total grain output were in the order of IMF2>IMF4>IMF1>IMF3. The maximal variance contribution was 4.43% for IMF2, which was a significantly feature of grain output fluctuant in this period.(3)The development of stability of farmland productivity has gone through the low wandering stage for the 1965 ago, sustainable development stage for the periods of 1965 -1986, gradual fall stage for the periods of 1986 -1991, fast growth stage for the periods of 1991 -2001 and slow recovery stage for the periods of 2001 to now in Xiong County since the founding of China People’s Republic. The effect of grain yield on influential degree of grain output and grain sowing area is 72.71% and 26.10% among the 60 years in Xiong County, respectively. However, the latter reduced the stability of farmland productivity as its negative values during the most development stages. The strong and weak mosaic pattern for stability of farmland productivity was showed in the space structure of Xiong County. The Zhugezhuang town had the strongest stability, while the weakest stability was recorded in Xiongzhou town. Moreover, the stability degree for kinds of crop was in the order of corn >wheat>minor cereals.(4)The result also showed that the steady development of farmland productivity was mainly determined by the effective irrigation areas, consumption of fertilizers and technological progress during 1978~2008 in Xiong County. The leading factors were consumption of fertilizers, effective irrigation areas, technological progress, rural labor, crop disaster area and pesticide consumption which covered the influential degree by 57.18%, 31.52%, 16.43%, 4.10%, -5.13% and -4.10%, respectively for trends of land productivity, while the dominant factors were total power of agricultural machinery, pesticides consumption, annual cumulative temperature, fertilizers consumption and annual precipitation which covered the influential degree by 30.77%, 23.08%, 23.08%, 15.38% and 7.69%, respectively for volatility of land productivity.(5)The stability of cultivated land productivity was marked in different development characteristic under the long-term different fertilization in the field-scale land (experimental land). The higher stability and lower stability was observed for all NPK fertilization treatment and imbalanced NPK fertilization treatment, respectively. In particular, the worst stability was showed in N0 and P0 treatment. In the past 13 years, the decrease in stability of wheat yield by 4%~22% accompanied with decrease in stability of maize yield by 2%~ 20% (exception of CK and N0) was observed for the experimental lands because of the integrated function of meteorological factors.更多还原