农田生态系统生产力演变及驱动力.pdfVIP

中国农业科学 2004,37（4）：510-515 Scientia Agricultura Sinica 农田生态系统生产力演变及驱动力 1 1，2 1 钟良平 ，邵明安 ，李玉山 1 （中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室/西北农林科技大学，杨凌 712100； 2中国科学院地理科学与资源研究所，北京 100101） 摘要：依据农田生态系统水、肥、产量关系长期田间定位试验资料，系统分析了旱作农业区农田生态系统生产 力及其限制因子的演变过程，探讨了对限制该区生产力提高的水、肥因子的主次及转化问题。结果表明，生产力水 平较低时，肥是首要限制因子;随着化肥投入的增加和生产力水平的提高,水分因子逐渐转化成为首要限制因子。化 肥和地膜覆盖栽培是该区生产力跃升和稳定的主要驱动力。 关键词：农田生态系统；生产力演变；限制因子；驱动力 Changes of Ecosystem Productivity Responding to Driving Forces in Semiarid Region 1 1,2 1 ZHONG Liang-ping , SHAO Ming-an , LI Yu-shan ( 1State Key Lab oratory of Soil Erosion an d Dry lan d Farming on the Loess Plateau, Institute of Soil a nd Water Conserva tion, Ch inese Academy of Sciences, Ministry of Water Resources/ Northwest Sci-Tech University of Agriculture and Forestry, Yang ling 712 100; 2 Institute of Geograp hical Sciences a nd Nature Resources Research, Chinese Academy of S ciences, B eij ing 10 0101) Abstract: Based on a long-term experiment about the relationships among water, fertility and yield in dryland ecosystem, the change of productivity and its limiting factors were analyzed, and the order of water and fertility importance to productivity and their changing conditions were discussed. It was found that fertility was the maj or limiting factor on the condition of low level product ivity, and water has gradu ally become the pr imary limit ing factor to cont inuous yield increase along with chemical fertilizer application being extensively applied and productivity being increased. Chemical fertilizer and plastic film are main driving forces for increase and stability of pr oductivity. Key words: Farmland ecosyst