农田生态系统生产力演变及驱动力

 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。

Changes of Ecosystem Productivity Responding to Driving Forces in Semiarid Region

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 productivityand their changing conditions were discussed. It was found that fertility was the major limiting factor on the condition of lowlevel productivity, and water has gradually become the primary limiting factor to continuous yield increase along withchemical fertilizer application being extensively applied and productivity being increased. Chemical fertilizer and plastic filmare main driving forces for increase and stability of productivity.