农田生态系统中钾循环研究进展

论述了农田生态系统中K的收入和支出,以及K的循环再利用等方面的研究进展，并针对当前K循环存在的问题提出了调控方法.从全国来看，我国施用K的数量比作物收获时从土壤中带走的K的数量少得多，K一直处于负平衡状况.我国土壤K肥力不断下降、钾肥有效地区不断扩大，虽然钾肥用量在逐年增长，但补充的K尚不能维持K的收支平衡.为了维持与提高土壤K肥力，使作物高产稳产，在今后农业生产中应充分注意土壤K的平衡，优化农田生态模式，注重水肥调控，坚持有机肥与无机肥配施的原则，促进K养分循环，保持农田K平衡，提高土壤K肥力.

Research advance in potassium cycling in agroecosystems

This paper reviewed the research advance in the budget of potassium in agroecosystems and the reuse of recycled potassium. Some strategies were brought forward to solve the problems in potassium cycling. In China, the amount of applied fertilizer potassium was far less than that of the potassium carried off by crops from soil, and thus, potassium was of negative balance all along. Soil potassium fertility was decreased continually, and the areas available to potassium application was extending. Though the application rate of potassium was increasing, the potassium balance was still of negative, To maintain and improve soil potassium fertility and to obtain high and stable crop yield, enough attention should be paid on soil potassium balance, structural optimization of agroecosysterns, regulation of water and fertilizer, and combined application of organic and chemical fertilizers.