作者从气候效应的角度,对分布于美国加利福尼亚州北方的六种土壤进行了研究,研究土壤利用过程中土壤有效养分随季节的被动变化。两年中逐月测定土壤的有效N、S、P、Ca、Mg和K。结果表明,土壤无机N两年中各土壤的季节变化均不大,土壤N的含量水平和变化 From the perspective of climate effect, the authors studied six soils distributed in the northern California of the United States to study the passive changes of soil available nutrients with seasons in the process of soil utilization. Soil available N, S, P, Ca, Mg and K were measured monthly by two years. The results showed that the seasonal changes of soil inorganic N in two years were not large, the soil N content levels and changes