Contents Of The Soil Trace Elements And Their Availability Evaluation In Huzhou City Of Zhejiang Province

Three types of soil, paddy soil, red soil and fluvo-aquic soil including 108 soil samples in Huzhou City, Zhejiang Province, China, were sampled. The relationship among the content of the trace elements, parent material, soil pH and soil organic matter were analyzed as well as the relationship among the soils in various agricultural ecosystem, the content of trace elements in crops and their cycles and balance. The results were as follows:1.The coefficient of variation of the content of the total and available trace elements is high. The content of the total and available Cu, Zn and P was more than their mean content of Zhejiang Province but that of the total and available Mn and Mo was less.2. There were large parts of the paddy soil, red soil and aqusol in Huzhou City lack of the Mo and P, especially lack of the P seriously. Some soils were lack of the Mn. Except the less parts of the aqusol and red soils, the content of the available Zn was much as well as that of available Fe and Cu was much more.3.The content of the trace elements in Huzhou City was affected by the types of the soil and the parent material but affected by the types of the soil absolutely. The content of the trace elements come from various types of the soil but from the same parent material was much different.4. Soil pH, the content of the soil organic matter had many effects of the content of the soil available trace elements. The content of the available trace elements increased with that of the soil organic matter increasing, but decreased with much more that of organic matter. The content of the available trace elements correlated with the soil pH significantly in some pH width.5. Human's activity had also many effects on the content of the soil trace elements. In paddy soil and vegetable fields there were more available trace elements than those in the forest-grass ecosystem.6. In the four agricultural ecosystem of Huzhou City the forest-grass ecosystem was the most stable and the Mulberry ecosystem easiest to suffer the lack of the trace elements. In rice field ecosystem there were some huge pools of the trace elements except the P. Vegetable field ecosystem suffered the lack of the trace elements more easily than rice field.