洞庭熟，天下足：湖南省洞庭湖地区土壤肥力评价

Soil fertility evaluation in the Lake Dongting region,Hunan Province,China

以《湖南省洞庭湖区生态地球化学调查》项目为依托,在洞庭湖区多目标区域地球化学调查的基础上,对N、P、K、B、Mo、Mn、Se等元素全量或有效态含量进行了分级评价,运用层次分析法开展了洞庭湖地区土壤肥力的综合评价。结果表明:湖南洞庭湖地区土壤全氮、全钾含量适中或丰富的区域约占全区的96.5%和99%,全磷含量略低;按照区域地球化学统计原则回归得到了本区的有效氮、有效钾、有效磷、有效钼、有效锰和有效硼的含量,除了有效磷和有效硼含量较低外,其余均为较高的含量水平。本区土壤Se含量丰富,应加强富硒产品开发利用研究。洞庭湖地区土壤肥力综合评价结果为二级以上的面积占全区总面积的65%以上,土壤肥力高。洞庭湖区土壤中N等肥力元素含量普遍较高,有益于农业生产,适合选择重金属元素含量低而肥力元素含量高的地区作为无公害食品基地的选地。

This paper is rehed on an academic project entitled ＂eco-geochemical survey of Lake Dongting region in Hunan province＂, and is based on the multi-purpose regional geochemical survey of this area. Classification evaluation is conducted on the total or avail- able contents of N, P, K, B, Mo, Mn and Se, moreover, by means of AHP （analytic hierarchy process） method, comprehensive assess- ment of soil fe^lity level in Lake Dongting Region is also accomplished. The result shows that area percentage with abundant or medium total N and K content accounts for 96.5% and 99% while total P content is relatively low. The contents of available N, P, K, B, Mo and Mn are regressed according to regional geochemical statistical principle, except for P and B, other elements are abundant. Se content of the region is noticeably high, in this way, much emphasis should be put in developing products of high Se content. It＇s indicated that the ratio of level 2 or above area reaches 65% in terms of soil fertility. In conclusion, the contents of such beneficial ele- ments like N, K, and Mn are generally high, which is an advantage for agriculture. It＇s also suggested that we should choose farmland with low heavy metal elements contents and high fertilizer capacity for pollution-free food.