用田间实测法研究我国亚热带土壤的可蚀性K值

本文在自然降雨条件下用全裸地小区田间实测了我国亚热带七种有代表性的不同类型土壤可蚀性Ｋ值。结果表明这七种不同类型土壤间的Ｋ值差别很大，其中紫色和红砂岩发育的耕种普通红壤的Ｋ值最大，分别达到０．４４４和０．４３８，最小的是第四纪红色粘土发育的红色土，其值只人０．１０４，还不到紫色土Ｋ值的１／４。我们变用国际上十分流行的诺谟图方法估算了这七种不同类型土壤的可蚀性Ｋ值，其中有二类土壤用这种方法所估算的Ｋ

SOIL ERODIBILITY FACTOR K AS STUDIED USING FIELD PLOTS IN SUBTROPICAL CHINA

In the work soil erodibility factor K of seven different types of soil in subtropical China was studied using field plots under natural rainfall condition. The field plots were established in Yingtan of Jiangxi Province. The results showed that there were great differences among soil erodibility factor K of seven different types of soils. Among them calcaric regosols developed on purple shale and cultivated cambisol on red sandstone had the highest factor K, being up to 0.440 and 0.438 (0.132 k.hr/MJ. mm) respectively. The lowest was eroded acrisols derived from Quaternary red clay, with factor K of only 0.104, being less than 1/4 of the factor K value of purple soil. The soil erodibility factor K of seven types of soils were also estimated by using the Wischmeier's nomography. These results showed that the factor K vaules of two types of soils estimated by the nomography were close to those measured using field plots, one of the seven types of soils had a bigger difference between the factor K obtained by the above two methods, three had a big difference, and one couldn't be estimated by the nomography. Therefore, the nomograph method for estimating soil erodibility factor K was almost unsuitable for the soil types in subtropical China.