Properties of potassium loss from red soil slope land in different farming systems
不同农作措施下红壤坡耕地土壤钾素流失特征的研究

The properties of potassium loss in red soil slope field under six cultivations were studied. The results showed that potassium lost mainly with bed load and runoff on surface of soil. The potassium lost mostly with runoff in slope field under contour, contour dam cultivated ways with less sediment except the fallow, under which the loss of potassium with bed load equaled to the loss of potassium with runoff. The potassium lost mostly with bed load in slope field under straight, grass strip and contour ditch cultivated ways with more sediment, and particulate potassium was the main form of potassium lost in runoff. Compared with straight cultivated way, other cultivated ways reduced soil potassium loss significantly. Contour, fallow, and contour dam cultivated ways were better than straight and grass stripe cultivated ways on controlling potassium loss. In the year of 2000, the potassium loss was mainly occurred during May to August accounting for 87.24-100% of total annual lost.