SOIL FERTILITY CAPABILITY OF UMBRIC GLEYS OLS IN BIGOMBO VALLEY IN NW-TANZANIA

In the Kagera region, wetland soils in swampy valleys have a considera ble potential for food crop production - especially in the dry seasons . In view of the dramatic degradation of organic matter due to agricul tural land use of such Umbric Gleysols, the problems of soil fertility with regard to land use options are discussed. The classification of soil fertility according to the FCC-system, which is often applied in the humid tropics, proves to be only partly suitable. In this system, mainly mid-term variable soil properties are considered whereas the be haviour of organic matter is disregarded. The conservation of the nutr ient pool of the Gleysols depends on the establishment of adequate cro p management in relation to the conservation of their wetland characte r.