ON-SITE EFFECTS AND COST OF FERTILITY EROSION FROM FIVE SMALL RESERVOIR CATCHMENTS IN THE UPPER EAST REGION OF GHANA

A study was carried out in the Upper East Region of Ghana to assess the on-site effects and the cost of fertility erosion from five small reservoir catchments (Dua, Doba, Zebilla, Kumpalgogo and Bugri). The catchment soils and reservoir sediments were sampled and analyzed for their bulk density and nutrient content. The mean reduction in soil depth in the various catchments was 3.996±3.806 mm y-1 in the order of Kumpalgogo>Dua>Bugri>Zebilla>Doba. The corre-sponding decrease in the water holding capacity of the top 20 cm depth of the catchment soils ranged from 0.563 to 4.698 % per year. The percentage loss in the total nutrient stocks in the top 20 cm of the catchments as eroded sediment-bound nutrients ranged from 9.63 to 64.71, 7.87 t