Soil and nutrient loss from soil degradation in the Western Tropical Highlands of Cameroon: evidence from stream flow data of river Mewou (South Mifi) and implications for long term agricultural productivity

Abstract This study aims at determining the impact of soil and nutrient loss from the soil exported by the Mewou river on the southern Mifi (Western Cameroon), their implication for long term agricultural productivity and to identify measures to limit these losses and maintain soil fertility. The average exported soil varies in t/km2 from 195.34 in 2011 to 256.015 in 2012. Results for exported physico-chemical parameters indicate that the following parameters : OM, OC, TP, PO4 3-, TN, NH4 +, Ca2+, Mg2+, K+, Fe3+, Al3+ and SO4 2- obtained from wastewaters of the Mewou had a general decreasing tendency from 2011 to 2012 indicating soil depreciation. The variation of water flow and chemical parameters were each characterized by a general equation with a curve of the order: We recommend the use of the Vetiver (Chrysopogon zizanioides) hedges to reduce soil erosion, leaching of cations from the soil exchange complex and to enhance the recharge of the water table; planting density will be a function of the slope of the land concerned. In addition, farmers would grow the hedges along the contours. This will delay runoff and enhance recharging of groundwaters through increased infiltration and reduce soil loss and thus increase agricultural productivity and flow rate.