The effect of soil erosion on soil productivity of humic nitisol, Kabete

Abstract

Soil erosion and its effects on soil productivity of a humic nitisol was studied during 1987 second season and 1988 first season .. The runoff plots which·measured 10 m x 2 m were set up at two different slopes of 10% and 16%. The treatments were maize/beans intercrop and bare land (control) in three replicates. The amount of rainfall was recorded for each rainfall storm event. In addition, the volume of runoff for each effective storm was recorded. For both the runoff and eroded sediment samples were erie l.ysed for the nutrient ni trogen, organic carbon, phosphorus and a few bases. During the investigation the following losses per hectare were reported. Soil loss was 0.1 to 69.9 tonnes, runoff 0.13 to 48.75 mm, nitrogen 0.51 to 125.1 kg; carbon 1.3 to 252.2 kg; phosphorus 0.001 to 11.25 kg; sodium 0.119 to 7.844 kg ; Potassium 0 to 4.312 kg ; Calcium 0 to 16.417 kg ; Magnesium 0.414 to 8.640 kg. These results indicate a great loss of soil" nutrients due to soil erosion. Also the physical and chemical properties of the eroded sediment were studied. Nutrient enrichment ratio for nitrogen, phosphorus and organic carbon was> 1.0. The particle size distribution ratio also did change.