ERODIBILITY INDICES UNDER DIFFERENT LAND USES IN AWKA, NIGERIA

Erosion problems are on the increase, worldwide, especially in the Southeastern part of Nigeria, where this problem is becoming uncontrollable. In this study, erodibility indices were studied in Nnamdi Azikiwe University, Awka, Anambra State Nigeria under four land uses (cultivated land, fallow land, bush and bare land). The land uses are located in the Agricultural and Bioresources Engineering Farm Workshop, apart from the bush, which is located close to the farm workshop. Soil samples were collected from each of the land uses at 0-25cm depth using soil auger. The soil samples were taken to the laboratory for determination of %silt, %clay, %sand and organic matter content. Soil structure, permeability, clay ratio (CR), modified clay ratio (MCR), critical level of organic matter (CLOM) and erodibility (K) index were also determined. From the result. %sand and % silt had negative correlation with k index, while % clay and organic matter content has positive correlations. The average CR and MCR obtained were 2.303 and 1.98 respectively, while CLOM of soil obtained in all the land uses were less than 5%. The result of the CLOM indicates poor soil structure and high susceptibility of erosion, while conclusion could not be drawn from CR and MCR.