Effects of soil erosion on sediment dynamics, food security and rural poverty in Makueni District

Abstract

Makueni District has experienced low crop production per unit area despite increased hectarage under crop production. The district relies heavily on farming for food and income generating activities for the households. However, poverty level has been on the increase due to poor crop production and limited diversity in sources of income. Analysis of field survey carried in the district shows high variability of soil nutrients (Nitrogen, Phosphorous, and potassium), Cation Exchange Capacity (CEC) and soil pH due to various land use systems which have been in use for a long time. These land use systems have contributed to land degradation and increased sediment fluxes from farm lands. Subsequently, food production has declined by 50%due to soil fertility decline leading to increased household poverty levels. This is based on a survey study carried in the district between the year 2005 and 2008. The district has also experienced increased sediment influxes problem in water supply systems. These have affected immensely water sources in the district namely, earth dams, water pans, traditional river wells among others. Continued sedimentation of these water sources has compromised the quality and quantity of water supply in the district and therefore, changing the socio-economic characteristics of many households. Increased sediment load is attributed to poor methods of farming and grazing such as lack of contours, cut off drains, terraces and overgrazing. This paper examines soil erosion incidences, intensity of land