Epsilon Archive for Student Projects

Abstract

The soils ability to produce food is important in all parts of the world. The soils used for food production in Kenya are threatened by different factors, such as soil degradation due to erosion, lack of nutrients, and scarcity of water. The aim of the study was: (1) to obtain background information related to Kenyan small hold farming, focusing on the farmer’s experience of productivity and erosion, and (2) to measure soil physical properties and field characteristics as part of a field study conducted over a short period of time.

This study was conducted on eight farms in the Embu district, in central Kenya. The study was divided into three parts: study of farming in the Embu district, study of soil physical properties and their correlation to productivity, and a study of soil erosion. The first study was done through observation and interview. It showed that farming was done with simple methods. The most common crops were: maize, beans, bananas, coffee and tea. The farms were small, around one hectare with small fields of about 1300 m2.

The following soil physical properties were compared between fields with high and low productivity, respectively, within the farms: soil texture, plant available water capacity and infiltration capacity. The carbon content was also compared. There were no statistically significant differences in the mentioned physical properties and carbon content between the high/low producing fields. The reasons for this might be that: farms are small and the soil physical properties homogenous, yield data was too uncertain or other soil properties affect the productivity. The texture was rich in clay and the plant available water had an average of 21% of the soil, which is ideal for maximal root growth and function. The average carbon content for the area was 2.0%, which is good for African soil and the average infiltration capacity was 330 mm/h, which is rapid. This showed that infiltration and plant available water was not limiting for the crops.

The erosion study compared sites on the farms which had much and little erosion, respectively. The compared factors were: silt content, slope steepness and infiltration capacity. There were no statistical significant differences in the mentioned factors between the sites with much and little erosion. The average soil loss for the region was calculated to 80 ton ha-1 year-1 using the Revised Universal Soil Loss Equation (RUSLE).