Epsilon Archive for Student Projects

Abstract

In the past 50 years, the demand for food, fuel, timber, fibre and fresh water has increased in East Africa. Because of this, the high growth rate of the population and the economic dependence on agriculture, large areas in Kenya have been deforested. One way to reconstruct the ecosystem and compensate for the loss of resources is to design farming systems that can help safeguard these demands, e.g. agroforestry systems. This study, which was carried out in the West Songhor district, Western Kenya in January-March 2010, compares the impacts on the soil and on the household situation of two different farming systems (sugarcane farming and agroforestry) from an environmental, ecological, social and economic perspective. To investigate these factors, 21 farms were visited for semi-structured interviews and topsoil samples were taken for bulk density determination and carbon and nitrogen analysis. This was followed by in-depth interviews with eight of the farmers, in which a seasonal calendar and field gate nitrogen balance were constructed to obtain information about the situation on the farm during the previous year (2009). In addition, soil pits were dug on these six farms, a soil profile description was carried out and bulk density samples were taken from different horizons. All 21 farms studied were located around the same village, Kopere. The results showed an improvement in soil under agroforestry, as indicated by increased carbon and nitrogen concentrations in the topsoil and decreased bulk density in the agroforestry systems. The agroforestry systems without manure had a significant difference in the carbon and nitrogen concentrations compared to the sugarcane systems. For the household situation, the differences between the two farming systems depended greatly on the utilisation rate of resources generated by these farming systems. The agroforestry system generated many more products, such as firewood, timber, fruits and seedlings, than the sugarcane system. These products helped improve the livelihoods of households practising agroforestry in terms of income distribution throughout the year, but overall income was lower than with the pure sugarcane system. Overall, the most important factor as regards differences between these two farming systems studied proved to be knowledge of how to implement the system and how to utilise and conserve available resources.