Effects of Sugarcane Farming on Agro-Biodiversity in Mumias Division, Kakamega County, Western Kenya

Abstract

Sugarcane farming is a commercial mono cultural land use practice which can often lead to reduction in agro-biodiversity. Commercial sugarcane farming in western Kenya is cultivated underthree categories: small scale (outgrowers), large scale and nuclear estate. The study was carried out in Mumias division of western Kenya where 68 percent of the land is under commercial sugarcane- cultivation while 32% is left for subsistence agriculture and other land uses.Previous studies carried out in the region did not directly link sugarcane farming to the loss of agro-biodiversity. The objectives of the study were to: identify and compare the diversityof subsistence food crops grown in the study area before and after the introduction of commercial sugarcane farming; assess the effects of commercial sugarcane farming emagrobiodiversity in the study area. There was higher agro-biodiversity in the study area before the introduction of commercial sugarcane farming. The declined when comniercial sugarcane was introduced. Data collection methods included: questionnaires, interviews, field observation and Participatory Rural Appraisal tool for primary data. A sample size of 90 respondents purposively selected from a total study population of 4384 sugarcane farmers in the division. Secondary data was obtained from journals, text books, government reports from the Ministry of Agriculture and newspapers. Quantitative data was analyzed using descriptive statistics such as frequencies and percentages. Qualitative data that was collected through in-depth interview and Focus Group Discussion was transcribed and organized into themes and subthemes. Data was presented in the form of tables and graphs. The indigenous crops grown in the study area before commercial sugarcane farming were established as maize, bambara groundnuts, simsim, sorghum, fmger millet cassava, sweet potatoes, groundnuts, and indigenous sugarcane with maize occupying the largest acreage among small scale farmers. Common indigenous vegetables included, spider plant, jute mallow, african nightshade, pumpkin leaves, sunhemp, african kales and vine spinach. With the introduction of commercial sugarcane farming in the 1970s, the land under subsistence agriculture declined thus affecting agro-biodiversity in the study area in the following ways: vine spinach became extinct, acreages under maize, sorghum, finger millet, cassava and sweet potatoes reduced in 1970s and 1980s and increased in 1990s and 2000s. However, cassava declined in the same period. The research also established that sugarcane farming did not have any effect in the cultivation of groundnuts and bambara groundnuts. Indigenous vegetables normally grown in kitchen gardens and abandoned cattle sheds declined as a result of commercial sugarcane farming. The study concluded that commercial sugarcane farming was one of the major factors that had an effect on agro-biodiversity in Mumias division of western Kenya. Other factors included pests and diseases, change in tastes and preference and introduction of exotic crops such as kales. It is recommended that agricultural extension officers should sensitize farmers to allocate specific portions of land for subsistence crops to ensure food security and conservation of agro-biodiversity.