A comparative study of organic and conventional farming in Kalama division of Machakos district, Kenya
Langat, Chepngeno Hellen
MetadataShow full item record
Kenya's population growth rate of 2.9% is said to be among the highest in the world, which therefore calls for increased food production in the country. This has resulted in intensive use of land due to continuous cultivation to meet the increased food demand and therefore pressure on the land resource and a decline in soil fertility. The realization of continuing soil fertility depletion in smallholder farming systems has led to a call for an alternative approach to nutrient management. This study aimed to assess the effect on soil fertility by different management practices in Kalama division of Machakos district and the possible contributions of organic farming as an investment to the natural resource capital base. In this study an interview schedule was used to obtain general information about the farmers in order to asses the extent to which organic farming is carried out in the area. The organic farms, which were sampled, were selected using the random sampling method while the conventional farms were selected using the stratified random sampling method from those farms adjacent to the organic farm. Soils were analyzed for N, P, K, Ca, Mg, CEC, organic P, N and C. Bulk density, porosity, texture, and water content, moisture retention and release and microbial biomass were tested for. The primary data generated was subjected to statistical analysis using Statistical Package of Social Scientists version 6.1 (SPSS 6.1). Linear regression (Confidence Level 95%) was used to test the strength of the relationship between variables such as pH and soil nutrients, CEC and soil nutrients and C and soil nutrients. A two-tailed t test was carried out, with confidence levels set at 95%, for the following variables: pH, EC, CEC, Na, Mg, Mn, Ca, N, C, P, Fe, and Zn. The study found that the farm holdings of the study area are small. Owners of smaller sized farms were more likely to practice organic farms than those with larger farms. The largest organic farm was found to be 1.5 acres while the largest conventional farm was found to be 6 acres. Organic produce in the area is not certified and hence there is no difference in marketing and pricing of this produce. Organic farming is therefore practiced in a local sense and to a very small extent as farmers only do it on small pieces of land and have no marketing strategy for their produce. When subjected to a t - Test pH, EC, K, Zn and Fe showed significant differences between organically managed farms and conventionally managed farms with p values being 0.029, 0.024, 0.01 and 0.005 respectively (p< 0.05). The strength of the relationship between pH and K, P, Fe and EC indicated that pH accounts for 57%, 47%, 54% and 60% of the variation in K, P, Fe and EC respectively when subjected to linear regression. Na on the other hand accounted for 46.2% of the variation in EC. Generally the nutrient levels in organic farms was higher than those of conventional farms and therefore a conclusion can be drawn that organic farming is improving soil capital base but may take a longer time for other aspects of soil fertility such as moisture retention ability of the soil to differ significantly. Organic farming should therefore be advocated for in order to improve soil fertility in the area and the food security in the area.