Heavy Metal Concentrations in Agricultural Farms in Homa Hills Homa Bay County, Kenya

Intensified agricultural activities in Kenya over the past few years has led to an increased and persistent use of fertilizers, pesticides, manure, use of machinery in order to increase yield for economic development and achieve the goals of vision 2030. Large quantities of agrochemicals are regularly added to soils in intensive farming systems to provide adequate nutrients for plant growth. The compounds used to supply these elements contain trace amounts of heavy metals (e. g. , Cd and Pb) as impurities, which, after continued fertilizer application may significantly increase their content in the soil. There is need to study impact of intensive use of use of agrochemicals in the farms. Therefore, this study set out to determine the concentrations of the different heavy metals in the soil from agricultural farms of Homa Hills, Homa Bay County. The soil samples were obtained from two agro-ecological zones LM3 (Lower Midland3) and LM4 (Lower Midland 4) zone, around the areas of intense maize farming. Six farms in each zone were randomly selected to obtain soil samples. Sampling was done twice, for the dry and wet seasons. Different samples were also collected at two different sampling depths (0-10cm and 11-20cm) for each sampling point. The concentrations of selected heavy metals for each sample were determined using Inductive couple plasma. Data was presented using tables and figures. T-test was used to compare the variation of heavy metal concentration in the different agro-ecological zones and the different sampling depths. The results obtained showed that the mean concentration of Pb, Cd, Co, Zn and Cu ranged between 17.731.7 ppm, 7.38.3 ppm, 2.55.0 ppm, 4.530.5 ppm, 10.713.3 ppm respectively in LM3at the depth of (0-10cm and 11-20cm). In LM4 the mean concentration of Pb, Cd, Co, Zn and Cu ranged between17.7535.5 ppm, 7.088 ppm, 4.95.3 ppm, 4.2517.16 ppm, 12.4119.25 ppm respectively at the depth of (0-10cm and 11-20cm. The concentrations of Zn, Cd, and Pb in soil sample exceeded WHO limits. The 1020 cm depth had higher concentrations as compared to 010 cm sampling depth this could be due to leaching of heavy metals to the lower strata. Finally, the concentrations were higher during the wet season as compared to the dry season. From the findings, farmers are from this area are advise to avoid using chemicals that introduce such elements to the soil.