The Kenya agricultural sector is an important segment of the national economy generating employme... more The Kenya agricultural sector is an important segment of the national economy generating employment, outputs and incomes. Currently, agriculture directly represents 26 % of the gross domestic product (GDP). Due to the significant contribution of the agricultural sector to the overall economic growth, it is important to invest commensurately in order to meet the targeted growth rate of 6% per year. In trying to expand the agricultural production, farmers face several challenges which include inadequate farm inputs and poor soils. Fertilizers and pesticides are frequently added to soils to supply sufficient nutrients for plant growth which could contribute to environmental pollution. This study was conducted to assess farming practices, agrochemical usage and its potential impact on environment in Uasin Gishu and Homa Bay Counties, Kenya. Field surveys involving key informant interviews and questionnaires were administered to farmers in the study areas of Homa Bay and Uasin Gishu coun...
A single basis of heavy pollution may have severe impact on the health of human beings. Heavy met... more A single basis of heavy pollution may have severe impact on the health of human beings. Heavy metals go into the body system through air, food along with water and some bio-accumulate over a time period. The uptake of heavy metals by plants such as maize (Zea mays) is a path of their way into the human food chain. Pollution of animal feedstuffs with heavy metals can cause negative impacts to animal health and can cause harmful effects to humans through food chain such as consumption of meat and milk products. For that reason, monitoring uptake of excess heavy metals in Zea mays grains and leaves is paramount in avoiding unnecessary exposure. Therefore, this study sets out to determine heavy metal uptake in Zea mays grains as well as leaves in diverse agro-ecological regions farms in Homa Bay County. The average concentrations of Zn, Cd, Cu, Co and Pb in Zea mays grains were 0.113, 0.225, 0.122, 0.042 and 0.324 mg/kg respectively and that of maize leaves were 0.119, 0.041, 0.115, 0...
Maize grain is the second most vital food after wheat to humans and forms an important part of a ... more Maize grain is the second most vital food after wheat to humans and forms an important part of a human diet due to its nutrients. In Kenya, it is estimated that one out of every two acres of land put to crop production is under maize crop. Maize can also be fed whole to livestock (grazed or chopped and ensiled). Due to increased demand and the need for higher productivity, farmers have adopted modern farming methods which include use of fertilizers, pesticides, compost manure, and irrigation. Uses of these products elevate amounts of heavy metals in the soil. Such heavy metals such as lead (Pb) and cadmium when taken up by plants accumulate in the plants becoming toxic at high levels. It is essential to monitor these levels in grains and leaves to ensure they do not exceed the WHO permissible limits. This study aimed at monitoring the levels of heavy metals uptake in maize (Zea mays) grains and leaves is within permissible levels. Level of heavy metals in maize grains from different ecological zones in UG County had mean concentration of Zn 0.122, Cd 0.03, Cu 0.111, Co 0.04, and Pb 0.33 mg/kg. These results were below WHO standards except for Cadmium, Co, and Pb which were slightly higher than recommended standard. The study also found that maize leaves had mean concentration of Zn 0.115, Cd 0.04, Cu 0.117, Co. 0.041 and Pb 0.323 mg/kg. The results were below WHO standards except Co and Pb which had slightly higher levels than the recommended WHO standards. The analytical results from this study provided important baseline statistics on the concentration of selected heavy metals in maize grains and leaves besides being an important assessment of environmental pollution in rural areas where maize farming is predominant.
Intensified agricultural activities in Kenya over the past few years has led to an increased and ... more 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 LM 3 (Lower Midland3) and LM 4 (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,
Uploads
Papers by Walter Machuka