Assessing the Suitability of Selected Areas in Kiambu, Kajiado and Machakos Counties for the Production of Capsicum (Capsicum Annuum L.)
Otieno, Michelle Awuor
MetadataShow full item record
Evaluation of land is a process by which land appropriateness is identified for its capabilities to grow a certain crop in any piece of land. This study aimed at assessing land in the peri-urban counties of Nairobi (Kiambu, Kajiado and Machakos) for growing capsicum (Capsicum annuum L.). Capsicum production in these counties has been doing well until 2014 when the production started to decline. The potential of land to produce capsicum is not known; farmers continue to grow capsicum without clear guidelines. It is for this reason that this study was carried out to determine areas best suited for capsicum production for improved production and to determine limitations that exist in crop production in these regions. To determine suitable areas for capsicum production in the three counties, Soil (pH, drainage, texture and electrical conductivity), climate (temperature and rainfall), and topography (slope and elevation) were the main criteria selected from the literature for the study. The AHP was used to determine the relevance of a criterion based on its cumulative weights as per the Saaty’s table. The cumulative weights were used to construct output maps using Quantum Geographic Information Software (QGIS). Crop suitability map was produced through overlaying of the different thematic maps and suitability levels were based on Food and Agriculture (FAO) land suitability classification. An extensive data set was utilized in the study, both primary and secondary data. The datasets were derived from climate data, soil data and satellite imagery themes. The study used a multi-criteria evaluation approach by applying the Analytic Hierarchy Process (AHP). These are procedures utilized in the GIS environment to evaluate the suitability of land for a particular use. These methods involved a selection of various criteria used for analysis and categorized according to their usefulness concerning capsicum growth conditions/requirements. Soil samples were collected and analysed for both major and minor nutrients (nitrogen, phosphorus, potassium, calcium, sulphur, magnesium, iron, manganese, boron, copper and zinc), then the data was used to generate a soil fertility map for the three counties. Soil nutrients differed significantly across the counties. Nitrogen and organic carbon were deficient in both Kajiado and Machakos counties while phosphorus was in adequate amounts in the soil but not sufficient enough to meet the requirements of the crop. The results showed that about 50% of land in Kiambu County, 8% in Kajiado County and 12% in Machakos County is suitable for capsicum production. The remaining areas were reported unsuitable for the production of the capsicum due to the presence of some limitations such as texture, soil pH, drainage and climate. A fertilizer program for growing capsicum was produced to help farmers in their planning schedules. In the program, urea, manure and triple super phosphate (TSP) were recommended at different rates to address the low nitrogen, organic carbon and phosphorus in the soils. To improve on the suitability and production of capsicum, there is a need to address the limitations experienced in the counties.