GIS-AHP Technique Land Suitability Assessment for Capsicum (Capsicum annuum L.) Production

This study was carried out to determine areas best suited for capsicum production in the peri-urban counties of Nairobi, Kenya for growing capsicum (Capsicum annuum L.). The study used a multi-criteria evaluation approach by applying the Analytic Hierarchy Process (AHP). These methods involved a selection of various criteria used for analysis and categorized according to their usefulness concerning capsicum growth conditions/requirements. 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 Saaty’s table. The cumulative weights were used to construct output maps using Quantum Geographic Information Software (QGIS). A 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. 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 crop due to the presence of some limitations such as texture, soil pH, drainage, and climate.

• About 50% of land in Kiambu County, 8% in Kajiado County, and 12% in Machakos County are suitable for capsicum production.

• Soil pH, drainage, texture, and climate are the key limitation for declining capsicum yields.

• Optimizing capsicum production is possible through sustainable farming, which entails the production of a crop in a conducive and suitable environment.

• Geographic Information System (GIS) is used to support decisions for development in agriculture by providing information that helps farmers to optimize crop production.