Integration of farmers’ knowledge and science-based assessment of soil quality for peri-urban vegetable production in Ghana

This study, based on vegetable production fields, combined soil quality assessed by three approaches (qualitatively by farmers, semi-quantitatively by a researcher and quantitatively by laboratory analyses) with the aim of improving the integration of the different approaches. We interviewed 79 peri-urban vegetable growers in two communities within the Sunyani Municipality, Ghana. Eight of the farmers were selected to participate in the farmer-based assessment of soil quality. Further, visual evaluation of soil quality was conducted by the researcher, followed by laboratory analyses of soil properties to corroborate the farmers’ assessment of good and poor soils in their fields. Results showed that the farmers used locally-defined characteristics to describe the physical, biological and crop performance indicators of soil quality. There was, in general, limited use and understanding of soil chemical properties as indicators of soil quality. The farmers’ perception on soil quality of their fields largely influenced their decision on the type of crops they cultivate, and application regimes of mineral fertilizers. Results from the visual evaluation by the researcher agreed in some respects with the farmers’ assessment of soil quality of the good and poor soils in their respective farms. Laboratory analyses did not show specific trends for the content of chemical properties for neither good nor poor soils. The study highlighted that none of the approaches of soil quality assessment is necessarily superior in and of itself. We emphasized the need for integration to capitalize on the strengths of each approach, enhance mutual learning between farmers and soil scientists, build the capacity of farmers, and improve their decision on soil use for agricultural production.