Soil fertility assessment and management from the perspective of farmers in four villages of eastern South Africa

Understanding farmer perceptions of soil fertility is necessary for the development of appropriate assessment methods for sustainable agro-ecosystems. This study investigated farmer perceptions of soil fertility and management in four villages of eastern South Africa. A questionnaire was administered to 50 farmers from each village to obtain a general overview of local soil knowledge as well as soil fertility perceptions and assessment. Ten farmers were then chosen from each village for in-field walks and to gather in-depth knowledge of local soil fertility concepts, soil-crop associations and soil management. During in-field walks, farmers were asked to identify fertile, moderately fertile and low soil fertility plots in their fields from which topsoil samples were taken for laboratory fertility analysis. Local soil fertility descriptors included crop performance and yield, soil texture, stoniness and consistence. Using these descriptors, farmers have developed specific soil use and management practices. There was generally poor agreement between farmer qualitative assessment and measured chemical fertility parameters. However, the study revealed that the generally ignored local qualitative soil knowledge of farmers could be linked to crop performance and potentially supports laboratory soil analysis in terms of its implication for smallholder agriculture in remote areas. The descriptors identified and overall assessment used by farmers in this study reflected considerable soil knowledge employed in daily decision-making. Action learning and research that links local soil fertility descriptors to soil acidity and specific soil nutrient levels is thus recommended for effective identification of yield-limiting factors for sustainable crop production in low-input agriculture.