This paper attempts to provide an ex-post assessment of the field level impact and economic viability of the SRRP using the empirically derived estimates of the average income impacts that the application of bentonite or clay technology has generated among farm communities in Northeast Thailand. These impact estimates for the sample area are based on household survey data collected from a sample of 250 farmers, representing three farming systems, i.e., vegetable farms, organic rice farms and integrated farms. The estimates for the region (Northeast Thailand) are based on a mix of secondary data, opinion of experts, and information from farmers. The impacts are evaluated only in terms of the net income associated with the application of clay technology and the evaluation does not cover other direct and second-round benefits related to food security, resource conservation, farm diversification and livestock development. Finally, given the specific nature of the soil problem and the predominance of rainfed farming in the region, the impact, as assessed here, also captures the effects on yield and crop pattern of the improved soil water holding and nutrient capacity as achieved through clay application.