Integrated Nutrient Management (INM) is an important strategy for soil improvement in smallholder systems of East Africa but successful implementation depends upon identification of opportunities for intervention, which are in turn dependent upon a practical knowledge of farm enterprises and decision making. Surveys addressing soil fertility management were conducted among 190 households in the Central Kenyan Highlands. Farmer-available organic resources were collected during these interviews and later analysed for plant nutrients. The business strategies of 139 retailers of agricultural supplies were assessed through a 23-question survey conducted in 17 districts in the Kenyan highlands. These surveys provided background for identifying promising interventions by farmers to improve soil fertility and for retailers to meet farmers' demands. Soil fertility depletion results from both internal and external flows of nutrients and is often expressed as nutrient deficient patches in farm "outfields". An approach to improving INM separates management practices into four general categories; nutrient recycling, livestock-crop interactions, biological nitrogen fixation and fertiliser use. Fifteen specific farmer practices as candidates for strengthening INM were identified within these four categories. Our findings suggest that farmers in the Central Highlands of Kenya are practising the fundamentals of INM but their efforts are restricted by the availability of organic resources and investment capital.