A major challenge on smallholder farms is the tremendous heterogeneity of soil properties. This is at the same time an opportunity, as it is now feasible - at fine resolution - to quantify variability of soil organic carbon and other properties on farmer fields. This can provide unique insights for moving beyond conventional agriculture, which has largely relied on the use of large doses of inputs and average values. Alternative approaches are needed, ones that embrace heterogeneity rather than smooth it over. Two such alternatives are precision agriculture and ecological nutrient management. Such approaches can benefit from harnessing citizen science, open data and inexpensive monitoring. Specifically, on-farm, participatory experimentation can facilitate communication with farmers through local data, and generate new insights about soil processes and thresholds for crop and soil response as well as management options. Use cases are needed to document this process of integrating fine grained local soils data to improve knowledge and farmer decision making.