The average functionality of soil science in sub-Saharan Africa is negligible because of poor infrastructure and inefficient systems. While most countries operate a national soil laboratory, limited functionality, inappropriate analyses, expense and enormously time-consuming response times is a constraint for use by farmers. SoilDoc is a new diagnostic soil tool that permits in-situ measurements of complementary critical soil properties essential for assessment of the soil fertility and making on the spot management recommendations. SoilDoc utilizes principally commercially available, battery-powered, miniaturized instruments, suitable for use in farmersŐ fields. The results are fed into Android software and a smart phone allowing calculations, interpretations and recommendations to be instantly returned to the user. SoilDoc has been established for utilization by extension agents and agro-dealers working with smallholder farmers in developing countries. Nonetheless, it will also be useful for agricultural consultants in any setting. Challenges being addressed include building calibration dataset for CaCl2 extractable nutrients, embedding automatic quality control measures, developing simplified training materials and building supply chain systems. The parameters include soil pH, electrical conductivity (indicative of general fertility levels), labile organic carbon, and 0.01 M calcium chloride extractable macronutrients, nitrate-N, sulfate-N, phosphate-P and potassium-K. Exploratory data analysis from SoilDoc seems to pick up differences in crop yield and responsiveness to inorganic inputs. Further multivariate analysis checks whether SoilDoc is able to detect/track effect of other management interventions (liming, manure application and deep till).