The project will develop a decision framework that will build on past experimental data (i.e., fertilizer response trials, integrated soil fertility management (ISFM) field trials) and new ISFM experimental trials in selected sentinel sites. Legacy data from field trials throughout Africa will initially be used to identify the key factors that determine crop responses to various soil management practices and systems. New experimental trials will be established in selected sentinel sites in four countries (Malawi, Mali, Nigeria and Tanzania; for Kenya we will use existing ongoing trials) to test and to document responses to locally adapted soil management recommendations.