In the semi-arid tropical (SAT) regions of India, rainfed agriculture is greatly infl uenced by water shortages caused by low, highly variable and erratic rainfall. In addition to water shortage, crop productivity in these regions is also aff ected by low soil fertility. In the past, little eff ort was devoted to diagnosing and managing the nutrient-related problems in farmers’ fi elds. The on-going integrated watershed management program by ICRISAT and its partners provided the opportunity to diagnose the soil infertility-related problems by soil testing; and to develop nutrient management protocols and determine on-farm crop responses to fertilization in the SAT zone of India.