A substantial potential exists for improving rain fed agriculture in Senegal. Thus concludes this study, which analyzes the relationships among precipitation levels, growing season lengths, and potential agricultural yield in that country. The study begins by determining monthly dependable precipitation levels and mean annual rainfall at 57 different locations in Senegal. Next, a mathematical model is used to predict growing season length for various rain fed crops. The selection of crops climatically suited to Senegal is then assessed, and the country is divided into six zones with fairly uniform climates and moisture regimes; water management, land preparation, and cropping systems suited to each zone are described. Finally, means of optimizing production are summarized. Appendices include a report on the methodology employed and detailed 30-year climatic information for 5 locations.