The eastern Africa region faces serious and worsening problems of food security, decreasing per capita food production and massive poverty. Agriculture in this region is dominated by smallholder farmers. Yield levels on these farms are generally very low for a variety of reasons. One important reason is the declining soil fertility, and this forms the major theme of this book. Currently the different countries have policies aiming at giving increased attention to achieving improved productivity and better farm incomes as part of their national poverty reduction strategies. This book should provide useful information to extension workers and their trainers in giving the necessary advice to farmers.