Nitrogen is the nutrient element applied in the largest quantity for most annual crops. However, crop response to N fertilizer is influenced by factors such as N fertilizer management in relation to plant development, soil type, crop sequence and climatic conditions. Thus, either alternative fertilizer sources or better management of conventional urea fertilizers should be sought. Limited number of researches on some parts of the world have been done so far on the newly released slow release urea fertilizers. Stunning results have been found out from the scrupulously carried out research outputs being revealed in this book. Reading this book is absolutely worthwhile to understand effects of slow release nitrogen fertilizers as compared to conventional nitrogen fertilizers on plant nitrogen uptake and yields of wheat and Teff crops on the highland Vertisols.