This book presents topical research in the study of the characteristics, processes and management of soil fertility in agriculture. Topics discussed include agricultural management changes in Pampean soils related to rotation and tillage; agroforestry systems in the Eastern Amazon; soil and crop management practices in bioenergy cropping systems; evaluation of the potassium supplying abilities of animal manures; nitrogen fertilisation in the modern sustainable farming systems of Moldova; and soil fertility enhancing microorganisms and their application as biofertilisers.