This book will address the major subsoil physical and chemical constraints and their implications to crop production; Plant growth is often restricted by adverse physical and chemical properties of subsoils yet these limitations are not revealed by testing surface soils and hence their significance in crop management is often overlooked. The major constraints can be physical or chemical. Physical limitations such as poor/nil subsoil structure, sandy subsoils that do not provide adequate water or gravelly subsoils and, etc. On the other hand, chemical constraints include acidity/alkalinity,high extractable AlorMn, low nutrient availability, salts,boron toxicity and pyritic subsoils. Some of these constraints are inherent properties of the soil profile while others are induced by crop and soil management practices. This aim of this book is to define the constraints and discuss amelioration practices and benefits for crop production. This book will be of interest to readers involved with agriculture and soil sciences in laboratory, applied or classroom settings.