The use of simulation models is a necessity and also an aid in the decision-making process in sustainable agricultural systems. Organizing the experimental knowledge of crop production systems without the book keeping and deductive methods of mathematics is very difficult. This book aims to guide readers in the process by which the properties of the systems can be grasped in the framework of mathematical structure with minimal mathematical prerequisites. The objective of this book is to help the undergraduate, graduate and post-graduate students in the disciplines of agronomy, plant breeding, agricultural meteorology, crop physiology, agricultural economics, entomology, plant pathology, soil science and ecology (environmental science). This book may also be useful for administrators in various agricultural universities in order to direct research, extension and teaching activities. Planners at national and state levels may also benefit from this book.