This manual is constructed to progress from a broad discussion of nitrogen in the environment to the concepts using biological processes to control or remove nitrogen, and finally to the details of designing specific systems.

The production of food and energy interfere with the natural nitrogen cycle of the earth. Many of these changes are beneficial, while others are detrimental to societies and the environment. The changing nature of nitrogen in the global environment crosses scientific disciplines, geographical boundaries and political divisions and challenges the creative minds of natural and social scientists, economists, engineers, business leaders and planners. The papers in this book give readers a panoramic view of the changing nature of reactive nitrogen in the global environment, enabling them to make better choices about nitrogen management in food production and consumption, energy production and use, and environmental protection.

One of the main approaches for safeguarding food security, sustainable development has increased demand for knowledge on fertilizer management in crop production. Among essential plant nutrients, nitrogen is one of the most important yield-limiting nutrients, mainly responsible for determining yield and yield components in cereals and legumes. It i