In natural ecosystems, nitrogen (N) is in short supply and an important control of numerous ecosystem functions. Understanding the N cycle is imperative to improve capacity to meet global N demands while reducing environmental impacts. The natural N cycle has been disturbed by the industrial process of fertilizer production resulting in climate change and global warming. This book discusses availability, production, and recycling of N in air, water, plants, and soils. It features information on N impacts to soil and water quality, management of N in agroecosystems, and techniques to maximize the use efficiency while minimizing the risks of leakage of reactive N into the environment.