Soil Nitrogen Uses and Environmental Impacts. 2018, 2021. Rattan Lal and B. A. Stewart, editors. CRC Press, Boca Raton, Florida. 379 p. $43 paperback, $152 hardback. ISBN 9781032095653.
The book has fifteen chapters covering the topics in the global nitrogen cycle, the use of nitrogen-containing fertilizers, and the effects of fertilizer use on the environment of the World. Each chapter is an independent one, and the text is not divided into sections of related topics. The chapters cover general topics of management of nitrogen in soil and specific topics in management of nitrogen in geographic regions of the World. Each chapter is documented heavily with references to support the content of the text.
Rattan Lau is Distinguished Professor of Soil Science at the Ohio State University, Columbus, Ohio. He is the winner of the 2020 World Food Prize. B. A. Stewart is Director of the Dryland Agricultural Institute and a distinguished professor at West Texas A & M University, Canyon, Texas. The authors of the chapters are scientists from universities, research centers, governmental agencies, and industries throughout the World.
Chapter 1 Benefits and Unintended Consequences of Synthetic Nitrogen Fertilizers is an introductory chapter and deals with the history of nitrogen fertilization and statistics on the use of nitrogen-containing fertilizers. The chapter notes that huge amounts of nitrogen fertilizers will be required the feed the population of the World. With added fertilizer, improved varieties, and good farming practices, grain yields of corn have increased almost linearly since about 1950. The data show, however, that application of nitrogen fertilizers has not increased since the middle 1970s. Much of the chapter addresses the consequences of fertilizing crops for food production and yet managing protection of the environment from over use of fertilizers.
Chapter 2 Nitrogen Fixation by Pulse Crops and Use of Nitrogen Isotopic Techniques to Measure the Fixation Capacity addresses the production of grain legumes and the effects of these crops on the requirement for nitrogen fertilizers. The chapter covers methods of measuring of the fixation of nitrogen by grain legumes.
Chapter 3 The Role of Nitrogen Stable Isotopes to Investigate Soil Nitrogen Transformations and Cycling in Agricultural System provides an overview of the nitrogen cycle, nitrogen inputs and their effects on nitrogen in the soil, nitrogen-use efficiency by crops, and nitrogen losses from the soil. Considerable attention is given to studies of the relations of farming practices and environmental changes on nitrogen transformations in the soil and nitrogen-use efficiency.
Chapter 4 Nitrogen Loss in Snowmelt Runoff from Non-Point Agricultural Sources on the Canadian Prairies addresses agriculture and fertilization practices in Manitoba, Alberta, and Saskatchewan. Attention is given to the losses of nitrogen in runoff of melting snow.
The chapter on Denitrification in Soil (Chapter 5) is a detailed presentation of enzymology and genetics of denitrification and of the organisms that conduct the process. The chapter also covers the regulation of denitrification and effects of factors such as oxygen, carbon, nitrogen, and environmental conditions on the process. The effects of soil management including tillage, fertilization, liming, irrigation, and use of pesticides on denitrification in soil. The chapter presents studies of effects of ecosystem scales on denitrification and methods of measurement and assessment of denitrification.
Chapter 6 covers Nitrogen Balances and Nitrogen use Efficiency in the Nordic Countries. It notes that a large surplus of nitrogen exists in soils of Norway, Sweden, Finland, and Denmark and discusses practices and regulations that might be used to increase efficiency of nitrogen use and limitations of nitrogen loss from farmland.
Chapter 7 addresses nitrogen balances in Intensive Dairy and Beef Operations. It discusses the safe and productive use of excreta of cattle in mixed cropping and grazed farms, intensively grazed pasture farms, and confined animal feeding operations.
Chapter 8 addresses Efficient Nitrogen Management in the Tropics and Subtropics. It covers issues nitrogen fertilization including nitrogen-use efficiency, losses of fertilizer nitrogen on farmland, and management of nitrogen fertilization. It covers also agronomic practices of soil and crop management on nitrogen-use efficiency in farming in tropical and subtropical regions. The next two chapters cover nitrogen management in specific geographic regions. Chapter 9 is titled Enhancing Soil Organic Carbon by Managing Nitrogen in China and covers the effects of nitrogen fertilization on the labile soil organic matters in the soils of China. Chapter 10 is titled Managing Nitrogen in Small Landholder Hill Farms of North Eastern Indian Himalayas, which is a region of subsistence agriculture on ecologically fragile land and in a wide range of climates.
Chapter 11 is about the Merits and Limitations of Enhanced Efficiency Fertilizers. Enhanced efficiency fertilizers are ones that are designed with limited release of nitrogen or ones that inhibit a part of the Nitrogen Cycle. The text summarizes information on the types these fertilizers concerning their effects on crop yields, nitrogen-use efficiency, and losses of nitrogen into the environment. Several tables are used to present this information. The main text of the chapter covers specific fertlizers and inhibitors. Chapter 13 adds to this presentation with text on Formulations of Slow Release Fertilizers for Enhanced N Use Efficiency.
Chapter 12 covers Economic and Policy Implications of Nitrogen Management. Topics include problems with nitrogen deficits and excesses in applications, economics of nitrogen use, policies for regulating use of nitrogen, and on-the-farm decisions concerning use of nitrogen-containing fertilizers.
Chapter 14 Managing the Soil Nitrogen Cycle in Agroecosystems discusses strategies for reaching a neutral impact of nitrogen fertilization on planetary nitrogen balance. Chapter 15 Nitrogen: Managing the Necessary Evil adds to this discussion.
This book has very good content on the Nitrogen Cycle and nitrogen management in fertilized soils. It gives a good balance of knowledge concerning crop production and environmental concerns. This information will be of interest to teachers and researchers in plant and soil sciences. Each chapter presents text that address the topic, and the text is documented well with references that readers can consult.