Description

Supplying crops with adequate nitrogen is vital to ensuring food supplies. Once nitrogen is added to the soil, it is subject to chemical transformations of the nitrogen-cycle including transformation to nitrate. Excessive amounts of accumulated nitrate may then leach out of the soil and could potentially enter and contaminate drinking water supplies. The purpose of this book is to examine the subject of nitrogen management and ground water protection. The issue of maintaining ground water quality is addressed primarily from an agronomic point of view. Topics covered include: health and economic aspects of nitrate in drinking water; nitrate sources; ground water nitrate in the USA and other developed countries; transport, leaching and accounting for nitrogen; soil, nitrogen, crop and water management; and nitrate in aquifer systems. The book contains a keyword index and is organized into thirteen chapters, each with appropriate references, tables and figures. Chapter authors are among the leading experts on the subject of nitrate and ground water quality. Readers to whom the book is directed include soil scientists and agronomists, agricultural engineers (irrigation and drainage), environmental scientists, agricultural policy makers, and hydrologists.

Table of Contents

Dedication. List of Contributors. 1. Ground Water Quality Concerns About Nitrogen (R.F. Follett, D.J. Walker). Introduction. Health concerns. Human toxicity. Economic concerns. Economic concepts. Problem nature and implications for solution. Public policy options. Resource conservation concerns and issues. References. 2. Sources of Nitrate to Ground Water (D.R. Keeney). Introduction. Nitrogen cycling. Natural sources of nitrate. Geologic nitrogen. Forests. Forage and pasteral agriculture. Waste materials. Animal wastes. Sewage sludge and effluent. Septic tanks. Row crops agriculture. Irrigated agriculture. Summary. References. 3. Nitrate in Ground Water in the United States (G.R. Hallberg). Introduction. Nitrate, agriculture and ground water. Nitrate and water quality: a national overview. Comparisons with state data. Surface water and ground water. Nitrate distribution and variability. Depth distribution. Spatial variability and depth distribution. Spatial variability: land use and local sources. Temporal variations. Depth and time. Denitrification and time. Nitrate variability among wells. Summary and conclusions. References. 4. Ground Water Nitrate in Other Developed Countries (Europe) - Relationships to Land Use Patterns (S. Juergens-Gschwind). Introduction. Impact of bare land. Impact of forestry. Impact of grassland. Cut grassland (meadowland). Grazed grassland. Impact of arable crops. Depending on crop type. Depending on type of soil. Depending on rainfall and irrigation. Depending on temperature. Depending on ground water level and drainage. Depending on rate, timing and form of fertilizer use. The impact of horticulture. Intercropping and green manuring. Irrigation. Home and hobby gardens. References. 5. Nitrate Transport and Leaching Mechanisms (W.A. Jury, D.R. Nielson). Introduction. Nitrate transport mechanism. Convection. Diffusion. Hydrodynamic dispersion. Removal and

Details

No. of pages:
412
Language:
English
Copyright:
© 1989
Published:
Imprint:
Elsevier Science
Electronic ISBN:
9780444599391
Print ISBN:
9780444873934

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