Synopses & Reviews
Large quantities of nitrogen fertilizer are often applied to grassland with the aim of increasing the production of milk and meat from ruminant livestock. However, less than 25% of the fertilizer N is actually converted into animal protein. The remainder is subject to a variety of transformations in the soil, either before or after its uptake by the grass and consumption of the grass by livestock. Some of these transformations cause loss of N from the soil-plant-animal system, and result in some degree of pollution and potential harm in the wider environment. In this book the published information on the various transformations of nitrogen in temperate grassland systems is comprehensively reviewed. The effects of soil, weather and management factors are discussed and considerable emphasis is placed on soil-plant-animal interactions. The book also discusses the factors that influence the response of grassland to the application of fertilizer N, and how the optimum rate of application may be determined. In addition, N balances are described for different grassland systems, showing how annual inputs and outputs vary greatly depending on sward type and management. Overall, the book presents a valuable review of grassland nitrogen in temperate regions for advisers, researchers, teachers and students in agriculture and environmental science.
"... a must for ecologists and plant and animal agriculturalists, managers, and advisors working in intensively managed sown pastures, particularly in many parts of Europe. It is a fine example of a blending of basic and applied research placed in a format understandable even to producers--one that I would consider handing to many western U.S. ranchers who are highly skeptical about why one would ever want to measure something like ammonia volatilization." --Ecology
This books provides a comprehensive overview of grassland nitrogen incorporating information from crop science, soils and fertilizers, ruminant consumption and environmental aspects. The published information is reviewed on the various transformations of nitrogen in temperate grassland systems. These include those taking place in soils. The effects of soil, weather and management practices are discussed and considerable emphasis is placed on soil-plant-animal interactions. A second aim of the book is to describe the factors that influence the response of grassland to the application of fertilizer nitrogen, and how the optimum rate of application may be determined.In addition, nitrogen balances are described for different grassland systems, showing how the annual inputs and outputs vary greatly depending on sward type and management.The book is of interest to a wide readership, especially those engaged in research, teaching and advisory work, and students taking courses in agricultural and environmental sciences.
Includes bibliographical references (p. 311-381) and index.
Table of Contents
Notes: units, terminology, abbreviations
2. Grasses: Uptake of Nitrogen and Effects on Morphology and Physiology
3. Legumes: Biological Nitrogen Fixation and Interaction with Grasses
4. Consumption, Digestion and Excretion of Nitrogen by Ruminant Livestock
5. Amounts, Sources and Fractionation of Organic Nitrogen in Soils
6. Mineralization, Immobilization and Availability of Nitrogen in Soils
7. Leaching of Nitrogen from Soils
8. Volatilization of Ammonia
9. Volatilization of Gaseous Nitrogen and Nitrogen Oxides through Denitrification and Nitrification
10. Use of Fertilizer Nitrogen and Slurry Nitrogen on Grassland: Recovery and Response
11. Response to Fertilizer Nitrogen: Influence of Sward Type, Pattern of Fertilizer Application and Method of Harvesting
12. Response to Fertilizer Nitrogen: Influence of Weather, Seasonal Factors and Soil Type
13. Response to Fertilizer Nitrogen: Influence of Type of Fertilizer and Supplies of Other Nutrients
14. Influence of Fertilizer Nitrogen on the Composition and Nutritional Quality of Grassland Herbage
15. Nitrogen Balances in Contrasting Grassland Systems