Contents: 1. Primary Productivity. 2. Secondary Productivity. 3. Nutrient Cycling. 4. Systems Management.
Although ecologists have tended to regard agricultural ecosystems as unsuitable subjects for study, some of the most intensive studies of ecosystem processes have been made on agricultural ecosystems, and especially on grassland ecosystems. Agricultural ecosystems are generally simpler, and therefore easier to study than natural ecosystems, and the resulting studies have yielded a vast amount of information and many new research techniques have been developed. This volume, with its two main themes of energy flow and nutrient cycling in managed grasslands, is the first to treat these two subjects in an integrated way. Energy flow is considered mainly in the context of primary and secondary productivity, while nutrient cycling is considered especially in the context of fertilizer use. The result is not just a description of managed grassland ecosystems, but a bridging of the gap between ecological principles and agricultural practice. Ecologists will value the wealth of information, ideas and techniques that have resulted from managed grasslands studies - much of which is applicable to natural ecosystems. Agronomists will be interested in the ecological processes and principles underlying current management practices.
I. Primary Productivity. 1. General introduction (R.W. Snaydon). 2. The productivity of temperate grasslands (J.E. Radcliffe, J.A. Baars). 3. The productivity of mediterranean and semi-arid grasslands (E.F. Biddiscombe). 4. Physiological aspects of pasture growth (C. Marshall). 5. Modelling pasture growth (K.R. Christian). 6. Effects of nitrogen fertilizer (J. Morrison). 7. Effects of grazing and cutting (C.J. Korte, W. Harris). 8. The botanical composition of pastures (R.W. Snaydon). II. Secondary Productivity. 9. Beef production from managed grasslands (W. Holmes). 10. Milk production from managed grasslands (C.W. Holmes). 11. Sheep production from managed grasslands (P.V. Rattray). 12. Other domesticated animals (J.M. Walsingham). 13. Grazing behaviour (G.W. Arnold). 14. Plant factors affecting intake (D.J. Minson). 15. Minerals in pastures and supplements (D.I.H. Jones, T.A. Thomas). 16. Reproduction, lifespan and efficiency of production (J.M. Walsingham). III. Nutrient Cycling. 17. Nitrogen cycling in managed grasslands (M.J.S. Floate). 18. Phosphorus cycling in managed grasslands (A.G. Gillingham). 19. Return of nutrients by animals (N.J. Barrow). 20. Nitrogen fixation in managed grasslands (J.H. Hoglund, J.L. Brock). 21. Nitrogen losses from managed grassland (K.W. Steele). 22. Run-off and drainage from grassland catchments (F.X. Dunin). IV. Systems Management. 23. Economic considerations in the production and utilization of herbage (C.J. Doyle). 24. Stocking rate (D.H. White). 25. Fertilizer inputs and botanical composition (R.W. Snaydon). 26. Herbage conservation and supplements (H.A. Birrell). Glossary. Systematic List of Genera. Author Index. Systematic Index. General Index.