Nitrogen Economy in Tropical Soils

1. Forms and Nature of Organic N in Soil; K.R. Kelley, F.J. Stevenson. 2. Seasonal Fluctuations of Native Available N and Soil Management Implications; M.T.F. Wong, S. Nortcliff. Effect of Cultivation on the Nitrogen Fertility of Selected Agro-ecosystems in South Africa; C.C. du Preez, M.E. du Toit. 4. Assessment of Biological Nitrogen Fixation; S.K.A. Danso. 5. High Productivity Analysis of 15N and 13C in Soil/Plant Research; A. Barrie, et al. 6. Adapting the Potentially Mineralizable N Concept for the Prediction of Fertilizer N Requirements; C.A. Campbell, et al. 7. Field Application of the 15N Isotope Dilution Technique for the Reliable Quantification of Plant-Associated Biological Nitrogen Fixation; R.M. Boddey, et al. 8. Rational Nitrogen Fertilization in Intensive Cropping Systems; C.W. Rice, et al. Nitrogen Assimilation by Legumes - Processes and Ecological Limitations; S. Schubert. 10. Fate of CO(NH2)2-15N Applied to Taro (Colocasia esculenta var. esculenta) in an Acid Vertisol of Trinidad; N. Ramnanan, et al. 11. Brown Leaf Spot Disease and Fertilizer Interaction in Irrigated Rice Growing on Different Soil Types; R.H. Phelps, C.R. Shand. 12. Use of 15N For Fertilizer N Recovery and N Mineralization Studies in Semi-Arid Kenya; C.J. Pilbeam, G.P. Warren. 13. Significance of Timing and Method of N Fertilizer Application for the N-Use Efficiency in Flooded Tropical Rice; H.F. Schnier. 14. A Conceptual Assessment of the Importance of Denitrification as a Source of Soil Nitrogen Loss in Tropical Agro-Ecosystems;P.M. Groffman. 15. Soil, Plant and Atmospheric Conditions as they Relate to Ammonia Volatilization; R.R. Sharpe, L.A. Harper. 16. Nitrous Oxide (N2O) Emissions from Soils in Warm Climates; T. Granli, O.C. Bøckman. 17. The Role of Azolla in Curbing Ammonia Volatilization from Flooded Rice Systems; P.L.G. Vlek, et al. 18. Downward Movement of Nitrate and Ammonium Nitrogen in a Flatland Ultisol; F.M. Deare, et al. 19. 15N Isotope Dilution Techniques to Study Soil Nitrogen Transformations and Plant Uptake; D. Barraclough. 20. Nitrogen Transformations in Wetland Rice Ecosystems; S.K. de Datta. 21. Urea-N uptake by Dasheen (Colocasia esculenta L. Schott) in Relation to the Fertilizer Placement Method; G.A. Gouveia, et al. 22. Nitrogen Fixation by Trees in Relation to Soil Nitrogen Economy; Y.R. Dommergues. 23. Extension of Symbiotic Biological Nitrogen Fixation Technology in Developing Countries; D.H. Hubbell. 24. Nitrogen Fixation Associated with Grasses and Cereals: Recent Progress and Perspectives for the Future; R.M. Boddey, J. Dobereiner. 25. Recent Developments on the Use of Urease Inhibitors in the Tropics; B.H. Byrnes, J.R. Freney. 26. Biological N2-Fixation and Its Management in Wetland Rice Cultivation; P.A. Roger. 27. Managing Nitrogen for Sustainable Crop Production; C.A. Campbell, et al. 28. Searching for Criteria for the Selection of Efficient Tree Species for Fallow Improvement, with Special Reference to Carbon and Nitrogen; G. Schroth, et al. 29. Nitrogen Balance and Root