Nitrogen Economy in Tropical Soils: Proceedings of the International Symposium on Nitrogen Economy in Tropical Soils, held in Trinidad, W.I., January 9–14, 1994

Front Matter....Pages i-x
Forms and nature of organic N in soil....Pages 1-11
Seasonal fluctuations of native available N and soil management implications....Pages 13-26
Effect of cultivation on the nitrogen fertility of selected agro-ecosystems in South Africa....Pages 27-32
Assessment of biological nitrogen fixation....Pages 33-41
High productivity analysis of 15 N and 13 C in soil/plant research....Pages 43-59
Adapting the potentially mineralizable N concept for the prediction of fertilizer N requirements....Pages 61-75
Field application of the 15 N isotope dilution technique for the reliable quantification of plant-associated biological nitrogen fixation....Pages 77-87
Rational nitrogen fertilization in intensive cropping systems....Pages 89-97
Nitrogen assimilation by legumes — processes and ecological limitations....Pages 99-107
Fate of CO(NH 2 ) 2 - 15 N applied to taro ( Colocasia esculenta var. esculenta ) in an acid Vertisol of Trinidad....Pages 109-115
Brown leaf spot disease and fertilizer interaction in irrigated rice growing on different soil types....Pages 117-121
Use of 15 N for fertilizer N recovery and N mineralization studies in semi-arid Kenya....Pages 123-128
Significance of timing and method of N fertilizer application for the N-use efficiency in flooded tropical rice....Pages 129-138
A conceptual assessment of the importance of denitrification as a source of soil nitrogen loss in tropical agro-ecosystems....Pages 139-148
Soil, plant and atmospheric conditions as they relate to ammonia volatilization....Pages 149-158
Nitrous oxide (N 2 O) emissions from soils in warm climates....Pages 159-163
The role of Azolla in curbing ammonia volatilization from flooded rice systems....Pages 165-174
Downward movement of nitrate and ammonium nitrogen in a flatland ultisol....Pages 175-184
 15 N isotope dilution techniques to study soil nitrogen transformations and plant uptake....Pages 185-192
Nitrogen transformations in wetland rice ecosystems....Pages 193-203
Urea-N uptake by dasheen (Colocasia esculenta L. Schott) in relation to the fertilizer placement method....Pages 205-214
Nitrogen fixation by trees in relation to soil nitrogen economy....Pages 215-230
Extension of symbiotic biological nitrogen fixation technology in developing countries....Pages 231-239
Nitrogen fixation associated with grasses and cereals: Recent progress and perspectives for the future....Pages 241-250
Recent developments on the use of urease inhibitors in the tropics....Pages 251-259
Biological N 2 -fixation and its management in wetland rice cultivation....Pages 261-276
Managing nitrogen for sustainable crop production....Pages 277-296
Searching for criteria for the selection of efficient tree species for fallow improvement, with special reference to carbon and nitrogen....Pages 297-314
Nitrogen balance and root behavior in four pigeonpea-based intercropping systems....Pages 315-319
Recent research on problems in the use of urea as a nitrogen fertilizer....Pages 321-329
Nitrate contamination of groundwater: Measurement and prediction....Pages 331-338
Alternatives for nitrogen nutrition of crops in tropical agriculture....Pages 338-346
Behaviour of urea and ammonium sulfate fertilizers and their N uptake relationships in calcareous soils....Pages 347-353
Simple field testing sites to determine the extent of nitrogen leaching from agricultural areas....Pages 355-361
Comparison of legumes and fertilizer nitrogen for wheat production in subtropical Australia....Pages 363-369
Long-term N-fertilization calibration experiments — environmental aspects....Pages 371-377
Nitrification inhibitors, with emphasis on natural products, and the persistence of fertilizer nitrogen in the soil....Pages 379-388
Land use related nitrogen and global change....Pages 389-398
Response of sugarcane to nitrogen fertilization practices on some sugarcane soils in Trinidad....Pages 399-413
FAO/IAEA International networking in soil/plant nitrogen research....Pages 415-425
Nitrogen losses by leaching and runoff: methods and conclusions....Pages 427-432
Optimizing non-symbiotic nitrogen fixation in an acid Vertisol....Pages 433-437
Back Matter....Pages 439-442