Author: K.S. Kumarasinghe
Publisher: Springer Science & Business Media
ISBN: 9401116814
Category : Technology & Engineering
Languages : en
Pages : 156
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Book Description
Nitrogen is the most limiting element for crop production. Traditionally, expensive commercial fertilizers are used to correct soil nitrogen deficiencies. Indeed, 50% of the increase in rice yields after World War II can be attributed to increased fertilizer nitrogen use. Although an increased rate of fertilizer nitrogen application has been advocated to meet the growing demand for food, it is unrealistic to advise the farmers to apply fertilizers they could hardly afford, and whose prices are likely to escalate in the years ahead. In addition, when they are not applied judiciously there are problems of environmental pollution as plants are capable of taking up only a relatively small portion of the applied nitrogen, a substantial amount being lost through various chemical and biological processes. The exploitation of cheaper alternatives or supplements to fertilizers have therefore gained much interest in recent years. Our increased interest in biological nitrogen fixation as a supplement or alternative to nitrogen fertilizers led to the convening of a consultants' meeting on `The Role of Isotopes in Studies on Nitrogen Fixation and Nitrogen Cycling by Blue-Green Algae and the Azolla-Anabaena azollae Association', in Vienna from 11--15 October 1982. The consultants' group recommended that the Joint FAI/IAEA Division of Nuclear Techniques in Food and Agriculture embark on a coordinated research programme in this field and that initial emphasis should be placed on Azolla-Anabaena symbiosis. As a result, such a programme was initiated in 1984, which was concluded in 1989. The results and conclusions reported here are those that were generated during the five years of its operation.
Author: Junoo Kamal Tuladhar
Publisher: Cuvillier Verlag
ISBN: 3898739740
Category : Science
Languages : en
Pages : 130
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Book Description
The low productivity of the rice-wheat cropping system in Nepal is associated with a low efficiency of applied mineral N in rice. The aquatic fern Azolla was used to reduce N losses via ammonia volatilization from the flooded lowland rice in farmers' field conditions in Nepal. The Azolla cover changed the floodwater chemistry, thus reducing ammonia volatilization losses. The use of Azolla in combination with Urea increased rice yields by 15% and reduced urea-N losses from 17-38% to 2-8%. A combined use of Azolla and urea is a viable option to enhance the productivity of rice-wheat systems in Nepal.
Author: N. Ahmad
Publisher: Springer Science & Business Media
ISBN: 9400917066
Category : Science
Languages : en
Pages : 430
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Book Description
Nitrogen Economy in Tropical Soils presents an authoritative and comprehensive state-of-the-art review on soil/plant nitrogen inter-relationships, with special reference to tropical soils and crops in aerobic and anaerobic environments. Use of isotopically labelled nitrogen in experimentation, especially in tropical environments, and recently developed analytical techniques for soil and plant materials are presented. An important aspect is the emphasis placed on the impact of the tropical environment on nitrogen transformations in the soil environment. This book should be an excellent source of information for senior undergraduate and graduate students with interest in soil/plant nitrogen inter-relationships, and for all levels of research workers in these fields.
Author: Raoul Dudal
Publisher: Food & Agriculture Org.
ISBN: 9789251036655
Category : Science
Languages : en
Pages : 440
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Book Description
This publication is structured on the main themes of the consultation: the importance of plant nutrition for meeting agricultural product requirements; soil organic matter, biomass, soil microflora and management of integrated plant nutrition systems; renewable supply of plant nutrients from natural sources and plant nutrient transfer to crops; the place and role of local and external sources of plant nutrients in cropping systems and their evaluation; plant nutrient management in farming systems and in watersheds and territories; and priorities for FAO's Integrated Plant Nutrion Systems (IPNS) programme
Author: Springer
Publisher: Int. Rice Res. Inst.
ISBN: 0792367650
Category : Nature
Languages : en
Pages : 379
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Book Description
Author: K.A. Malik
Publisher: Springer Science & Business Media
ISBN: 9401152322
Category : Science
Languages : en
Pages : 349
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Book Description
Diazotrophic bacteria convert atmospheric nitrogen to plant-useable form and this input of nitrogen through biological fixation is of great agronomic importance. The contributions presented in this volume relate to free-living nitrogen fixers and the diazotrophs associated with plants. Symbiotic association of Frankia with non-legumes and cyanobacterial associations are also discussed. Research topics covered in this volume include the biochemistry and genetics of diazotrophs, recent developments in improvement of plant-microbe interactions and their molecular basis, the use of molecular probes in taxonomy and ecology of diazotrophs and reports on field applications, agronomic importance and improvement in methodologies for assessing their contribution to plants. This book provides valuable information not only for researchers working in the field of biological nitrogen fixation but also for biochemistry, molecular biologists, microbiologists and agronomists.
Author: Ken E. Giller
Publisher: CABI
ISBN: 0851994172
Category : Science
Languages : en
Pages : 441
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Book Description
The second edition of this book, first published in 1991 and intended for students and researchers, contains revised and updated material on the theory and practice of nitrogen fixation in tropical cropping systems. There are 15 chapters in 3 parts. Part I, Introduction, contains 5 chapters on tropical environments (climate, soils and cropping systems), nitrogen fixing organisms, the process of nitrogen fixation, assessment of the role of nitrogen fixation, and cycling of nitrogen in tropical cropping systems. Part II, Tropical crops and cropping systems, comprises 7 chapters on freeliving, root-associated and endophytic nitrogen fixing bacteria of cereal crops and grasses, cyanobacteria and Azolla as green manure for wetland rice, grain legumes, legumes as green manures and cover crops, forage legumes, understorey legumes and shade trees in plantation crops, and nitrogen fixing trees in agroforestry. Part III, optimizing nitrogen fixation, includes 3 chapters on environmental constraints, approaches to enhancement, and future impacts on nitrogen fixation in tropical agriculture. A list of common names and subject index are included.
Author: Reiner Wassmann
Publisher: Springer Science & Business Media
ISBN: 9401008981
Category : Science
Languages : en
Pages : 391
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Book Description
Rice production is affected by changing climate conditions and has the dual role of contributing to global warming through emissions of the greenhouse gas methane. Climate change has been recognized as a major threat to the global environment. Because of insufficient field data, rice-growing countries face a problem when trying to comply with the United Nations Framework Convention on Climate Change stipulations to compile a national inventory of emissions and to explore mitigation options. Given the expected doubling in rice production in Asia, the need to evaluate the interaction between climate change and rice production is critical to forming a sound basis for future directions of technology developments by policy makers, agriculturists, environmentalists, rice producers, and rice consumers. The present book comprises two sections. The first part documents a comprehensive overview of the results achieved from an interregional research effort to quantify methane emission from major rice ecosystems and to identify efficient mitigation options. This research report broadens understanding of the contribution of rice cultivation to methane emissions and clarifies that emissions are relatively low, except in specific rice ecosystems, and that these high emissions could be ameliorated without sacrificing yield. The second section shows results from other projects that investigated the role of rice cultivators in field and laboratory approaches. The findings represent inputs for future modeling approaches in the role of rice cultivators. The expanded database generated by other projects is reflected in modeling efforts.
Author: J.K. Ladha
Publisher: Int. Rice Res. Inst.
ISBN: 0792334132
Category : Nature
Languages : en
Pages : 300
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Book Description
Reprinted from Plant and Soil, v.174, nos.1-2 (1995), this volume is devoted to discussions on the role of biological nitrogen fixation (BNF) in agricultural sustainability. Papers presented on BNF in crop forage and tree legumes are augmented with discussion of integrated farming systems involving BNF, soil and N management, and recycling of legume residues. BNF by non-legumes is discussed and attempts to transform cereals into nodulating plants are critically reviewed. Also described are advances in the development of new methodologies to understand symbiotic interactions and to assess N-2 fixation in the field; means of enhancing BNF through plant and soil management; breeding and selection; problems encountered in exploiting BNF under farmers' field conditions; and promising approaches to improve BNF exploitation. Lacks a subject index. Annotation copyright by Book News, Inc., Portland, OR
Author: Rattan Lal
Publisher: CRC Press
ISBN: 1482245345
Category : Nature
Languages : en
Pages : 418
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Book Description
Faced with challenges of resource scarcity and environmental degradation, it is important to adopt innovative farming systems that maximize resource efficiency while protecting the environment. Soil-Specific Farming: Precision Agriculture focuses on principles and applications of soil-specific farming, providing information on rapidly evolving agri
