Download or read book Applications of Continuous and Steady State Methods to Root Biology written by John G. Torrey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an excellent illustration of the interrelationship between progress in scientific methodology and conceptual advances, and its publica tion should contribute to further advances. It is well known that major advances in understanding often follow the development of new methods. The development of the acetylene reduction assay for nitrogenase activity provides a good example of this interrelationship between theory and methods. Theoretical knowledge led to a search for substrates for nitro genase that could be assayed for more easily than ammonium, the normal product of the enzyme. The discovery of the reduction of acetylene to ethylene by nitrogenase provided the ideal answer to the problem by provid ing a rapid, specific, nondestructive, and inexpensive assay for nitrogenase activity. This assay is now used by almost every laboratory doing research on nitrogen fixation. However, further use and development of the acetylene reduction assay has shown that it can underestimate nitrogenase activity and can even give incorrect relative values under some circumstances. The major problem is that exposure of legume nodules to acetylene can cause a large increase in the resistance to oxygen diffusion into the nodule. This reduced supply of oxygen decreases the rate of nitrogenase activity within a few minutes.
Download or read book Symbiotic Nitrogen Fixation written by P. Graham and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past three decades there has been a large amount of research on biological nitrogen fixation, in part stimulated by increasing world prices of nitrogen-containing fertilizers and environmental concerns. In the last several years, research on plant--microbe interactions, and symbiotic and asymbiotic nitrogen fixation has become truly interdisciplinary in nature, stimulated to some degree by the use of modern genetic techniques. These methodologies have allowed us to make detailed analyses of plant and bacterial genes involved in symbiotic processes and to follow the growth and persistence of the root-nodule bacteria and free-living nitrogen-fixing bacteria in soils. Through the efforts of a large number of researchers we now have a better understanding of the ecology of rhizobia, environmental parameters affecting the infection and nodulation process, the nature of specificity, the biochemistry of host plants and microsymbionts, and chemical signalling between symbiotic partners. This volume gives a summary of current research efforts and knowledge in the field of biological nitrogen fixation. Since the research field is diverse in nature, this book presents a collection of papers in the major research area of physiology and metabolism, genetics, evolution, taxonomy, ecology, and international programs.
Download or read book Nutrient Uptake and Cycling in Forest Ecosystems written by L.O. Nilsson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the research results and discussions presented in this book it becomes clear that a profound understanding of the various interrelationships of the nutritional aspects allows the implementation of specific management strategies to improve stability and productivity of forest ecosystems. In particular the effects of environmental changes as related to the impacts of air pollution, global change and land use on nutrient uptake and cycling processes in forest ecosystems are dealt with in detail. The book is divided into six main issues and each topic contains reviews as well as selected results of recent studies.
Download or read book Current Issues in Symbiotic Nitrogen Fixation written by G.H. Elkan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 100 years since the legume-Rhizobium symbiotic nitrogen fixation interaction was first described, interest in this field has grown rapidly. The types of studies have been cyclical in nature, involving a cross-section of disciplines. The availability of cheap nitrogenous fertilizers caused much of the biological nitrogen fixation research to become more theoretical in the developed world. The high cost of energy, coupled with environmental concerns and the interest in sustainable agriculture, has stimulated research in symbiotic nitrogen fixation. The development of modern genetic techniques has resulted in interdisciplinary research on plant-microbe interactions controlling nitrogen fixation. This has resulted in a better understanding of environmental factors influencing the nodulation process, chemical signalling between the symbiotic partners and the nature of the specificity between host plant and microsymbiotant. This volume summarizes the diverse research efforts in biological nitrogen fixation by presenting a collection of papers in the areas of physiology and metabolism, taxonomy and evolution, genetics and ecology.
Download or read book Fertilizers and Environment written by Claudio Rodriguez Barrueco and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Food production remains the highest agricultural priority, subject to the constraint that it be done in harmony with nature, or at least with minimum environmental pollution. The amount of fertilizer applied can be controlled using modern application techniques, including soil and crop management, guaranteeing higher economic profit and lower environmental cost. It is in such a context that the present book addresses the efficient and rational use of mineral and organic fertilizers while preserving environmental quality. The book discusses the impact on surface and groundwaters, soils and crops, and experience of nitrate leaching, denitrification, ammonia volatilization, heavy metal pollution, agricultural and urban waste management, and international and national legislation. Audience: Agronomists, environmentalists, soil and food chemists, ecologists, policy makers, and managers in the fertilizer industry concerned with the trend of public opinion.
Download or read book Plant Nutrition from Genetic Engineering to Field Practice written by J. Barrow and published by Springer Science & Business Media. This book was released on 1993 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Twelfth International Plant Nutrition Colloquium, 21--26 September 1993, Perth, Western Australia
Download or read book Research Articles written by and published by Bib. Orton IICA / CATIE. This book was released on 2004 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aboriginal reconciliation -- Addictions -- Allergies -- Archeology --Alternative fuel for cars --Atomic bomb -- Australian animals -- Australian cultural icons -- Ballet -- Beetles -- Brand power -- Climbing mountains -- Computer animation-- Computer dating-- Convicts in exile -- Captain Cook's voyages-- Dairy production-- Dangerous predators-- Dogs -- Dumbing-down of society-- Ecological footprint -- Euthanasia-- Fast food-- Gambling-- Gay cowboy-- Genetic engineering -- Germs, viruses, epidemics --Global warming-- Hijab-- Horses-- Insomnia cure --Internet-- John Pilger-- Life savers-- Love-- Lunar and social eclipses-- Monster makers-- Nanotechnology -- National treasures -- Pirates -- Pope John Paul II -- Qantas 85th Anniversary -- Re-cycling -- Science fiction -- Space travel -- Sharks -- Sheep farming -- Spam -- Sun -- Text messaging -- Tunnels -- Venomous creatures -- Water -- Whaling -- Wizardry -- Women at war -- Seven wonders of the world -- World War 2.
Download or read book Isotopic Studies of Azolla and Nitrogen Fertilization of Rice written by K.S. Kumarasinghe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Genetic Aspects of Plant Mineral Nutrition written by P.J. Randall and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: The adaptation of desirable agricultural plants to infertile and problem soils is an increasingly important trategy for improving food supplies in many parts of the world. The plant breeding approach complements, and in some cases may replace agronomic practices such as the use of fertilizers and soil amendments to provide solutions which are economically and environmentally sustainable. The Symposium at which the papers in this volume were presented drew together workers in plant breeding, plant nutrition, physiology, biochemistry and molecular biology to discuss research on gene systems which affect the mineral nutrition of plants. Papers describe successes in plant breeding for problem soils as well as advances in understanding of mechanisms at the whole plant and cellular levels. Papers in the 'molecular' area point the way to the contribution which the new biology will make to this field in the future. The reviews and research papers are grouped under five topics : Better plants for acid soils; Salinity tolerance; Efficiency of uptake and use of macronutrients; Efficiency for iron and micronutrients; Tolerance of heavy metals and boron.
Download or read book Structural and Functional Aspects of Transport in Roots written by B.C. Loughman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Third International Symposium on `Structure and Function of Roots', NITRA, Czechoslovakia, August 3-7, 1987
Download or read book Progress in Nitrogen Cycling Studies written by O. van Cleemput and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the `8th Nitrogen Workshop' which was held at the University of Ghent, Belgium, from 5 to 8 September 1994. Although nitrogen dynamics in different ecosystems have been studied for several decades, new orientations and other emphases have recently emerged. Previously, nitrogen was considered as an essential element mostly in terms of productivity, but now, more emphasis is attached to environmental consequences. More than 100 contributions in this book tackle recent developments within the fields of nitrogen advice systems, plant response to fertilization, immobilization and mobilization, nitrification, denitrification, leaching, ammonia volatilization and biological nitrogen fixation. A large number of papers is devoted to the formation of gaseous nitrogen compounds, while mineralization-immobilization is another topic of important interest. The book also contains the reports of discussion groups on different aspects of the nitrogen cycle.
Download or read book Soil and Water Quality at Different Scales written by Peter A. Finke and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated studies on the assessment and improvement of soil and water quality have to deal almost inevitably with issues of scale, since the spatial support of measurements, the model calculations and the presentation of results usually vary. This book contains the selected and edited proceedings of a workshop devoted to issues of scale entitled: `Soil and Water Quality at Different Scales', which was held in 1996 in Wageningen. It is intended for environmental researchers, scientists and MSc and PhD students. Part 1 covers current issues and methodologies with scale related soil and water quality research. Part 2 covers agroecological and hydrological case studies in which scale transforms form an important part of the research chain. Part 3 consists of papers focusing on methodologies and up and downscaling. Part 4 contains review papers based on modellers' and statisticians' considerations as well as the papers and posters presented during the workshop. Part 5 consists of short research notes.
Download or read book Nitrogen Economy in Tropical Soils written by N. Ahmad and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Nitrogen Turnover in the Soil Crop System written by J.J. Groot and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Netherlands the Institute for Soil Fertility Research plays a major role in soil biological, soil physical and plant nutritional research on the availability of nitrogen to crops. Main subjects of research are nitrogen turnover in the crop-soil ecosystem through biological transformations, nitrogen transport through the soil and nitrogen losses by leaching, denitrification and volatilization, and nitrogen use efficiency of various crops and cropping systems. The current knowledge in the different fields of research is integrated in simulation models. Simulation models not only make it possible to summarize and structure knowledge, but also, after verification, to extra- late the knowledge to situations different from the situations that have actually been studied. Such research is also carried out in other European and non-European countries. To compare the various simulation models currently in use, a workshop was organized by the Institute for Soil Fertility Research on 5-6 June 1990 on the occasion of its centennial. The title of the workshop was 'Nitrogen turnover in the soil-crop ::cosystem: modelling of biological transformations, transport of nitrogen and nitrogen use efficiency'. The 40 Jarticipants, who came from Canada and various European countries, were requested to run their model with data Jrovided by the Institute prior to the workshop. Data from 18 cases were made available to the participants: three ocations, three treatments, and two seasons.
Download or read book Iron Nutrition and Interactions in Plants written by Y. Chen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many agricultural crops worldwide, especially in semi-arid climates, suffer from iron deficiencies. Among plants sensitive to iron deficiency are apples, avocado, bananas, barley, beans, citrus, cotton, grapes, peanuts, pecans, potatoes, sorghum, soybeans, and numerous ornamental plants. Deficiencies are usually recognized by chlorotic, in new leaves and are typically found among sensitive crops grown in calcareous or yellowed, interveinal areas soils which cover over 30% of the earth's land surface. Iron deficiency may lead, in extreme cases, to complete crop failure. In intensive agriculture on calcareous soils, iron often becomes a major limiting nutrient for optimal crop production, thus, correction of iron deficiency is required. Various chemicals and practices are available. They are, however, costly and do not always result in a complete remedy of the deficiency. Crucial questions relative to the cost-benefit equation such as the recovery rate of plants and the long-term fertilizing effect have not yet been resolved. The complexity of iron nutrition problems requires an understanding of the chemistry of iron oxides in soils, of the chemistry of both natural and synthetic chelates, of rhizosphere microbiology and biochemistry, and of the physiological involvement of the plant in iron uptake and transport.
Download or read book Alleviating Soil Fertility Constraints to Increased Crop Production in West Africa written by A. Uzo Mokwunye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tropical Africa escaped from the glaciers that covered the temperate parts of the world during the Ice Age. The legacy is that most of the parent materials of the soils of tropical Africa are old, highly weathered and devoid of bases and phosphate-bearing minerals. Traditional farming systems which were relatively stable and sustainable relied on long fallow periods after one to two years of cropping to maintain the productive capacity of the soils. In recent times and especially in densely populated areas, a sizeable class of 'landless' farmers have begun to cultivate marginal lands or to invade the 'forest reserves' thereby exacerbating the problems of land and environ mental degradation. of soil fertility that will facilitate the production of adequate quantities of the principle Maintaining a level staples has become a major challenge to agricultural scientists in tropical Africa. To increase the nutrient supplying power of soils requires the inputs of fertilizers. These can be organic or inorganic. The efficiency with which these externally supplied inputs can increase agricultural production and reduce soil and environmental deterioration is dependent on the ability of scientists to determine the right types and quantities of the products to apply to each soil, crop and cropping system as well as the ability of farmers to acquire requisite farm manage ment skills.
Download or read book Plant Soil Interactions at Low pH written by Robert J. Wright and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1057 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil acidity is a major limitation to crop production in many parts of the world. Plant growth inhibition results from a combination of factors, including aluminum, manganese, and hydrogen ion toxicities and deficiencies of essential elements, particularly calcium, magnesium, phosphorus, and molybdenum. Agricultural management practices and acid precipitation have increased acid inputs into the ecosystem and heightened concern about soil acidity problems. While application of lime has proved to be effective in ameliorating surface soil acidity in many areas, significant soil acidity problems still exist. Scientists from Alberta, Canada, recognized the need to provide a forum for researchers from different disciplines to exchange information and ideas on solving problems of plant growth in acid soils. As a result of their efforts, the First International Symposium on Plant-Soil Interactions at Low pH was held at Grande Prairie, Alberta, Canada, in July 1987. In many acid soil areas, liming materials are not readily available, the cost may be prohibitive, or subsoil acidity cannot be corrected by surface application of lime. New management approaches involving both the plant and the soil are needed in these situations. Progress has been made in the selection and breeding of acid-tolerant plants. However, continued progress will be limited by our lack of understanding of the physiological and biochemical basis of differential acidity tolerance among plants.
