Download or read book Nitrogen Mineralization and Denitrification in Histosols written by Thomas Flagstad Guthrie and published by . This book was released on 1976 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrogen in Agricultural Systems written by James Stuart Schepers and published by ASA-CSSA-SSSA. This book was released on 2008 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: Review of the principles and management implications related to nitrogen in the soil-plant-water system.
Download or read book Ecosystem Organization of a Complex Landscape written by Otto Fränzle and published by Springer Science & Business Media. This book was released on 2008-06-24 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is an essential text for scientists from a huge variety of disciplines, from ecologists to geographers and soil scientists. It provides a synthesis of long-term ecological analyses in the Bornhöved Lake District of northern Germany. The emphasis is on the comprehensive assessment of matter and energy fluxes. These operate in and between the terrestrial and aquatic ecosystems on the one hand, and on transdisciplinary landscape planning approaches on the other.
Download or read book Estimating Nitrogen Mineralization Potential of Soils and the Effect of Water and Temperature and Crop Residues on Nitrogen Net Mineralization written by Amabelia Silvia del Pino Machado and published by Cuvillier Verlag. This book was released on 2005-02-15 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical and physical procedures were tested to forecast soil net N mineralization in a group of eight soils of Lower Saxony, varying in pedological characteristics as well as management. Most of the indexes tested were well related to N mineralization obtained through incubation under controlled conditions, being less related to the N uptake by crops, probably because this parameter was limited by differences among crops. Factors affecting N mineralization were studied in soils of Uruguay through incubation, assessing simultaneously soil microbial activity through CO2 evolution. To evaluate the influence of the amount and quality of plant residues the effect of wheat straw (WS) and N addition was tested. The WS rate determined the extent of N immobilization, which was very fast. Mineral N availability influenced the remineralization of immobilized N, being higher in N depleted soils. There was a negative effect of fertilizer N addition on soil biomass, partially counteracted by WS amendment. This effect could be caused by the pH decrease and increased salt concentration of the soil solution. The next study compared decomposition patterns of different plant materials, crop residues and green manures. Chemical composition of plant materials influenced the pace of the decomposition process. No single chemical component could explain differences in decomposition patterns. The soluble C content was responsible for the initial decomposition flush, later cellulose and hemicellulose determined in a greater extent the decomposition pace. The phenolic compounds were negative along the whole incubation. Plant materials with low N concentrations at low N levels did not show differences in decomposition patterns, despite differences in composition. Although N concentration of residues did not affect decomposition pace, was the most important characteristic explaining net N mineralization. The influence of temperature on soil organic matter (SOM) mineralization followed an exponential model in the range from 5 to 40ºC. The calculated Q10 values, for both N and C mineralization, indicate a slightly more than two fold mineralization rate increase per each 10ºC increase in the two studied soils, despite differences in texture and SOM. There was a direct relationship between C and N mineralization and gravimetric soil water content, although the two studied soils showed differences in the response to changes in water content. Substantial microbial activity was observed at high water tensions, indicating that in dry periods mineral N is likely to accumulate in the soil.
Download or read book Mineral Nitrogen In The Plant Soil System written by R Haynes and published by Elsevier. This book was released on 2012-12-02 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mineral Nitrogen in the Plant-Soil System provides integrated accounts of the transformations and fate of mineral nitrogen in the plant-soil system. This book emphasizes the understanding of various processes and the factors that affect these processes. It also focuses on the role of biological nitrogen fixation in nitrogen cycling in natural and agricultural systems. The book is divided into seven major chapters and each chapter is further subdivided into various subtopics. The first chapter introduces and outlines the origin, distribution, and cycling of nitrogen in natural and agricultural terrestrial ecosystems. Chapter 2 focuses on the processes of decomposition and mineralization-immobilization turnover. The processes of nitrification are discussed in detail in Chapter 3. The following four chapters discuss topics of retention and movement of nitrogen in soils; gaseous losses of nitrogen; uptake and assimilation of mineral nitrogen by plants; and lastly, the use of nitrogen in agronomic practice. The book will be invaluable to graduate students and researchers in the field of agriculture. This will also cater other parties interested, such as agronomists, soil scientists, plant physiologists, horticulturists, and foresters.
Download or read book Soil Nitrogen Cycle written by Water Resources Scientific Information Center and published by . This book was released on 1972 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Organic Matter in Modern Agriculture written by Y. Chen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of organic residues as a means of maintaining and increasing soil fertility is of long-standing. This tradition has been somewhat neglected since the introduc tion of mineral fertilizers at low cost. More and more farmers and scientists are now showing renewed interest in the proper and effective use of org~tnic residues, composts and other recycled organic additives. The role and function of organic amendments in modern agricultural systems have become topics of major interest in the scientific and agricultural communities. Research work on residue disposal has provided new concepts on the interaction between organic components and soils as well as new handling technologies (e. g. pelletizing of organic residues). The trend to conserve energy has led scientists to study the minimal tillage system, to find ways of replacing conventional inorganic fertilizers with natural organic prod ucts or microbial preparations, and to develop new composting methods. The drive to achieve higher yields in commercial greenhouse farming has led to a search for optimum substrates as growth media and for improved management techniques. This has led to the introduction of organic substitutes for peat, nota bly those originating from agricultural wastes. Another important aspect is the current interest in organic farming, where use of synthetic chemicals is avoided or prohibited. An increasing percentage of the population in highly developed countries is willing to pay premium prices for food produced on soils where inorganic fertilizers and other agricultural chemicals have not been used.
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 Gaseous Loss of Nitrogen from Plant Soil Systems written by J.R. Freney and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: A growing interest has been shown recently in the dymanics of nitrogen in agricultural and natural ecosystems. This has been caused by increasing demands for food and fibre by a rapidly expanding world population, and by a growing concern that increased land clearing, cultivation and use of both fertilizer and biologically fixed nitrogen can have detrimental effects on the environment. These include effects on water quality, eutrophication of surface waters and changes in atmospheric composition all caused by increased cycling of nitrogenous compounds. The input and availability of nitrogen frequently affects the productivity of farming systems more than any other single management factor, but often the nitrogen is used inefficiently. Much of the fertilizer nitrogen applied to the soil is not utilised by the crop: it is lost either in solution form, by leaching of nitrate, or in gaseous forms as ammonia, nitrous oxide, nitric oxide or dinitrogen. The leached nitrate can contaminate rivers and ground waters, while the emitted ammonia can contaminate surface waters or combine with atmospheric sulfur dioxide to form aerosols which affect visibility, health and climate. There is also concern that increased evolution of nitrous oxide will deplete the protective ozone layer of the stratosphere. The possibility of a link between the intensity of agricultural use of nitrogen, nitrous oxide emissions and amounts of stratospheric ozone has focussed attention on these interactions.
Download or read book Soil Nitrogen written by William Victor Bartholomew and published by . This book was released on 1965 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: Origin and distribution of nitrogen in soil. Soil inorganic nitrogen. Organic nitrogen in soils. Ammonium fixation and other reactions involving a nonenzymatic immobilization of mineral nitrogen in soil. Mineralization and immobilization of nitrogen in the decomposition of plant and animal residues. Nitrification. Denitrification. Symbiotic nitrogen fixation. Environmental factors in the fixation of nitrogen by the legume. Nonsymbiotic nitrogen fixation. The plant's need for and use of nitrogen. Movement of nitrogen in soil. Evaluation of incoming and outgoing processes thar affect soil nitrogen.
Download or read book Fate and Transport of Nutrients written by Ronald F. Follett and published by . This book was released on 1995 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPA 600 2 written by and published by . This book was released on 1980 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soil Plant Nitrogen Relationships written by Donald R. Nielsen and published by Elsevier. This book was released on 2013-09-03 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen in the Environment, Volume 2: Soil-Plant-Nitrogen Relationships is the second of a two-volume treatise based on manuscripts presented at the international conference on ""Nitrogen in the Environment,"" held at the University of California Conference Center, Lake Arrowhead, in February, 1977. All original manuscripts were revised in accordance with discussions at the conference. The chapters published in these volumes are those revised manuscripts, with provisions in each chapter to preserve the major suggestions for their improvement. These two volumes—Nitrogen Behavior in Field Soil and Soil-Plant-Nitrogen Relationships—should be of value in bringing into perspective current knowledge on selected aspects of nitrogen in the environment. The book contains 22 chapters and opens with a study on the factors influencing nitrate acquisition by plants; assimilation and fate of reduced nitrogen. Separate chapters follow on topics such as absorption and utilization of ammonium nitrogen by plants; potential nitrate levels in edible plant parts; control of biological nitrogen fixation; and methods for analysis of denitrification in soils.
Download or read book Nitrogen Behavior in Field Soil written by Donald R. Nielsen and published by Elsevier. This book was released on 2013-10-22 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen in the Environment, Volume 1: Nitrogen Behavior in Field Soil is the first of a two-volume treatise based on manuscripts presented at the international conference on ""Nitrogen in the Environment,"" held at the University of California Conference Center, Lake Arrowhead, in February, 1977. All original manuscripts were revised in accordance with discussions at the conference. The chapters published in these volumes are those revised manuscripts, with provisions in each chapter to preserve the major suggestions for their improvement. These two volumes—Nitrogen Behavior in Field Soil and Soil-Plant-Nitrogen Relationships—should be of value in bringing into perspective current knowledge on selected aspects of nitrogen in the environment. This book contains 26 chapters and begins with a paper on field trials with isotopically labeled nitrogen fertilizer. Separate chapters follow on topics such as computer simulation modeling for nitrogen in irrigated croplands; spatial variability of nitrogen in soils; application of gaseous-diffusion theory to measure denitrification; and measurement and prediction of anaerobiosis in soils.
Download or read book Soil N Mineralization as Affected by Abiotic Factors and Tillage Systems written by Eileen Joyce Kladivko and published by . This book was released on 1982 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Immobilization and Mineralization of Nitrogen in Pasture Soil written by Johannes Ludovicus Maurice Huntjens and published by . This book was released on 1972-01-01 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
