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Kinetics Of Phosphate Release In Tropical Soils
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Book Synopsis Kinetics of Phosphate Release in Tropical Soils by : Abdu Nafiu
Download or read book Kinetics of Phosphate Release in Tropical Soils written by Abdu Nafiu and published by LAP Lambert Academic Publishing. This book was released on 2010-12 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rate at which phosphate (P) is desorbed from the soil surface into soil solution is a key factor that regulates the continuous supply of P to crops. understanding the kinetics of P desorption is paramount for effective P management in order to boost agricultural production and to minimize environmental degradation and pollution. Several kinetic models were compared for describing P desorption rates in savanna soils of varying lithogenic origins, and the effect of soil properties on P release rate was determined. Phosphate desorption rates were best described by three empirical kinetic models: Elovich equation, the parabolic diffusion equation and the fractional power equation. The rate coefficients varied widely among soils from the same parent materials and between parent materials due probably to variations in the properties of the soils. This work is intended to give an inner understanding of P behavior and management strategies especially in tropical soils with variable charge properties and high preponderance of Fe and Al oxides, most especially to researchers and graduate students that are interested in chemical kinetics and phosphorus chemistry.
Book Synopsis Characterizing Phosphate Desorption Kinetics from Soil by : Abi Taddesse Mengesha
Download or read book Characterizing Phosphate Desorption Kinetics from Soil written by Abi Taddesse Mengesha and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Many agricultural fields that have received long-term applications of P often contain levels of P exceeding those required for optimal crop production. Knowledge of the effect of the P remaining in the soil (residual effect) is of great importance for fertilization management. In order to characterize P forms in soils, a wide variety of methods have been proposed. The use of dialysis membrane tubes filled with hydrous ferric oxide (DMT-HFO) has recently been reported as an effective way to characterize P desorption over a long-term in laboratoty studies. However, there is little information on the relationship between kinetics of P release using this new method and plant P uptake. This method consist of a procedure of shaking a sample for a long period of time there by exploiting the whole volume of the soil which is in contrast to the actual plant mode of uptake. This method has also practical limitations in employing it for a routine soil analysis, as it is very expensive and time consuming. The objectives of this study were (i) to study the changes in labile, non-labile and residual P using successive P desorption by DMT-HFO followed by a subsequent fractionation method (combined method) (ii) to assess how the information gained from P desorption kinetic data relates to plant growth at green house and field trials (iii) to investigate the effect of varying shaking time on DMT-HFO extractable P and (iv) to propose a short cut approach to the combined method. The release kinetics of the plots from long term fertilizer trials at the University of Pretoria and Ermelo were studied. P desorption kinetics were described relatively well by a two-component first-order model (R2 = 0.947, 0.918, & 0.993 for NPK, MNK, & MNPK treatments respectively). The relative contributions of both the labile pool (SPA) and the less labile pool (SPB) to the total P extracted increased with increased P supply levels. Significant correlations were observed between the rate coefficients and maize grain yield for both soil types. The correlation between the cumulative P extracted and maize yield (r = 0.997**) however was highly significant for Ermelo soils. This method was also used to determine the changes in the different P pools and to relate these P fractions with maize yield. Highly significant correlations were observed between maize grain yield and the different P fractions including total P. In both soil types the contribution of both the labile and non-labile inorganic P fractions in replenishing the solution Pi was significant where as the contributions from the organic fractions were limited. The C/HCl-Pi is the fraction that decreased most in both cases as well. Investigation was carried out to evaluate the effect of varying shaking periods on the extractable DMT-HFO-Pi for UP soils of varying P levels. Four shaking options were applied. Significant difference was observed for the treatment of high P application. Shaking option 2 seemed relatively better than the others since it showed the strongest correlation. Thus for soils with high releasing kinetics and high total P content, provided that the P release from the soil is a rate limiting step, reducing the length of shaking time could shorten the duration one needs to complete the experiment with out influencing the predicting capacity of the methodology. The other objective of this thesis was also to present a short cut method alternative to the combined fractionation method. Comparison of the sum of DMT-HFO-Pi, NaHCO3-Pi, NaOH-Pi, D/HCl-Pi and C/HCl-Pi extracted by a conventional step-by-step method with the sum of DMT-HFO-Pi and a single C/HCl-Pi extraction as a short cut approach for all extraction periods resulted in strong and significant correlations. The C/HCl-Pi fraction extracted by both methods was correlated with maize grain yield and it was found to be highly significant. This study revealed that this short cut approach could be a simplified and economically viable option to study the P dynamics of soils especially for soils where the P pool acting as a source in replenishing the labile portion of P is already identified. The method employed here therefore could act as an analytical tool to approximate successive cropping experiments carried out under green house or field condition. However, data from a wider range of soils is needed to evaluate the universality of this method. More work is also required in relating desorption indices of this method with yield parameters especially at field level.
Book Synopsis Phosphorus Biogeochemistry of Sub-Tropical Ecosystems by : K. Ramesh Reddy
Download or read book Phosphorus Biogeochemistry of Sub-Tropical Ecosystems written by K. Ramesh Reddy and published by CRC Press. This book was released on 1999-04-29 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus is one of the major nutrients limiting the productivity of terrestrial, wetland and aquatic ecosystems. Over the last decade several research projects were conducted on Florida's ecosystems from state and federal agencies and private industry to address water quality issues, and to develop management practices to control nutrient loads. Phosphorus Biogeochemistry in Sub-Tropical Ecosystems is the first thorough study of the role of phosphorus in ecological health and water quality ever published. Because of its vast and extensively studied ecosystems, Florida has often served as a national laboratory on current and future trends in ecosystem management. The reader will find studies at all levels of biological organization, from the cellular to entire ecological communities. The book is a definitive study of the role and behavior of phosphorus deposition in the upland/wetland/aquatic environment. The papers presented in this book are organized in specific groups: ecological analysis and global issues, biogeochemical transformations, biogeochemical responses, transport processes, phosphorus management, and synthesis. Although Florida's ecosystems are used as a case study, the results presented have global applications.
Book Synopsis Chemical Processes in Soils by : M. A. Tabatabai
Download or read book Chemical Processes in Soils written by M. A. Tabatabai and published by . This book was released on 2005 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Phosphate Desorption Characteristics of Some Tropical Soils by : S. J. McKean
Download or read book Phosphate Desorption Characteristics of Some Tropical Soils written by S. J. McKean and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Inorganic Contaminants in the Vadose Zone by : Bnayahu Bar-Yosef
Download or read book Inorganic Contaminants in the Vadose Zone written by Bnayahu Bar-Yosef and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The understanding of pollutant transformations, sorption and transport in soils and uptake by plants is the key to controlling contaminant movement towards groundwater and accumulation in food-chains. Some of these major processes were discussed in the first International Workshop on Pollutants in Porous Media, con vened in Israel in 1983 (pollutants in Porous Media, Eds. Yaron, Dagan and Goldshmid, Springer-Verlag, 1984). Since that meeting, research on contaminant impact on the environment expanded considerably. New mechanisms explaining inorganic pollutant par titioning between solid and solution phases in soils were proposed and tested; specific elements and specific reactions were investigat ed, and more case studies to evaluate management practice effects on drinking water quality and accumulation of contaminants in crops were carried out. The recognition that the new knowledge needs to be discussed and evaluated, and the scientific and engineering communities be updated, led the IUPAC (Interna tional Union of Pure and Applied Chemistry) and IAHS (Interna tional Association of Hydrological Sciences) Water Quality Com missions to organize a second International Workshop on pollu tant behaviour in the vadose zone, hosted by the Institute of Soils and Water of the Agricultural Research Organization, Israel. In this workshop, taking place in June 1987, attention was focused on chemical, physico-chemical and microbial-mediated reactions of different contaminants in the vadose zone. This book contains selected works presented in the 1987 workshop by invited special ists from various disciplines and countries.
Book Synopsis Inositol Phosphates by : Benjamin L. Turner
Download or read book Inositol Phosphates written by Benjamin L. Turner and published by CABI. This book was released on 2007 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inositol phosphates are a group of organic compounds found widely in the natural environment. They are important in agriculture because they constitute most of the phosphorus in grain seeds, but they cannot be digested by some animals. As a result, considerable research has been directed towards improving the digestibility of inositol phosphates in animal diets. Inositol phosphates are also abundant in soils and water bodies, yet a clear understanding of their behaviour in the environment remains elusive. This is surprising given the importance of phosphorus in the nutrition of both terrestrial and aquatic ecosystems. Written by leading experts, this book brings together critical reviews on inositol phosphates in agriculture, ecology, and the environment. The sixteen chapters cover a diverse range of topics, including the synthesis and hydrolysis of inositol phosphates, their role in animal nutrition, and their fate in soils and aquatic ecosystems. It will prove valuable to a wide readership in the agricultural and biological sciences, and will serve as a unique reference source on this emerging topic.
Book Synopsis Phosphate Release in Laboratory Soil Columns by : T. J. Bicki
Download or read book Phosphate Release in Laboratory Soil Columns written by T. J. Bicki and published by . This book was released on 1978 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Reactions with Variable-Charge Soils by : J. Barrow
Download or read book Reactions with Variable-Charge Soils written by J. Barrow and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Organic Phosphorus in the Environment by : Benjamin L. Turner
Download or read book Organic Phosphorus in the Environment written by Benjamin L. Turner and published by Cabi. This book was released on 2005 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus is essential for life, yet is often the element most limiting for biological productivity. Although most organisms take up phosphorus in an inorganic form, organic forms frequently dominate in soils and aquatic systems. Up to this point, the role of organic phosphorus and mechanisms for its dynamics have been poorly understood. However, recent advances in research have shed new light on the subject and this book brings together these advances. It covers the transformation and characterization of organic phosphorus in both terrestrial and aquatic systems. It will attract a broad range of scientists from several disciplines.
Download or read book Soil Phosphorus written by Rattan Lal and published by CRC Press. This book was released on 2016-09-19 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus is an essential plant nutrient, but global population growth has dramatically reduced the availability of phosphorus fertilizer resources. Despite this scarcity, there remain numerous problems associated with the excessive and inappropriate use of phosphorus leading to non-point source pollution and eutrophication of natural waters. Identifying appropriate systems for managing soil phosphorus and reducing the risks of eutrophication are needed to minimize the environmental risks. This book focuses on the availability and recycling of phosphorus; regulatory and policy issues of sustainable phosphorus use; and water quality management in agroecosystems pertaining to phosphorus. Sections are dedicated to global phosphorus reserves; cycling and pathways of phosphorus; phosphorus in agriculture; human dimensions and policy intervention; and research and development priorities. Phosphorus is a finite but crucial resource and is an essential element to all life. Sub-optimal availability and nutrient imbalance in the root zone can adversely impact plant growth, and the quality of food and feed grown on these soils. However, the proven reserves of phosphorus can hardly be adequate for a few centuries only. Yet, its misuse and mismanagement has caused severe problems of eutrophication of water and pollution of the environment. Thus, judicious management of soil phosphorus is essential. This volume is specifically devoted to availability and recycling of phosphorus, regulatory/policy issues of sustainable use of phosphorus, and management in agroecosystems in the context of maximizing the use efficiency and minimizing the environmental risks of water quality.
Download or read book Fertilizer Abstracts written by and published by . This book was released on 1972 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Soil Fertility Improvement and Integrated Nutrient Management by : Joann Whalen
Download or read book Soil Fertility Improvement and Integrated Nutrient Management written by Joann Whalen and published by BoD – Books on Demand. This book was released on 2012-02-24 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil Fertility Improvement and Integrated Nutrient Management: A Global Perspective presents 15 invited chapters written by leading soil fertility experts. The book is organized around three themes. The first theme is Soil Mapping and Soil Fertility Testing, describing spatial heterogeneity in soil nutrients within natural and managed ecosystems, as well as up-to-date soil testing methods and information on how soil fertility indicators respond to agricultural practices. The second theme, Organic and Inorganic Amendments for Soil Fertility Improvement, describes fertilizing materials that provide important amounts of essential nutrients for plants.The third theme, Integrated Nutrient Management Planning: Case Studies From Central Europe, South America, and Africa, highlights the principles of integrated nutrient management. Additionally, it gives case studies explaining how this approach has been implemented successfully across large geographic regions, and at local scales, to improve the productivity of staple crops and forages.
Book Synopsis Advances in Integrated Soil Fertility Management in sub-Saharan Africa: Challenges and Opportunities by : Andre Bationo
Download or read book Advances in Integrated Soil Fertility Management in sub-Saharan Africa: Challenges and Opportunities written by Andre Bationo and published by Springer Science & Business Media. This book was released on 2007-10-16 with total page 1051 pages. Available in PDF, EPUB and Kindle. Book excerpt: Food insecurity is a fundamental challenge to human welfare and economic growth in Africa. Low agricultural production leads to low incomes, poor nutrition, vulnerability to risk and threat and lack of empowerment. This book offers a comprehensive synthesis of agricultural research and development experiences from sub-Saharan Africa. The text highlights practical lessons from the sub-Saharan Africa region.
Download or read book Agrochimica written by and published by . This book was released on 2006 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Phosphate Release in Calcareous Soils with Elemental Sulfur by : Michael Robinson
Download or read book Phosphate Release in Calcareous Soils with Elemental Sulfur written by Michael Robinson and published by . This book was released on 1976 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Rock Phosphate Dissolution in Soils as Affected by Source of Rock, Soil Type, Method of Placement and Sulpher Addition by : Gadelkarim Mahoud Madibo
Download or read book Rock Phosphate Dissolution in Soils as Affected by Source of Rock, Soil Type, Method of Placement and Sulpher Addition written by Gadelkarim Mahoud Madibo and published by . This book was released on 1986 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
