Download or read book The Role of Free Iron Oxides in the Retention of Phosphorus in Some Highly Weathered Soils of the Tropics written by Kingston W. Nyamapfene and published by . This book was released on 1979 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Role of Fe oxides for Predicting Phosphorus Sorption in Calcareous Soils written by Mehruinsa Memon and published by . This book was released on 2008 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transformation of Inorganic Phosphorus Under Continuous Flooded Conditions and Wet dry Cycles and the Phosphorus Sorption desorption Characteristics of Two Acid Sulfate Soils written by Daud Bin Chinta and published by . This book was released on 1981 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mineralogical Aspects of Reactivity to Phosphorus Among Highly Weathered Soils written by Peter Adams and published by . This book was released on 1977 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Iron Oxyhydroxides in Phosphorus Chemistry of Some East Texas Forest Soils written by Amir Hass and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Forest soil phosphorus (P) chemical behavior was evaluated in some mid-rotation fertilized loblolly pine (Pinus taeda L.) plantations in East Texas, that differed in their site drainage characteristics. Forest floor mass and carbon content in the forest floor were determined. Total P (PT) in the forest floor, and total and Mehlich-1 P and citrate dithionite (CD) and acid ammonium-oxalate (AAO) extractable P, Al, Fe, and Mn within the mineral soil upper 100 cm were determined. Colorimetric determination of AAO and CD-extractable P by the molybdenum blue ascorbic acid method, without the use of pre-digestion, was assessed by an automated continuous flow injection system. Phosphorus distribution between different operationally defined solid phases and its relationships with CD and AAO extractable Mn, Al, Fe among depth, site, drainage class and treatment were evaluated. Soil P forms were highly correlated with iron oxides across sites, drainage classes, treatments, and depth intervals with significant differences in P content and distribution in the soil profile and solid phases among drainage classes. Soil P distribution patterns differed among drainage classes, yet it followed the distribution of the iron oxides. Iron oxide's role as a sink for soil P was higher in the well-drained compared to the poorly drained sites. Amorphous phases of iron oxides were higher in the poorly drained sites and dominated the role of iron oxides as a sink for P under the poor drainage conditions. Fertilization resulted in significantly higher forest floor mass, P content in the forest floor, and total P (PT) and CD-extractable P (Pd) in the soils' upper 10 cm. The treatment effect on P in the forest floor, and on PT and Pd in the upper 10 cm of the mineral soil was equivalent to 6, 19, and 11% of the applied P, respectively. AAO-extractable P was highly correlated with Mehlich-1 P in the fertilized plots. Treatment and site drainage class effects on P accumulation in the different solid phases in the mineral soil and in the forest floor and the potential contribution of these pools to P availability in subsequent rotations, following clearcutting, are discussed.
Download or read book Properties and Management of Soils in the Tropics written by Pedro A. Sanchez and published by Cambridge University Press. This book was released on 2019-01-10 with total page 685 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-awaited second edition of classic textbook, brought completely up to date, for courses on tropical soils, and reference for scientists and professionals.
Download or read book Agronomy News written by and published by . This book was released on 1978 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sept.-Oct. issue includes list of theses and dissertations for U.S. and Canadian graduate degrees granted in crop science, soil science, and agronomic science during the previous academic year.
Download or read book Lime Effects on Phosphorus Retention and Release in Highly Weathered Soils written by Handi Wang and published by . This book was released on 1986 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Stabilization of Soil Organic Matter by Iron Oxide in Highly Weathered Tropical Soils written by and published by . This book was released on 2013 with total page 396 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 Phosphorus Requirements for Sustainable Agriculture in Asia and Oceania written by International Council of Scientific Unions. Scientific Committee on Problems of the Environment and published by Int. Rice Res. Inst.. This book was released on 1990 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This symposium organised by the International Rice Institute concentrate on the P requirement to optimize food and fiber production in the main rice-growing areas of the world using Asia and Oceanic data in a regional case study. Research gaps and needs are discussed
Download or read book Plant Responses to Phosphorus deficiency Stress written by Sarah Elizabeth Johnson and published by . This book was released on 1999 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphate deficiency is fiequently a limiting factor in crop production on acid soils due to the tendency of iron oxides to strongly bind phosphate through inner-sphere ligand adsorption. Two of the reported responses of some plants to P-deficiency stress are organic-acid exudation from the roots and increased phosphatase activity. Organic-acid-induced P release from iron-oxide surfaces was studied using synthetic iron oxides. The amounts of P released and Fe dissolved fiom ferrihydrite and goethite at pH 4.0, 5.5, and 7.0 by citric, malic, malonic, oxalic, succinic, and tartaric acids were measured. At low initial P-adsorption levels, ligand-induced dissolution of the oxide surface as the primary mechanism of P release from oxides was supported by the strong positive relationship between Fe dissolved and P released. At higher initial P-adsorption levels, ligand exchange played a greater role in P release. Ten cultivars of sorghum exhibiting a range of P efficiencies were obtained from EMBRAPA in Brazil and tested for organic-acid exudation and phosphatase activity under P-deficiency stress in hydroponic culture. HPLC analysis of root exudates revealed increases in oxalate and succinate under P-deficient conditions, with significant differences between cultivars. There was no evidence of citrate in the root exudates at either P leveI. Western blots using arabidopsis purple acid-phosphatase antibodies revealed varying increases in phosphatase activity under P deficiency among the different cultivars. It was concluded that organic-acid exudation might not be expected to significantly improve P uptake by plants grown on weathered soils dominated by well crystalline iron oxide under low P-fertility conditions. Under higher initial P-fertility conditions, organic-acid exudation might play a greater role in plant P acquisition.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1967 with total page 1374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phosphorus Reactions with Soils High in Iron Oxides written by Uddanapalli Subbarayappa Sree Ramulu and published by . This book was released on 1966 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cycles of Soils written by F. J. Stevenson and published by Wiley-Interscience. This book was released on 1986-01-17 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The carbon cycle. Carbon balance of the soil and role of organic matter in soil fertility. Environmental aspects of the soil carbon cycle. The nitrogen cycle in soil: global and ecological aspects. The international cycle of nitrogen in soil. Impact of nitrogen on health and the environment. The phosporus cycle. The sulfur cycle. The micronutrient cycle.
Download or read book Soil Atlas of Asia written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 2023-07-12 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Commission’s Joint Research Centre and FAO's Global Soil Partnership collaborated with experts from across Asia and other regions to produce the first-ever Soil Atlas of Asia. The aim of the Atlas is to raise awareness about the significance of soil to life in Asia among a wide range of audiences, including the general public, decision makers, politicians, teachers, and scientists from other disciplines. The Atlas comprises a series of annotated maps that demonstrate the diversity of soil characteristics across Asia in an easy-to-understand manner. It also explains how soils are formed, the key factors that shape soil characteristics, and why these vary across the continent. Moreover, the Atlas emphasizes the role of soils in shaping our daily lives and highlights the growing pressures on soils resulting from urban expansion, inappropriate land management, pollution, increased demand for food, and climate change. The Atlas encourages people to understand how their actions can help protect and restore soils while reducing degradation processes.
Download or read book Sorghum for Acid Soils written by Lynn M. Gourley and published by CIAT. This book was released on 1987 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil in the tropics, classification and characteristics; phosphorus availability in the acid soils of tropical America; analysis methodologyfor tropical soils; strategies implied in the use and management of acid soils in Tropical America; a new methodology to select cultivars tolerant to aluminium and with high yield potential; calcium and root penetration in highly weathered soils; sorghum evaluation in the Llanos of Venezuela; potential role of grains sorghum in the agricultural systems of regions with acid soils in tropical latin america; effective screening techniques for tolerance to aluminium toxicity; tolerance to aluminium toxicity in upland rice for acid soils; breeding methodologyfor phosphorus efficiency and tolerance to aluminium and manganesetoxicities for beans (Phaseolus vulgaris L.); world sorghum germplasm collection and conservation; prospects for sorghum improvement for phosphorus efficiency; evaluation of mineral elements in sorghum grown onacid tropical soils; breeding aluminum-tolerant sorghums; finding and utilizing exotic al-tolerant sorghum germplasm.
