The Experts below are selected from a list of 115740 Experts worldwide ranked by ideXlab platform
Robert J Zasoski - One of the best experts on this subject based on the ideXlab platform.
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mapping soil Micronutrients
Field Crops Research, 1999Co-Authors: Jeffrey G White, Robert J ZasoskiAbstract:Abstract Soils vary widely in their Micronutrient content and in their ability to supply Micronutrients in quantities sufficient for optimal crop growth. Soils deficient in their ability to supply Micronutrients to crops are alarmingly widespread across the globe, and this problem is aggravated by the fact that many modern cultivars of major crops are highly sensitive to low Micronutrient levels. Original geologic substrate and subsequent geochemical and pedogenic regimes determine total levels of Micronutrients in soils. Total levels are rarely indicative of plant availability, however, because availability depends on soil pH, organic matter content, adsorptive surfaces, and other physical, chemical, and biological conditions in the rhizosphere. Micronutrient availability to plants can be measured in direct uptake experiments, or estimated with techniques that correlate quantities of Micronutrients extracted chemically from soils to plant uptake and response to Micronutrient fertilization. Rational management of Micronutrient fertility and toxicity requires an understanding of how total and plant-available soil Micronutrients vary across the land. A variety of approaches have been used to survey and map the geographic distribution of soil Micronutrient content and availability at scales ranging from global to sites within single production fields. Soil Micronutrient maps covering large areas improve our understanding of the nature and extent of Micronutrient problems, and aid in determining their relationships with climate, soil properties, and soil genetic characteristics determined at similar scales, for example, Soil Taxonomy to the order, sub-order, or great group levels. Intermediate scale maps can be useful in delineating specific areas where deficiencies or toxicities are likely for agriculture, and in determining localized soil characteristics that may be associated with such problems. Highly detailed maps of soil Micronutrient content and availability in individual fields are being developed for site-specific precision agriculture. Soil Micronutrient maps have fostered discovery of relationships between soil Micronutrient content and availability and some human and livestock health problems such as goiter, Keshan and Kaschin–Beck diseases, and cancer. Advances including the global positioning system (GPS), geographic information systems (GIS), inductively coupled plasma (ICP) spectrometry, geostatistics, and precision agriculture facilitate soil Micronutrient mapping and provide quantitative support for decision and policy making to improve agricultural approaches to balanced Micronutrient nutrition.
R.b. Clark - One of the best experts on this subject based on the ideXlab platform.
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Micronutrients in Crop Production
Advances in Agronomy, 2002Co-Authors: Nand Kumar Fageria, Virupax C. Baligar, R.b. ClarkAbstract:The essential Micronutrients for field crops are B, Cu, Fe, Mn, Mo, and Zn. Other mineral nutrients at low concentrations considered essential to growth of some plants are Ni and Co. The incidence of Micronutrient deficiencies in crops has increased markedly in recent years due to intensive cropping, loss of top soil by erosion, losses of Micronutrients through leaching, liming of acid soils, decreased proportions of farmyard manure compared to chemical fertilizers, increased purity of chemical fertilizers, and use of marginal lands for crop production. Micronutrient deficiency problems are also aggravated by the high demand of modern crop cultivars. Increases in crop yields from application of Micronutrients have been reported in many parts of the world. Factors such as pH, redox potential, biological activity, SOM, cation-exchange capacity, and clay contents are important in determining the availability of Micronutrients in soils. Plant factors such as root and root hair morphology (length, density, surface area), root-induced changes (secretion of H + , OH − , HCO 3 − ), root exudation of organic acids (citric, malic, tartaric, oxalic, phenolic), sugars, and nonproteinogenic amino acids (phytosiderophores), secretion of enzymes (phosphatases), plant demand, plant species/cultivars, and microbial associations (enhanced CO 2 production, rhizobia, mycorrhizae, rhizobacteria) have profound influences on plant ability to absorb and utilize Micronutrients from soil. The objectives of this article are to report advances in research on the Micronutrient availability and requirements for crops, in correcting deficiencies and toxicities in soils and plants, and in increasing the ability of plants to acquire needed amounts of Micronutrient elements.
Jeffrey G White - One of the best experts on this subject based on the ideXlab platform.
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mapping soil Micronutrients
Field Crops Research, 1999Co-Authors: Jeffrey G White, Robert J ZasoskiAbstract:Abstract Soils vary widely in their Micronutrient content and in their ability to supply Micronutrients in quantities sufficient for optimal crop growth. Soils deficient in their ability to supply Micronutrients to crops are alarmingly widespread across the globe, and this problem is aggravated by the fact that many modern cultivars of major crops are highly sensitive to low Micronutrient levels. Original geologic substrate and subsequent geochemical and pedogenic regimes determine total levels of Micronutrients in soils. Total levels are rarely indicative of plant availability, however, because availability depends on soil pH, organic matter content, adsorptive surfaces, and other physical, chemical, and biological conditions in the rhizosphere. Micronutrient availability to plants can be measured in direct uptake experiments, or estimated with techniques that correlate quantities of Micronutrients extracted chemically from soils to plant uptake and response to Micronutrient fertilization. Rational management of Micronutrient fertility and toxicity requires an understanding of how total and plant-available soil Micronutrients vary across the land. A variety of approaches have been used to survey and map the geographic distribution of soil Micronutrient content and availability at scales ranging from global to sites within single production fields. Soil Micronutrient maps covering large areas improve our understanding of the nature and extent of Micronutrient problems, and aid in determining their relationships with climate, soil properties, and soil genetic characteristics determined at similar scales, for example, Soil Taxonomy to the order, sub-order, or great group levels. Intermediate scale maps can be useful in delineating specific areas where deficiencies or toxicities are likely for agriculture, and in determining localized soil characteristics that may be associated with such problems. Highly detailed maps of soil Micronutrient content and availability in individual fields are being developed for site-specific precision agriculture. Soil Micronutrient maps have fostered discovery of relationships between soil Micronutrient content and availability and some human and livestock health problems such as goiter, Keshan and Kaschin–Beck diseases, and cancer. Advances including the global positioning system (GPS), geographic information systems (GIS), inductively coupled plasma (ICP) spectrometry, geostatistics, and precision agriculture facilitate soil Micronutrient mapping and provide quantitative support for decision and policy making to improve agricultural approaches to balanced Micronutrient nutrition.
M Afyuni - One of the best experts on this subject based on the ideXlab platform.
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Micronutrient efficient genotypes for crop yield and nutritional quality in sustainable agriculture a review
Agronomy for Sustainable Development, 2010Co-Authors: Amir Hossein Khoshgoftarmanesh, Rainer Schulin, Rufus L Chaney, Bahareh Daneshbakhsh, M AfyuniAbstract:About 4 billion people will be added onto the present population by 2050. To meet further demand for food, agricultural production should increase on the existing land. Since the Green Revolution, higher crop production per unit area has resulted in greater depletion of soil phytoavailable Micronutrients while less attention has been paid to Micronutrients fertilization. Now, Micronutrient deficiency has become a limiting factor for crop productivity in many agricultural lands worldwide. Furthermore, many food systems in developing countries can not provide sufficient Micronutrient content to meet the demands of their citizens, especially low-income families. There are several solutions such as soil and foliar fertilization, crop systems, application of organic amendments to correct Micronutrients deficiency and to increase their density in edible parts of plants. This review article presents (1) agronomic approaches to improve crop yield and Micronutrient content of food crops, and (2) genotypic variation in uptake and accumulation of Micronutrients. Considering ecological concerns, cultivation and breeding of Micronutrient-efficient genotypes in combination with proper agronomic management practices appear as the most sustainable and cost-effective solution for alleviating food-chain Micronutrient deficiency. Micronutrient-efficient genotypes could provide a number of benefits such as reductions in the use of fertilizers, improvements in seedling vigor, and resistance to abiotic and abiotic stresses. Using bioavailable Micronutrient-dense staple crop cultivars can also be used to improve the Micronutrient nutritional status of human.
Ian S. Young - One of the best experts on this subject based on the ideXlab platform.
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Micronutrients: dietary intake v. supplement use
The Proceedings of the Nutrition Society, 2005Co-Authors: Jayne V. Woodside, D. Mccall, Claire P. Mcgartland, Ian S. YoungAbstract:Whilst clinical deficiency of Micronutrients is uncommon in the developed world, a suboptimal intake of certain Micronutrients has been linked with an increased risk of chronic diseases such as CVD and cancer. Attention has therefore focused on increasing Micronutrient status in order to theoretically reduce chronic disease risk. Increasing Micronutrient status can involve a number of approaches: increasing dietary intake of Micronutrient-rich foods; food fortification; use of supplements. Observational cohort studies have demonstrated an association between high intakes of Micronutrients such as vitamin E, vitamin C, folic acid and beta-carotene, and lower risk of CHD, stroke and cancer at various sites. However, randomised intervention trials of Micronutrient supplements have, to date, largely failed to show an improvement in clinical end points. The discordance between data from cohort studies and the results so far available from clinical trials remains to be explained. One reason may be that the complex mixture of Micronutrients found, for example, in a diet high in fruit and vegetables may be more effective than large doses of a small number of Micronutrients, and therefore that intervention studies that use single Micronutrient supplements are unlikely to produce a lowering of disease risk. Studies concentrating on whole foods (e.g. fruit and vegetables) or diet pattern (e.g. Mediterranean diet pattern) may be more effective in demonstrating an effect on clinical end points. The present review will consider the clinical trial evidence for a beneficial effect of Micronutrient supplements on health, and review the alternative approaches to the study of dietary intake of Micronutrients.
