Journal ArticleDOI
Bioavailability of soil inorganic P in the rhizosphere as affected by root-induced chemical changes: A review
TLDR
In this paper, the authors give an overview of those chemical processes that are directly induced by plant roots and which can affect the concentration of P in the soil solution and, ultimately, the bioavailability of soil inorganic P to plants.Abstract:
In most soils, inorganic phosphorus occurs at fairly low concentrations in the soil solution whilst a large proportion of it is more or less strongly held by diverse soil minerals. Phosphate ions can indeed be adsorbed onto positively charged minerals such as Fe and Al oxides. Phosphate (P) ions can also form a range of minerals in combination with metals such as Ca, Fe and Al. These adsorption/desorption and precipitation/dissolution equilibria control the concentration of P in the soil solution and, thereby, both its chemical mobility and bioavailability. Apart from the concentration of P ions, the major factors that determine those equilibria as well as the speciation of soil P are (i) the pH, (ii) the concentrations of anions that compete with P ions for ligand exchange reactions and (iii) the concentrations of metals (Ca, Fe and Al) that can coprecipitate with P ions. The chemical conditions of the rhizosphere are known to considerably differ from those of the bulk soil, as a consequence of a range of processes that are induced either directly by the activity of plant roots or by the activity of rhizosphere microflora. The aim of this paper is to give an overview of those chemical processes that are directly induced by plant roots and which can affect the concentration of P in the soil solution and, ultimately, the bioavailability of soil inorganic P to plants. Amongst these, the uptake activity of plant roots should be taken into account in the first place. A second group of activities which is of major concern with respect to P bioavailability are those processes that can affect soil pH, such as proton/bicarbonate release (anion/cation balance) and gaseous (O2/CO2) exchanges. Thirdly, the release of root exudates such as organic ligands is another activity of the root that can alter the concentration of P in the soil solution. These various processes and their relative contributions to the changes in the bioavailability of soil inorganic P that can occur in the rhizosphere can considerably vary with (i) plant species, (ii) plant nutritional status and (iii) ambient soil conditions, as will be stressed in this paper. Their possible implications for the understanding and management of P nutrition of plants will be briefly addressed and discussed.read more
Citations
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Journal ArticleDOI
Phosphorus acquisition and use: critical adaptations by plants for securing a nonrenewable resource
TL;DR: Physiological, biochemical, and molecular studies of white lupin and other species response to P-deficiency have identified targets that may be useful for plant improvement, and Genomic approaches involving identification of expressed sequence tags found under low-P stress may also yield target sites for plant improved.
Journal ArticleDOI
Plant growth-promoting rhizobacteria (PGPR): emergence in agriculture
TL;DR: The progress to date in using the rhizosphere bacteria in a variety of applications related to agricultural improvement along with their mechanism of action with special reference to plant growth-promoting traits are summarized and discussed in this review.
Journal ArticleDOI
Phosphate Acquisition
TL;DR: In this paper, molecular, biochemical and physiological factors associated with phosphate acquisition by plants are described. But the authors do not consider the effect of mycorrhizal symbiosis on the ability of plants to acquire Pi.
Journal ArticleDOI
Acquisition of phosphorus and nitrogen in the rhizosphere and plant growth promotion by microorganisms
Alan Richardson,José Miguel Barea,Ann McNeill,Claire Prigent-Combaret,Claire Prigent-Combaret +4 more
TL;DR: Features of the rhizosphere that are important for nutrient acquisition from soil are reviewed, with specific emphasis on the characteristics of roots that influence the availability and uptake of phosphorus and nitrogen.
Journal ArticleDOI
Carbon flow in the rhizosphere: carbon trading at the soil–root interface
TL;DR: Due to the importance of rhizodeposition in regulating ecosystem functioning, it is critical that future research focuses on resolving the quantitative importance of the different C and N fluxes operating in the rhizosphere and the ways in which these vary spatially and temporally.
References
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Book
The Mineral Nutrition of Higher Plants
M. H. Martin,H. Marschner +1 more
TL;DR: This chapter discusses the relationship between Mineral Nutrition and Plant Diseases and Pests, and the Soil-Root Interface (Rhizosphere) in Relation to Mineral Nutrition.
Book
Mineral Nutrition of Higher Plants
TL;DR: In this article, the authors discuss the relationship between mineral nutrition and plant diseases and pests, and diagnose deficiency and toxicity of mineral nutrients in leaves and other aerial parts of a plant.
Book
Principles of plant nutrition
Konrad Mengel,Ernest A. Kirkby +1 more
TL;DR: In this article, the Soil as a Plant Nutrient Medium is discussed and the importance of water relations in plant growth and crop production, and the role of water as a plant nutrient medium.
Book
Chemical equilibria in soils
TL;DR: In this paper, Chemical equilibria in soils, chemical equilibrium in soil, Chemical equilibrium in soils, مرکز فناوری اطلاعات و اشعر رسانی, ک-شاouرزی
Book ChapterDOI
The Iron Oxides
R. M. Cornell,U. Schwertmann +1 more
TL;DR: The food-quality iron oxides are primarily distinguished from technical grades by their comparatively low levels of contamination by other metals; this is achieved by the selection and control of the source of the iron or by the extent of chemical purification during the manufacturing process as discussed by the authors.