Studies on P Fractions and their Relationship with Soil Properties. Distribution of different P fractions and their relationship with soil properties

      Аннотация: Phosphorus is one of the essential element for both plant and animal life. The chemistry of soil phosphorus is complex owing to the ability of each phosphate ion to form a multiplicity of compounds of different composition and variable solubilities. Phosphorus exists in soils both in inorganic and organic forms. The inorganic P mainly occurs as fluor-apatite, carbonate-apatite and oxy-apatite, mono, di and tri-Ca-P and Fe-P and Al-P. Organic P is present mainly as phytin and its derivatives, nucleic acid and phospholipids. In soils, 20-85% of the total P is in organic form, but plant can utilize organic P only after it is mineralized. The plants mainly depend upon inorganic P forms (H2PO4-, HPO42-, PO43- depend on soil pH) for their P requirement. Phosphorus adsorption by soils has a important role in sustaining and building up phosphorus supplying capacities of soils. Transformation of P into insoluble and unavailable compounds is considered as primary cause of inefficient utilization of phosphatic fertilizers.

Ключевые слова: properties, soil, Phosphorus Fractions