Abstract Phosphorus (P) is an essential macronutrient that plays a central role in plant metabolism, particularly in energy transfer, nucleic acid synthesis, membrane formation, and overall crop development. Although many soils contain substantial total phosphorus reserves, only a very small proportion is directly available to plants because most soil phosphorus occurs in poorly soluble inorganic compounds or in organic forms requiring biological mineralization. This paper presents a literature-based synthesis of the main forms of phosphorus in soil, the factors controlling its mobility and availability, and the effects of organic fertilization on phosphorus dynamics, with particular emphasis on poultry manure. The reviewed literature indicates that soil phosphorus behavior is governed by parent material, pH, mineralogical composition, soil texture, organic matter content, microbial activity, and long-term fertilization history. Organic amendments such as farmyard manure, compost, sewage sludge, and crop residues may increase phosphorus availability by contributing both organic and inorganic P, stimulating phosphatase activity, modifying sorption processes, enhancing microbial turnover, and improving soil aggregation. However, repeated or excessive organic fertilization may also result in phosphorus accumulation and elevated environmental risk through runoff, erosion, or leaching, particularly in coarse-textured soils or under phosphorus-surplus management. Poultry manure is of particular agronomic interest because of its relatively high phosphorus content and the presence of soluble and moderately labile P forms, which can enhance plant uptake but also increase the potential for off-site phosphorus transfer. Overall, sustainable phosphorus management requires the integration of agronomic and environmental considerations and a more comprehensive understanding of both organic and inorganic soil phosphorus pools.

phosphorous in soil, poultry manure, organic fertilization

agronomy

Presentation: poster