Report on Physical, Chemical and Biological Methods to Improve P Uptake by Crops

Phosphorus (P) is an essential plant nutrient for energy transfer, photosynthesis, and cell division during growth, but its management in soil remains complex and challenging. Applied P fertilizers react in the soil, entering into equilibrium with less soluble phosphorus pools. These reactions are reversible and depend on the P concentration in the soil solution. Efficient phosphorus use requires fertilizers that supply P when and where crops need it while minimizing losses.Novel formulations, including coated fertilizers, humic substances, microbial inoculants, and nanomaterials, aim to improve P availability and use efficiency (PUE). Coated fertilizers show promise by matching P release with crop demand, especially in low-P or high-fixation soils and may reduce seedling damage. However, their success depends on product cost, field performance, and compatibility with the 4R nutrient stewardship.Humic substances and microbial inoculants such as mycorrhizae and phosphorus-solubilizing organisms can enhance P availability in pot or greenhouse settings, but their benefits in the field are inconsistent. Similarly, pH-modifying additives and ion-sequestering agents show potential but have variable performance and may not be economically viable.Recycled products like struvite, graphene oxides, and layered double hydroxides are slow-release P sources that can be environmentally beneficial. Blending these with soluble P fertilizers may ensure both early and sustained P supply. However, their low nutrient concentration and high cost can limit practical use.Ultimately, several emerging P fertilizers show promise in controlled environments but require further testing under varying field conditions in conjunction with 4Rs management practices. Future research could explore optimizing the economic and agronomic performance of innovative P fertilizer formulations across different soils and cropping systems to ensure they contribute to sustainable and profitable agriculture. Balancing P removal with replenishment remains essential to avoid long-term soil nutrient depletion.