Solubilization of organic phosphorus sources by cyanobacteria and a commercially available bacterial consortium

Phosphorus (P) is a highly immobile soil nutrient, thus enhancing its availability through mechanisms such as unique, phosphate solubilizing microorganisms (PSMs) may help improve soil-plant P relationships. The objective of this study was to evaluate P solubilization and activity of Anabaena sp. and Mammoth P using two different organic P sources (bone meal and rock phosphate) under laboratory conditions. Treatments were arranged in a full factorial design with three replications, three organic P sources [bone meal (BM), rock phosphate (RP) and control (No P added)], three PSM treatments [control (No PSM), Cyanobacteria (Cyano), Mammoth P (MP)] and six sampling dates over 56 days. There were no significant differences observed in pH across treatments over the 56-day incubation (p = 0.05). The Cyano treatment had greater water-soluble P and Olsen extractable P concentrations under the No P control and RP treatments compared with the No PSM control and MP treatments. In terms of Olsen P concentration, the MP treatment of the BM source was greater than the No PSM control and equal to the Cyano treatment. Results suggest that the Cyano treatment solubilized more P than MP, and thus may be an effective strategy for improving future soil P availability to plants, especially in light of future dwindling rock phosphate reserves.

Automated summary

The study evaluated phosphorus solubilization and activity of Anabaena sp. and Mammoth P using different organic P sources under laboratory conditions. Results showed that the Cyano treatment had higher water-soluble P and Olsen extractable P concentrations compared to the No PSM control and MP treatments. The MP treatment of the bone meal source had higher Olsen P concentration than the No PSM control and same as the Cyano treatment.