Effects of adding biochar on availability of soil phosphorus: A review

Phosphorus fixation is an important factor in reducing the bioavailability of soil phosphorus. Due to its unique physical and chemical properties, biochar play an important role in improving the availability of soil phosphorus, reducing soil phosphorus fixation, lessening the application of phosphate fertilizer, and promoting sustainable agricultural development and ecological environmental protection. As a long-lasting slow-release phosphorus resource, biochar can reduce the adsorption of phosphorus in the soil, increase the number of microorganisms and enzyme activity, and reduce phosphorus leaching. This article summarized the characteristics of soil pH, microorganisms, adsorption and retention of phosphorus after adding biochar to the soil, and discussed the mechanism of biochar’s influence on soil phosphorus, which was important for further understanding of the effective ways that biochar affected soil phosphorus significance.