Review on the effect of biochar on soil phosphorus transformation and mechanisms

ObjectivesTotal amount and morphologic changes of soil phosphorus are important factors of influencing its function as a nutrient element and causing potential threaten to environment. As a kind of new exogenous material, biochar is of great importance in adjusting soil phosphorus transformation. This paper reviewed the research progress of biochar effect on soil phosphorus transformation in agricultural ecosystem, and discussed related action mechanisms, which was aimed at providing theoretical basis for biochar application on the migration and transformation of phosphorus in farmland soil.

Major advancesSoil available phosphorus content could be significantly increased with the application of biochar. There are four main approaches in the reported results.Biochar contains high level of P in themself, so biochar can be used as an effective phosphorus source. Biochar could regulate soil pH, adsorb the complex of soil phosphorus and metal, and provide carbon nutrient for soil microorganism.

Further research neededThe proper type and application amount in low fertility soils need to be clearified to prevent the unbalance of nutrient supply. The potential of decreasing phosphorous fertilizer input should be considered because of the high level of P content in biochar. More attention should be paid in the interaction of biochar with rizhosphere soil nutrient, which is more closely related with the availability of soil phosphorous availability. As a relatively new soil remediation material, the long term effect of biochar after applied into soil should be examined and evaluated for the cost effective use.