低分子量有机酸对土壤磷活化及其机制研究进展

Review on the effects of low-molecular-weight organic acids on soil phosphorus activation and mechanisms

近30年来,过量施用磷肥导致土壤磷素累积继而引起水体富营养化等问题备受关注。植物根系分泌的低分子量有机酸能活化土壤积累态磷,提高土壤磷素有效性,已成为研究热点问题之一。本文结合国内外已有研究,从低分子量有机酸的类型、添加浓度、土壤类型和土壤磷素水平等方面总结了低分子量有机酸活化土壤无机磷与有机磷的效果,并通过对比土壤磷活化试验前后各形态磷的变化探讨了低分子量有机酸对土壤磷的活化机制。低分子量有机酸对土壤无机磷的活化主要是促进了土壤中有效性低的无机磷形态向有效性较高的形态转化,而低分子量有机酸对土壤有机磷的活化结论尚不一致,活化机制也不明确,仍需进一步研究。未来研究应关注低分子量有机酸与磷肥之间的协同增效机制,并进一步探索低分子量有机酸对土壤磷素(特别是有机磷)的活化机制。

Over the last 30 years,water eutrophication caused by excessive application of phosphorus（ P） fertilizer to soil has attracted much attention. Low-molecular-weight organic acids in root exudates can mobilize the accumulated P in soils and thus enhance P availability,which has become a research hotspot. We reviewed recent advances about the activation effects of low-molecular-weight organic acids on soil inorganic and organic P,as well as the activation mechanisms by comparing the changes of different P forms in experiments before and after soil P activation.Release of soil inorganic P induced by low-molecular-weight organic acids mainly contributes to P transformation from low availability to high availability. However,release mechanisms of soil organic P induced by low-molecular-weight organic acids are still not clear,which needs to be further studied. Future studies should focus on the synergistic mechanisms between low-molecularweight organic acids and P fertilizers. Moreover,more studies are needed on the release mechanisms of soil P（ especially organic P） induced by low-molecular-weight organic acids.