有机酸对土壤磷的活化利用研究进展

Research on the activation and regulation of soil phosphorus by organic acids

近年来,随着磷肥的大量投入,我国农田土壤中的磷大量累积且呈增长趋势,进而加剧了水体污染和磷矿耗竭的风险,因此,合理利用土壤中的累积磷对农业生产可持续发展和生态环境保护至关重要。本文运用VOSviewer关键词共现分析、数据统计分析等方法,对土壤磷活化文献进行了分析,包括有机酸的种类、有机酸活化磷素的研究概况、有机酸活化磷素的效果、影响因素及活化机制。结果表明:有机酸活化磷的研究在国际上依然是热点;有机酸可以通过促进高稳性磷向活性磷转化,显著提高土壤有效磷含量,提高幅度达到10~1 000倍;有机酸的活化效果受其种类、浓度以及土壤类型的影响,其中柠檬酸和草酸在众多有机酸中的活化效果最为显著,且磷素活化量随有机酸浓度的升高而增加;在石灰性和中性土壤上草酸的活化效果最强,在酸性土壤上柠檬酸的活化效果最强;活化机制主要包括酸溶解作用、络合作用和竞争吸附,三者协同作用促进磷素活化。在此基础上,对有机酸活化土壤磷素进行了总结及展望,以期为我国土壤磷资源的高效利用及水环境保护提供理论依据和实践方法。

In recent years, soil available phosphorus content of farmland soil in China has increased, aggravating the risk of water pollution and phosphate rock depletion. Therefore, rational utilization of accumulated phosphorus in soil is very important for sustainable development of agricultural production and ecological environment protection. In this paper, VOSviewer keyword co-occurrence analysis and statistical analysis were used to analyze the literature on soil phosphorus activation, including the types of organic acids, research overview of organic acid-activated phosphorus, including results, influencing factors, and activation mechanisms of organic acid-activated phosphorus. The analysis found that research on organic acid-activated phosphorus was still a hot topic in the world. Organic acid can remarkably improve available phosphorus content of the soil by promoting the conversion of high-stability phosphorus to active phosphorus by 10-1 000 times. The activation effect of organic acid is affected by its type, concentration, and soil type. Citric acid and oxalic acid had the most significant activation effects among the organic acids analyzed, and activated phosphorus content increased with increasing organic acid concentration. Oxalic acid had the strongest activation effect in calcareous and neutral soils, while citric acid had the strongest activation effect in acidic soil. The activation mechanisms mainly included acid dissolution, complexation, and competitive adsorption, and the synergistic effect of these three mechanisms promoted the activation of phosphorus. Based on these results, the paper summarized the study of activation of soil phosphorus by organic acid, which will help provide important theoretical basis and practical methods for efficient utilization of soil phosphorus resources and water environment protection.