| 土壤酸化对砷在团聚体中的分配及其有效性的影响 |
| 摘要点击 920 全文点击 175 投稿时间：2024-02-27 修订日期：2024-05-21 |
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| 中文关键词 土壤酸化 团聚体 砷（As） 形态 有效砷 |
| 英文关键词 soil acidification aggregates arsenic（As） form available arsenic |
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| 中文摘要 |
| 采用以空间换时间的时空替代法,采集不同酸化程度的黄壤和紫色土,分析酸化对土壤团聚体组成和性质的影响,探索砷（As）在不同酸化程度土壤团聚体中的分配特征、赋存形态和有效性,揭示制约土壤As有效性的关键因素. 结果表明,总As在各团聚体中的分配受到其质量分数显著正向影响,质量分数越大总As分配越多. 土壤酸化破坏团聚体结构使大团聚体S1（>2 mm）质量分数下降5~15个百分点,导致无定形铁含量上升2~7倍,进而使S1总As分配量下降. 有效As受到非专性/专性吸附态砷（F1和F2）正向调控（F1+F2相关系数0.76）,受到残渣态砷（F5）反向影响（相关系数为-0.89）. 土壤酸化使外源As进入土壤后F1与F2占比显著下降,导致ω（有效As）由6.71~15.37 mg·kg-1下降到2.36~9.26 mg·kg-1,S1和微团聚体S4（<0.25 mm）中外源有效As含量最高,同时外源有效As还受到有机质反向影响（相关系数-0.72）,有效磷和CEC的正向调控（系数0.40和0.52）. 制约不同粒径团聚体中As有效性的土壤性质因素存在差异,S2（1~2 mm）、S3（0.25~1 mm）和S4这3种团聚体中土壤酸化显著提高无定形铁从而降低As有效性,S3外源有效As受到CEC影响不显著,但所有团聚体外源添加As后有效As都受到有机质、氮和钾的影响. 研究结果可为土壤As有效性的精准调控与污染修复提供基础依据. |
| 英文摘要 |
| The spatiotemporal substitution method was used to collect yellow soil and purple soil with different acidification degrees； analyze the effects of acidification on the composition and properties of soil aggregates； explore the distribution characteristics, occurrence forms, and availability of arsenic （As） in soil aggregates with different acidification degrees； and reveal the key factors restricting the availability of soil As. The results showed that the distribution of total As in each aggregate was positively affected by its mass fraction, and the larger the mass fraction, the more the total As distribution. Soil acidification destroyed the aggregate structure, reduced the mass fraction of large aggregate S1 （>2 mm） by 5 to 15 percentage points, led to the increase in amorphous iron content by 2 to 7 times, and decreased the total As distribution of S1. The available As was positively regulated by non-obligate/obligate adsorptive arsenic （F1, F2） （F1+F2 correlation coefficient 0.76） and negatively affected by residual arsenic （F5） （correlation coefficient -0.89）. Soil acidification significantly reduced the ratio of F1 to F2 after exogenous As entered the soil, resulting in a decrease in ω （available As） from 6.71-15.37 mg·kg-1 to 2.36-9.26 mg·kg-1, and the highest exogenous available As content was found in S1 and microaggregate S4 （<0.25 mm）. Simultaneously, exogenous available As was also negatively affected by organic matter （correlation coefficient -0.72） and positively regulated by available phosphorus and CEC （coefficients 0.40 and 0.52, respectively）. There were differences in soil property factors that restricted the availability of As in aggregates of different particle sizes. Soil acidification in S2 （1-2 mm）, S3 （0.25-1 mm）, and S4 aggregates significantly increased the amorphous iron and thus reduced the availability of As, and the exogenous available As in S3 was not significantly affected by CEC. However, the effective As from all agglomerated sources was affected by organic matter, nitrogen, and potassium. The results provide a basis for the accurate control of soil As availability and pollution remediation. |
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