含磷材料对土壤重金属有效性及微生物响应

Effects of Phosphorus-containing Amendments on Cd,Cu,Pb,and Zn Availability and Microbial Community Structure in Soils

为揭示含磷钝化剂对土壤重金属的钝化效果和土壤环境健康的影响,该研究以广东某电子废物拆解区农田耕作土为研究对象,利用盆栽试验,一次性添加钙镁磷肥(PF)、海泡石(SE)、钙镁磷肥与海泡石配施(SP),探讨了土壤中镉铜铅锌有效性和土壤微生物群落结构的变化。结果表明:仅单施钙镁磷肥使土壤Cd有效性显著降低了23.8%,而钙镁磷肥和海泡石配施显著降低了土壤Zn、Cd、Pb和Cu的有效性,降低幅度依次为46.4%(Zn)>42.9%(Cd)>27.4%(Pb)>11.2%(Cu);单施海泡石对土壤Cd和Pb有效态含量无显著影响。钙镁磷肥和海泡石配施显著提高土壤过氧化氢酶和脲酶活性,分别为对照的3.3和4.1倍;单施钙镁磷肥也显著提高土壤过氧化氢酶和脲酶活性,分别为对照的2.9和5.1倍,然而单施海泡石则对2种酶活性没有显著影响;钙镁磷肥和海泡石配施后、单施钙镁磷肥均显著提高了玉米地上部和地下部的生物量,单施海泡石则对玉米生物量没有显著影响;钙镁磷肥和海泡石配施配施后,土壤Ochrobactrum、Anaerolinea、Achromobacter、Clostridium等有益微生物属的丰度明显提高,土壤有机质含量和阳离子交换量是影响微生物群落结构的关键因素。该研究可为重金属污染土壤的绿色可持续修复提供依据。

In order to elucidate the effects of phosphorus-containing amendments on soil heavy metal and soil health,a pot trial was conducted.Three amendments,including calcium magnesium phosphate fertilizer(PF),sepiolite(SE),and calcium magnesium phosphate fertilizer combined sepiolite(SP)were added to soils,which collected from an electronic waste recycling region in Guangdong,to examine the effects on Cd,Cu,Pb,and Zn availabilities,and environmental responses of soil microbial community structure.Results showed that the application of PF decreased the availability of Cd by 23.8%,while the application of SP significantly decreased the availabilities of Zn,Cd,Pb,and Cu by 46.4%,42.9%,27.4%,and 11.2%,respectively.Consistently,the activities of catalase and urease in SP amended soils were 3.3 and 4.1 times higher than those of the control,respectively.Moreover,the activities of catalase and urease were increased 2.9 and 5.1 times in the treatment of PF compared with the control,respectively,whereas no enhancement was observed in the SE amended soil.The combined amendment of calcium magnesium phosphate fertilizer and sepiolite,and only calcium magnesium phosphate fertilizer application significantly increased the aboveground and underground biomass of corn,while sepiolite application had no significant effect on it.The application of SP greatly enhanced the abundance of beneficial bacterial genera,such as Ochrobactrum,Anaerolinea,Achromobacter and Clostridium,which was mainly influenced by the contents of soil organic matter and cation exchange capacity.Overall,this study could provide a basis method for sustainable and ecological remediation of heavy metal contaminated soils.