硫肥对伴矿景天修复镉污染土壤的影响

为探索穴施硫粉和硫酸亚铁肥对伴矿景天（Sedum plumbizincicola）修复中性Cd污染土壤的影响，筛选不同硫肥最佳施用量以提高植物提取效率，在阳朔县兴坪镇思的村土壤Cd全量为0.65 mg·kg^-1的农田上，采用田间小区试验方法，设计穴施低、中、高剂量硫粉、硫酸亚铁等7个处理，对比监测了强化修复前后土壤pH、Cd全量、有效态Cd含量和伴矿景天生物量及Cd含量。结果表明：与不施用硫肥的处理（CK）相比，60 d后穴施不同硫肥处理有效降低了土壤pH，提高了土壤有效态Cd含量，同时有效提高了伴矿景天地上部生物量和Cd含量。通过处理效果与成本对比可知，每公顷穴施79 kg硫粉、252 kg硫酸亚铁效果较好，与CK相比，土壤pH分别降低了0.94、0.67个单位，土壤有效态Cd含量分别提高了111.5%、169.5%，伴矿景天地上部生物量分别提高了11.9%、40.7%，地上部Cd含量分别提高了48.5%、132.1%，地上部Cd提取量分别提高了65.8%、226.3%。研究表明，硫粉和硫酸亚铁肥均是伴矿景天修复中性Cd污染农田土壤的潜在强化提取剂，且硫酸亚铁处理修复效率显著高于硫粉处理。

Phytoremediation efficiency of cadmium-contaminated arable land by planted Sedum plumbizincicola with sulfur fertilization

This study sought to explore the effect of sulfur powder and ferrous sulfate fertilizer on the restoration of neutral Cdcontaminated soil by Sedum plumbizincicola. The optimal application rate of different sulfur fertilizers was selected to improve the phytoextraction efficiency of Cd. On the farmland with a total soil Cd content of 0.65 mg·kg^-1 in Sidi Village, Xingping Town, Yangshuo County, using the field test method, 7 treatments including low, medium, and high doses of sulfur powder and ferrous sulfate were designed. The soil pH, total soil Cd content, and available Cd content were tested, and S. plumbizincicola biomass and Cd content were determined. The results showed that, compared to CK, the hole application of S fertilizers for 60 d effectively reduced soil pH and increased soil available Cd content, and effectively increased the shoot biomass and Cd content of S. plumbizincicola. The comparison of treatment effect and cost showed that hole application of 79 kg sulfur powder or 252 kg ferrous sulfate per hectare had optimal phytoextraction rates. Compared with CK, the above-mentioned treatments reduced the soil pH by 0.94 and 0.67, and increased soil available Cd content by 111.5% and 169.5%, respectively. The shoot biomass of S. plumbizincicola increased by 11.9% and 40.7%, the shoot Cd content increased by 48.5% and 132.1%, and the shoot Cd extraction increased by 65.8% and 226.3%, respectively. Therefore, there are potential enhanced phytoextraction agents for S. plumbizincicola to remediate neutral Cd-contaminated soil. Among them, the repair efficiency of ferrous sulfate treatment is significantly higher than that of sulfur powder treatment.