水稻秸秆炭及组合改良剂对石漠化地区土壤-玉米系统中重金属迁移特征影响

化学固定是重金属污染土壤修复及改良技术之一。通过盆栽实验，研究了水稻秸秆炭及其与石灰、磷酸盐组合改良剂对石漠化土壤-玉米体系中As、Zn和Pb 3种重金属迁移的影响，分析了玉米及土壤重金属含量、形态变化。结果表明，几种改良剂均显著促进了玉米生长，地上部分生物量：水稻秸秆炭 > 石灰+水稻秸秆炭 > 石灰 > 秸秆 > 磷酸盐+水稻秸秆炭 > 磷酸盐 > 对照。水稻秸秆炭、石灰及其组合均能够提高土壤pH值，抑制重金属向玉米地上部分迁移。添加改良剂后土壤中As的弱酸提取态和可还原态含量显著降低，均小于3 mg·kg-1。水稻秸秆炭、秸秆与石灰及其组合均能够降低土壤中重金属提取态和还原态量，能够降低玉米籽粒中重金属的含量，但玉米籽实中Pb依然超标。

Effects of straw biochar and amendments on heavy metals translocation in corn-soil system in rocky desertification area

Chemical fixation is one of remediation techniques for heavy metal contaminated soils. This potted experiment was designed to examine and evaluate the effects of straw biochar and its combined amendments (lime and phosphate) on heavy metals (Pb, Zn and As) content and speciation in soil, soil chemical properties, corn growth and heavy metals accumulation in corn. The results showed that three amendments (lime, straw, straw biochar) could promote corn growth, and increase the total dry weight of shoots and roots. Aboveground biomass in descending order of biochar > lime+biochar > lime>straw > phosphate+biochar > phosphate > control. Biochar, lime and their combinations could increase soil pH value and inhibit heavy metal migration to the corn. Weak acid extractable and reducible As of content significantly reduce in soil after adding amendments, and the concentrations-1. Biochar and their combinations with lime and straw could decline extractable and reductive heavy metals in soil, and also could decrease metal content in corn seeds, but Pb concentrations were higher than significantly exceed food safety standards. Though soil amendments could decrease the accumulation of heavy metals in seeds, improve corn growth and development, moderate degree of heavy metal contaminated soil unsuitable for planting corn.