本研究的目的是阐明杏壳衍生的生物炭(ASB)和苹果树衍生的生物炭(ATB)对土壤性质的影响,植物生长,微生物群落,酶活性,采矿土壤中Zn和Cd的分馏和植物有效性。从丰县收集了被Zn(1860.0mgkg-1)和Cd(39.9mgkg-1)污染的冶炼厂土壤,中国,用不同剂量治疗(0(对照),1、2.5、5和10%w/w)的两种生物炭,并在温室盆栽实验中由芥菜种植。酸溶性,可还原,可氧化,测定了Zn和Cd的残留量和植物组织浓度。生物炭的添加改善了植物生长(22.6-29.4%),土壤pH值(高达0.94单位),与对照相比,土壤有机质(高达4倍)。ASB和ATB,特别是ATB,降低了Zn和Cd的酸溶性(Zn为21-26%,Cd为15-35%)和可还原(Zn为9-36%,Cd为11-19%),并改变了有机和残留部分中的这些部分。因此,生物炭降低了根中的金属浓度(Zn为36-41%,Cd为33-37%)和芽(Zn为25-31%,Cd为20-29%),这可能是由于pH值的增加,生物炭石灰作用,和生物炭对金属的吸附。生物炭对细菌群落组成的影响是选择性的。ASB和ATB降低了土壤β-葡萄糖苷酶的活性,脱氢酶,和碱性磷酸酶,同时增加脲酶活性。生物炭,特别是ATB,可以被认为是有效的土壤改良剂,可以减少污染土壤中Zn和Cd的植物毒性,改善植物生长,增强特定细菌群的丰度并增加脲酶活性;然而,应重视其对β-葡萄糖苷酶活性的负面影响,脱氢酶,和碱性磷酸酶。
The aim of this study was to elucidate the effects of apricot shell-derived biochar (ASB) and apple tree-derived biochar (ATB) on soil properties, plant growth, microbial communities, enzymatic activities, and Zn and Cd fractionation and phytoavailability in mining soils. Smelter soil contaminated by Zn (1860.0 mg kg-1) and Cd (39.9 mg kg-1) was collected from Fengxian, China, treated with different doses (0 (control), 1, 2.5, 5, and 10% w/w) of both biochars and cultivated by Brassica juncea in a greenhouse pot experiment. The acid-soluble, reducible, oxidizable, and residual fraction and plant tissue concentrations of Zn and Cd were determined. Biochar addition improved plant growth (22.6-29.4%), soil pH (up to 0.94 units), and soil organic matter (up to 4-fold) compared to the control. The ASB and ATB, particularly ATB, reduced the acid-soluble (21-26% for Zn and 15-35% for Cd) and the reducible (9-36% for Zn and 11-19% for Cd) fractions of Zn and Cd and altered these fractions in the organic and residual fractions. Therefore, the biochars decreased the metal concentrations in the roots (36-41% for Zn and 33-37% for Cd) and shoots (25-31% for Zn and 20-29% for Cd), which might be due to the increase in pH, biochar liming effects, and metal sorption by the biochar. The biochars impact on the bacterial community composition was selective. The ASB and ATB decreased the activities of soil β-glucosidase, dehydrogenase, and alkaline phosphatase while increasing the urease activity. The biochars, particularly ATB, can be considered as effective soil amendments for reducing the phytotoxicity of Zn and Cd in contaminated soils, improving plant growth, enhancing the abundance of specific bacterial groups and increasing urease activity; however, more attention should be paid to their negative effects on the activities of β-glucosidase, dehydrogenase, and alkaline phosphatase.