Evaluation of Cadmium Bioavailability in Soils Using Diffusive Gradients in Thin Film Technique and Traditional Methods

The developed technique of diffusive gradients in thin film( DGT) has been suggested as a promising tool for evaluation of cadmium( Cd) availability in soils,but there exists considerable debate on its suitability. In this study,Cd bioavailability in soils was systemically investigated by comparing this technique with seven traditional methods, including soil solution concentration and six commonly used extraction methods( HAc,EDTA,Na c,NH4Ac,CaCl2 and MgCl2). Two typical plants( wheat and maize) were examined for Cd uptake. Maize was more sensitive to increasing exposure to Cd in soils than wheat when the added amounts of Cd ranged from 3. 5 to 5. 0 mg · kg-1,accompanied by the significant decreases of shoot and root biomasses. Cd concentrations in shoots and roots of two plants increased continuously with increasing levels of Cd in soils. Cd uptake was higher in wheat than that in maize. The bioavailable concentrations of Cd measured by all methods increased nearly linearly with increasing addition of Cd in soils. Positive correlations were observed between various bioavailable indicators of Cd in soils and Cd concentrations in two plants. The extractable Cd by six chemical extractants was considerably higher for maize than for wheat,while the DGT-measured and soil solution concentrations of Cd were lower for maize than for wheat,following the same trend as plant Cd uptake. The results imply that DGT measurement can effectively predict the bioavailable levels of Cd in soil solutions and that it is an ideal tool for prediction of Cd bioavailability in soils.

Surfactant Linear Alkylbenzene Sulfonate Effect on Soil Cd Fractions and Cd Distribution in Soybean Plants in a Pot Experiment

A pot experiment was conducted to study the effect of an anionic surfactant linear alkylbenzene sulfonate(LAS) application on cadmium(Cd)fractions in soils and Cd distribution in different tissues of soybean(Glycine max)plants as well as soil pH.Soil samples were treated with three levels of Cd(0,5,and 10 mg kg^(-1))and five levels of LAS(0,5, 15,50,and 100 mg L^(-1)).Results indicated that compared to the control soils(no Cd and no LAS treatment),soil pH increased and available Cd decreased in the soil treated with external Cd and watered with LAS solutions.Meanwhile, soil exchangeable Cd and Cd bound to carbonates decreased;Cd bound to amorphous iron and manganese oxides and Cd bound to organic matter increased.In addition,LAS application could reduce enrichment of Cd in soybean plants, resulting in decreased Cd in the soybean plants.Thus,suitable LAS application could decrease bioavailability and mobility of soil Cd.

Chemical fractionations and bioavailability of cadmium and zinc to cole (Brassica campestris L.) grown in the multi-metals contaminated oasis soil,northwest of China

A pot experiment was conducted to study the relationship between distribution of cadmium （Cd） and zinc （Zn） and their availability. to cole （Brassica campestris L.） grown in the multi-metal contaminated oasis soil in northwest of China. The results showed that Cd and Zn in the unpolluted oasis soil was mainly found in the residual fractionation, however, with increasing contents of Cd and Zn in the oasis soil, the distribution of Cd and Zn changed significantly. The growth of cole could be promoted by low Cd and Zn concentration, but significantly restrained by high concentrations. There was antagonistic effect among Cd and Zn in the multi-metals contaminated oasis soil. Stepwise regression analysis between fractionations distribution coefficients of the two meals in the soil and their contents in cole showed that both Cd and Zn in the exchangeable fractionation in the oasis soil made the most contribution on the uptake of Cd and Zn in cole. The bio-concentration factor （BCF） of Cd was greater than Zn in cole, and BCFs of the two metals in leaves were greater than those in roots. The translocation factors of the two metals in cole were greater than 1, and the two metals mainly accumulated in the edible parts in cole. Therefore, cole is not a suitable vegetable for the oasis soil because of the plants notable contamination by heavy metals.

Effects of soil amendments, foliar sprayings of silicon and selenium and their combinations on the reduction of cadmium accumulation in rice

Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of two soil amendments, sodium sulfide-biofuel ash (SSBA) and lime (0.1%), and three foliar applications, silicon (Si, 2.5 mmol L-1), selenium (Se, 40 mg L-1), and their combination (SS), on Cd reduction in rice (Oryza sativa L.) in a pot experiment, which were then verified in a field experiment. Compared with the control without amendment but with spraying of deionized water, both SSBA and lime significantly reduced concentrations of CaCl2-extractable Cd in soil by 30%–39% and 31%–40% and Cd in brown rice by 44%–63% and 53%–72% in the pot and field experiments, respectively. Foliar Si, Se, and SS applications significantly reduced Cd accumulation in brown rice by 62%–64%, 72%–83%, and 39%–73%, respectively, increased rice grain yield, and improved antioxidant enzyme activities in rice leaves but with different trends in the pot and field experiments. Combinations of SSBA and lime with Si, Se, and SS had a non-significant synergistic effect on Cd reduction in brown rice compared to only foliar spraying or soil amendment in both pot and field experiments, although SSBA + Se and SSBA + Si reduced Cd concentration in brown rice by 16%–34% and 14%–24% compared to only foliar Si and Se and soil SSBA applications, respectively. Soil lime application and foliar Si spraying were the most cost-effective strategies to reduce Cd accumulation in brown rice in the field and pot experiments, respectively. Although soil amendments and foliar treatments were individually effective, their combinations failed to generate a significant synergistic reduction of Cd concentration in brown rice.

Iron oxidation-reduction bioavailability in and its impacts on cadmium paddy soils： a review

Redox conditions in paddy soils may vary as they are submerged and drained during rice growth. This change may bring about reductive dissolution of iron （Fe） oxides and subsequent formation of secondary Fe-bearing minerals in rice paddies. The mobility and bioavailability of metal contaminants such as cadmium （Cd） in paddy soils are closely related to the chemical behaviors of Fe. Therefore, in this paper, advances in the study of paddy Fe redox transformations and their effects on Cd availability to rice are briefly reviewed. Current concepts presented in this review include the forms of Fe in paddy soils, the reactions involved in Fe oxidation-reduction, chemical factors affecting Fe redox processes, Cd availability to rice and the impacts of Fe transformation on Cd uptake and translocation in rice. Prospects for future research in this area are also discussed.

Reduction of Soil Cadmium Bioavailability by Using Industrial Byproduct Phosphorus Slag

In this study,an alternative and cost-effective industrial byproduct phosphorus slag(PS)was utilized to treat simulated Cd-contaminated soil.The modified European Community Bureau of Reference(BCR)sequential extraction procedure was applied to assess the ability of PS to reduce Cd mobility in contaminated soil by the incubation experiments.The results showed 2%(W/W)PS reduced the exchangeable fraction of Cd by 99.7%,which also increased the pH,electrical conductivity,cation exchange capacity,available phosphorus,and available silicon of the soil.The results suggested that the PS could decrease Cd bioavailability and improve soil nutrition.This was demonstrated by the pot experiments.The Cd accumulation in both pakchoi(Brassica chinensis L.)leaf and root was reduced along with the reduction of the Cd translocation factor(TF)and the bioaccumulation factors(BCF)in pakchoi.In Cd-contaminated soil(3.16 mg·kg^–1),the 2%(W/W)PS reduced the Cd content in the leaf and root of pakchoi by 70.7%and 58.7%,respectively.Meanwhile,the increase of the chlorophyll content in pakchoi and the promotion of pakchoi root system development suggested healthy plant growth in the PS treated soil.

Soil properties drive the bacterial community to cadmium contamination in the rhizosphere of two contrasting wheat(Triticum aestivum L.)genotypes

Cadmium(Cd)bioavailability in the rhizosphere makes an important difference in grain Cd accumulation in wheat.Here,pot experiments combined with 16S rRNA gene sequencing were conducted to compare the Cd bioavailability and bacterial community in the rhizosphere of two wheat(Triticum aestivum L.)genotypes,a low-Cd-accumulating genotype in grains(LT)and a high-Cd-accumulating genotype in grains(HT),grown on four different soils with Cd contamination.Results showed that there was non-significant difference in total Cd concentration among four soils.However,except for black soil,DTPA-Cd concentrations in HT rhizospheres were higher than those of LT in fluvisol,paddy soil and purple soil.Results of 16S rRNA gene sequencing showed that soil type(52.7%)was the strongest determinant of root-associated community,while there were still some differences in rhizosphere bacterial community composition between twowheat genotypes.Taxa specifically colonized in HT rhizosphere(Acidobacteria,Gemmatimonadetes,Bacteroidetes and Deltaproteobacteria)could participate inmetal activation,whereas LT rhizosphere was highly enriched by plant growth-promoting taxa.In addition,PICRUSt2 analysis also predicted high relative abundances of imputed functional profiles related to membrane transport and amino acid metabolism in HT rhizosphere.These results revealed that the rhizosphere bacterial community may be an important factor regulating Cd uptake and accumulation in wheat and indicated that the high Cd-accumulating cultivar might improve Cd bioavailability in the rhizosphere by recruiting taxa related to Cd activation,thus promoting Cd uptake and accumulation.

蔬菜根系土壤硒镉含量与理化性质关系研究

以贵州省观山湖区土壤-蔬菜协同样为试材,采用调查采样方法,研究了蔬菜硒镉、土壤硒镉含量及主要理化性质,进一步了解蔬菜硒镉富集情况,明确主要土壤理化指标与土壤硒镉含量的关系,以期为富硒土壤资源的综合利用提供参考依据。结果表明:在各级理化性质分级下,土壤(0~20 cm)全硒平均含量均高于富硒土壤标准(0.4 mg·kg^(-1));采集的46件蔬菜样品镉含量均未超过食品安全国家标准《食品中污染物限量》(GB2762-2022)限量值,超标率为0%,镉的安全性较高,硒含量均未检出。土壤理化性质对硒、镉的地球化学行为有重要影响,土壤有机质、pH、碱解氮与土壤硒含量呈显著相关关系,土壤速效钾与土壤镉含量呈极显著相关关系,土壤有机质、pH、碱解氮与土壤硒之间分别呈幂函数、指数函数、线性函数关系,土壤速效钾与土壤镉含量之间呈线性函数关系。研究区存在“土壤富硒作物不富硒”的问题,究其原因是土壤总硒与有效硒的关系不明确,因此在今后的研究中探究土壤中硒的形态特征及生物有效性对富硒农产品的稳定生产具有重要意义。

土壤-植物系统中硒的生物有效性及其影响因素研究进展

硒的生物有效性是决定硒在土壤-植物系统中转运、积累的关键因素,然而目前关于该方面研究进展还缺乏系统的总结和论述。本文结合赣南富硒脐橙调查研究结果,以硒在土壤-植物系统中的运移为切入点,系统总结和论述了硒在土壤-植物系统中的氧化-还原、吸收、转运过程,探讨了土壤理化性质、微生物、施肥、农艺管理和植物生长阶段等对硒生物有效性和迁移的影响,并提出未来硒的研究热点:土壤微生物活性与硒生物地球化学循环的耦合关系;植物生长、果实品质与硒代谢相关的分子机制;结合同位素示踪技术和薄膜扩散梯度(DGT)技术原位探究硒在生物地球化学中的归趋。本综述可为土壤硒生物有效性调控、植物体系中硒的有效积累和农艺生物强化富硒措施方面的研究提供理论参考。

土壤调理剂对生姜硒镉积累和品质安全的影响

为明确土壤调理剂对重金属污染土壤上生姜的营养品质和安全性的影响及作用机制,采用生姜土壤盆栽试验,比较研究了3种土壤调理剂(硅酸钾、麦饭石、贝壳粉)对土壤硒镉有效性以及生姜硒镉积累、生长发育和营养品质的影响。试验结果表明:3种土壤调理剂均能显著提高生姜硒含量,同时显著降低镉含量。与对照(不添加土壤调理剂)相比,施用0.2%硅酸钾调理剂效果最佳,分别使生姜地上部位和姜块硒含量提高了165.01%和111.36%,镉含量降低了71.96%和65.15%;另外,施用3种土壤调理剂可显著提高姜块产量、品质及养分吸收。与对照相比,产量提高了23.93%~67.67%,可溶性糖、可溶性蛋白和姜黄素含量分别提高了2.34%~6.00%、154.72%~602.83%和11.05%~33.43%,氮、磷、钾养分含量分别提高了10.28%~14.42%、24.62%~34.87%、28.81%~29.01%;施用3种土壤调理剂还可提高姜块过氧化物酶(POD)和过氧化氢酶(CAT)活性,降低丙二醛(MDA)含量;与对照相比,3种土壤调理剂增加土壤pH 0.35~0.53个单位,土壤有效态镉含量降低了16.92%~22.76%,有效态硒含量增加了3.60%~10.99%。研究表明,施用土壤调理剂能够降低土壤有效态镉含量、活化土壤有效态硒,从而降低生姜镉含量并提高硒含量和姜块营养品质,可实现镉污染土壤安全利用,保障生姜优质安全生产。

东北典型黑土富硒区土壤与作物硒含量特征及影响因素——以海伦市为例

为探究东北典型黑土富硒区土壤–作物系统硒含量及影响因素,选择海伦市为研究区,调查分析了表层土壤的理化性质、全硒和有效硒含量,大宗农产品(水稻、大豆、玉米)可食用部分硒含量。结果表明,研究区土壤全硒含量水平相对较高,均值为0.303 mg/kg,有效硒含量均值为0.018 mg/kg,硒活化率(有效硒的占比)偏低;土壤全硒和有效硒含量都具有明显的空间分布特征,高值区主要分布在研究区的西北部和中部(永和乡、爱民乡、向荣乡和长发乡);3种大宗农作物硒含量由高到低为水稻(0.028 mg/kg)>大豆(0.014 mg/kg)>玉米(0.007 mg/kg);相关性分析表明,土壤硒含量的主要影响因素为土壤有机质、全氮、阳离子交换量和粉粒含量,高有机质含量抑制了水稻和玉米对土壤硒的吸收。本研究为研究区开发利用富硒土壤提供了从区域选择到作物类型选择的数据支撑。

高镉地质背景区土壤中镉-硒相互作用的田间试验研究

该研究系统采集广西壮族自治区靖西市那国村巴果屯地区烟草种植地烟叶、烟茎以及土壤样品,分别测定Cd、Se含量,分析Cd、Se元素在土壤未进行Cd富集与进行了富集的背景下,施加不同浓度Se肥的土壤及烟株中的含量及迁移转化。结果表明,Cd与Se之间可能存在拮抗作用,且0.14 mg/kg Se肥是较好的施加浓度,此浓度下对Cd的拮抗作用较好。通过分析典型烟草种植区不同Se肥浓度下土壤-烟叶中镉、硒含量,研究镉、硒元素在土壤-烟株中迁移转化规律,为进一步抑制烟株对镉的吸收以及硒的合理应用提供数据支撑。

典型矿区周边水田土壤Cd生物有效性研究

为遴选可有效表征农田土壤Cd生物有效性的指标,文章采集浙江某地20组稻米及其协同土壤,分析稻米Cd质量比、土壤的基本理化性质、Cd总质量比、不同浸提态Cd质量比及欧共体标准物质局(European Community Bureau of Reference,BCR)形态。结果表明:稻米Cd质量比为0.01~0.51 mg/kg,土壤Cd质量比为0.17~3.15 mg/kg,稻米Cd富集系数为0.04~1.42;土壤Cd主要以弱酸态(40.5%)和还原态(37.1%)存在,二乙烯三胺五乙酸(diethylenetriaminepentaacetic acid,DTPA)浸提土壤Cd能力最强(15.6%);基于w(CaCl_(2)-Cd)构建的三次函数建立的回归模型可解释稻米Cd 57.4%方差,w(CaCl_(2)-Cd)可以作为表征水稻土壤Cd生物有效性的指标,基于水稻土壤Cd生物有效性可提高污染风险评价的科学性。

不同氮磷肥配施生物炭对污染土壤镉有效性和青菜吸收镉的影响

本研究旨在评估不同氮磷肥配施生物炭对镉(Cd)污染农田土壤中Cd有效性的降低效果以及对作物生长的影响,为Cd污染农田的安全利用和氮磷肥料的合理选择提供科学依据。以Cd污染农田土壤为对象,采用青菜盆栽试验,对比研究了3种氮肥[硫酸铵(L)、尿素(N)和硝酸钙(X)]与2种磷肥[过磷酸钙(S)和钙镁磷肥(C)]配施生物炭(B)对土壤Cd有效性、青菜生长和吸收Cd的影响。结果表明:与不施肥的对照处理相比,氮磷肥配施显著提高青菜生物量达28.6%~65.7%,氮磷肥配施生物炭的增产效果比单施氮磷肥处理显著提高11.9%~40.0%。硝酸钙配施过磷酸钙显著提高土壤p H 0.23个单位,其余氮磷肥处理对土壤p H无显著影响,但所有氮磷肥处理土壤有效态Cd含量比对照处理降低了16.5%~38.8%,青菜Cd含量降低了5.87%~25.0%。与单施氮磷肥处理相比,氮磷肥配施生物炭处理土壤pH有不同幅度的增加,最大增幅达0.42个单位,土壤有效态Cd含量则降低了5.31%~56.3%,青菜Cd含量降低了25.5%~84.8%。研究结果证实,在Cd污染农田的安全利用过程中,合理选择和施用氮磷肥是至关重要的,这不仅可以获得最佳的经济效益,还能产生积极的环境效应。同时,配施生物炭能够进一步增强氮肥和磷肥对污染土壤中Cd活性的钝化作用。

施用硒内源调控剂对水稻吸收硒、镉和砷的影响

为探讨不同硒内源调控剂对水稻吸收硒(Se)、镉(Cd)、砷(As)及土壤中Se、Cd、As形态的影响,将多种复合调理剂添加到富硒土壤中开展盆栽试验。结果表明,施用1%或2%蒙脱复合调理剂(MT)均可获得水稻增Se降Cd的效果,2%添加量效果更佳;在高硒土(土壤Se含量1.99 mg/kg)条件下,添加钙镁磷肥+磷矿粉+活性硅(GLG)可获得水稻Se过量减毒和同时降As的双重效果;在中硒土(土壤Se含量0.83 mg/kg)条件下,添加钙镁磷肥+骨粉+活性硅(GGG),水稻的增Se降As效果最佳;而在低硒土壤(土壤Se含量0.46~0.47 mg/kg)条件下,添加钙镁磷肥+生物炭+有机菌肥+活性硅(GTJG)和添加钙镁磷肥+石灰+活性硅的增Se降As效果较好。研究表明,施加适量Se内源调控剂可实现水稻增Se、降Cd和As,同时减毒的效果。

Cellular Cd^(2+)fluxes in roots confirm increased Cd availability to rice(Oryza sativa L.)induced by soil acidifications

Soil acidifications become one of the main causes restricting the sustainable development of agriculture and causing issues of agricultural product safety.In order to explore the effect of different acidification on soil cadmium(Cd)availability,soil pot culture and hydroponic(soil potting solution extraction)were applied,and non-invasive micro-test technique(NMT)was combined.Here three different soil acidification processes were simulated,including direct acidification by adding sulfuric acid(AP1),acid rain acidification(AP2)by adding artificial simulated acid rain and excessive fertilization acidification by adding(NH_(4))_(2)SO_(4)(AP3).The results showed that for direct acidification(AP1),DTPA-Cd concentration in field soils in Liaoning(S1)and Zhejiang(S2)increased by 0.167-0.217 mg/kg and 0.181-0.346 mg/kg,respectively,compared with control group.When soil pH decreased by 0.45 units in S1,the Cd content of rice stems,leaves and roots increased by 0.48 to 6.04 mg/kg and 2.58 to 12.84mg/kg,respectively,When the pH value of soil S1 and S2 decreased by 0.20 units,the average velocity of Cd^(2+)at 200μm increased by 10.03-33.11 pmol/cm~2/sec and 21.33-52.86pmol/cm^(2)/sec,respectively,and followed the order of AP3>AP2>AP1.In summary,different acidification measures would improve the effectiveness of Cd,under the same pH reduction condition,fertilization acidification increased Cd availability most significantly.

1株芬芳镰刀菌的筛选鉴定及其提硒降镉效应

为解决农作物硒镉共积累难题,采用选择性培养基从高硒镉背景值的植物根际土壤(土壤硒总含量50.187 mg/kg,土壤镉总含量50.311 mg/kg)中分离、筛选获得了1株功能真菌,经鉴定为芬芳镰刀菌(Fusarium redolens),利用土壤模拟试验和盆栽试验测定土壤中有效硒、有效镉的变化和植物可食用部位Se含量、Cd含量,根据硒/镉富集和转运系数来评价真菌活硒抑镉的效果。土壤模拟试验结果显示,接种真菌后,活硒率与培养时间呈正相关,抑镉率与之相反;活硒率在第5天达到最高,为60.9%;抑镉率在第3天最高,为41.2%,第5天最低,为27.3%。盆栽试验结果显示,添加10^(8)cfu/mL真菌,土壤pH值比对照显著降低了0.35个单位;对碎米荠幼苗生长无不良影响,平均株高为7.4 cm,平均根长为9.6 cm,平均生物量为2.9 g,均高于对照;土壤中有效硒的含量显著提高,活硒率最高达到24.8%,而有效镉的含量显著降低,抑镉率达到24.7%;碎米荠地上/地下部分总硒含量分别增加25.6%和36.8%,总镉地上/地下部分含量分别降低32.7%和11.6%。结果表明,真菌对天然高硒镉背景值土壤具有活硒抑镉能力,且添加浓度为10^(8)cfu/mL时效果最好,有助于碎米荠的富硒降镉。

富硒土壤生物有效性及其影响因素研究

基于土地质量地球化学调查与富硒资源评价项目调查数据,分析研究区内土壤有效态硒含量及其影响因素,结合农作物调查结果,分析富硒土壤的生物有效性。结果表明,研究区土壤有效态硒含量范围在0.006~0.071 mg/kg,平均值为0.018 mg/kg;有效态硒占土壤总硒的比例为1.69%~11.49%;有效态硒含量与土壤硒全量、有机质含量呈现较好的正相关性,与土壤pH值呈弱负相关性。研究区内有发展富硒产业的潜力,其中不同农作物的富硒能力表现为油菜>茶叶>水稻。对比发现,当土壤硒含量>0.3 mg/kg时即可作为开发富硒农作物的潜力区,并通过调整土壤p H、有机质含量增加土壤中有效态硒含量,促进农作物吸收。

鸡粪生物炭的制备及其对硒镉伴生酸性土壤的改良效果研究

为探究鸡粪生物炭(JF-BC)的高效制备及其对恩施地区硒镉伴生酸性土壤改良的效果,通过优化限氧热解技术中温度、时长参数制备高吸附性能鸡粪生物炭,通过为期52 d的室内恒温恒湿土壤培养试验探究不同添加量JF-BC(未添加记作CK,2%添加量记作2%BC,4%添加量记作4%BC)对土壤理化性质的影响及动态进程。试验结果表明,热解温度700℃、热解1.5 h,制备的JF-BC产品p H最高,镉吸附性能最优。产品对于4≤pH≤8的Cd^(2+)溶液具有稳定吸附效果,吸附量为244.81~248.22 mg·g^(-1)。2%BC及4%BC处理均使得培养的土壤由酸性提升至中性或弱碱性。培养第3 d,2%BC和4%BC处理有机质、有效磷、速效钾含量较CK显著提升29.19%和56.90%、425.4%和449.09%、884.11%和1475.82%,培养过程中效果稳定持续;培养过程中2%BC处理碱解氮较CK显著提升,4%BC与CK无显著性差异。培养第52 d,4%BC土壤阳离子交换量较CK显著提升45.34%。培养过程中,2%BC及4%BC处理土壤有效镉逐渐降低,较CK最高降低32.32%,4%BC处理有效硒有所增加,较CK最高增加26.47%。JF-BC能有效改善恩施地区土壤的p H、有机质、阳离子交换量等化学性质,提升土壤磷、钾肥力,降低镉的有效性,提高硒的活化率,4%添加量改良效果更佳。但当JF-BC大量施用时,要注意氮素的补充及磷、钾素减量。此研究对改良恩施地区土壤酸化、提高硒利用率并抑制镉迁移转化提供有益探索。

5种调理剂对水田土壤中镉赋存形态的影响及其钝化效果评价

本研究旨在评估5种不同调理剂——石灰(SCⅠ)、白云石粉(SCⅡ)、牡蛎壳粉(SCⅢ)、泥炭土(SCⅣ)和硅钙镁钾肥(SCⅤ)对水田土壤中镉(Cd)污染的钝化修复效果。采用受Cd污染的弱酸性水田土壤为材料,通过盆栽模拟试验,分析了这5种调理剂对土壤pH、土壤中Cd赋存形态分布特征及生物有效性的影响。试验结果显示,供试土壤分别添加SCⅠ、SCⅡ、SCⅢ、SCⅣ、SCⅤ0.6 g/盆(2.0 kg土壤)处理60 d后,土壤pH分别提高了1.81、1.49、1.17、0.48、0.60个单位;土壤中水溶态、弱酸提取态、可还原态、可氧化态、残渣态Cd分布特征发生了不同程度的变化。具体而言,水溶态Cd分布系数分别下降了0.70%、0.54%、0.63%、0.21%和0.24%,弱酸提取态Cd分布系数分别下降了17.68%、8.39%、11.52%、18.13%和15.95%,而残渣态Cd分布系数分别上升了14.27%、5.33%、11.54%、17.70%和14.34%(P<0.05)。这些变化表明,5种调理剂均能有效降低土壤中有效态Cd含量,并增加不可利用态Cd含量(P<0.05)。SCⅠ、SCⅡ、SCⅢ、SCⅣ和SCⅤ对土壤中Cd污染的钝化效果分别为38.98%、18.42%、25.33%、39.98%和35.12%。因此,这5种调理剂钝化修复酸性水田土壤中Cd污染均显示出良好的潜力,为安全利用受Cd污染的酸性水田提供了新的技术方案,并值得进一步的田间验证和示范应用。