间套种及化学强化修复重金属污染酸性土壤——长期田间试验

为了检验重金属污染土壤间套种修复技术的长期实际应用效果,在大田条件下将东南景天(Sedum alfredii Hance)与玉米(Zea mays)间套种,并设置加入柠檬酸与EDTA混合添加剂的处理,以及单种东南景天作为对照,通过5次田间试验(约3 a),连续监测植物产量、重金属含量以及土壤重金属变化情况。结果表明,各处理土壤镉、锌随着试验的进行逐步下降,套种和套种+混合添加剂处理经过5次种植后土壤达到国家土壤环境质量二级标准,土壤镉从1.21~1.27 mg kg-1降为0.29~0.30 mg kg-1;锌从280~311 mg kg-1降为196~199 mg kg-1;但是土壤铅在试验前后没有显著变化。混合添加剂未表现出强化东南景天提取重金属的效果。东南景天重金属浓度和提取效率没有出现逐年下降的现象。单种东南景天地上部生物量在后4次试验中均较套种高,重金属的总提取量也较高。然而,间套种可生产符合饲料卫生标准的玉米籽粒,第4季达到食品卫生标准。从收获的东南景天计算得到的提取量占土壤镉下降的贡献率为32.5%~36.5%,玉米提取仅占0.47%~0.60%,其余63.0%~66.9%为淋溶等其他因素的作用;锌也相似。表明在该酸性(pH4.7)土壤上,Cd/Zn向下淋溶和东南景天提取均起重要作用。     

东南景天提取污染土壤中锌的潜力研究

通过盆栽实验研究了两种生态型东南景天提取污染土壤中锌的能力,结果表明,超积累生态型东南景天具有很强的忍耐土壤中高浓度锌、铅和镉的能力,并能从土壤中吸收和转移大量锌到地上部,超积累生态型东南景天地上部的Zn含量为7062～9558mg／kg,非超积累生态型为256～407mg／kg,超积累生态型东南景天地上部的Zn总积累是非超积累生态型的4l～62倍。矿山土壤添加稻草后,促进了超积累生态型东南景天的生长,地上部生物量显著提高,且锌含量也明显增加。种植超积累生态型东南景天后土壤乙酸铵提取态锌有上升趋势,和种植前比较,在矿山土壤和污染土壤上分别增加了4．3％和9．4％,种植超积累生态型东南景天后土壤交换态锌和有机结合态锌明显增加,残渣态锌减少,而对非生态型,种植前后土壤中锌的化学形态没有什么变化。添加菜籽饼和稻草对两种土壤中Zn的化学形态转化均没有显著性影响,其原因有待进一步研究。这些研究结果表明,超积累生态型东南景天具有较强的修复锌污染土壤的潜力。     

土壤紧实度对伴矿景天生长及镉锌吸收性的影响研究

采集黏土、壤黏土和砂质壤土,分别设置无压实、低紧实度及高紧实度3种处理,通过盆栽试验研究了土壤紧实度对Cd、Zn超积累植物伴矿景天生长和Cd、Zn吸收性的影响。结果表明,与无压实处理比较,砂质壤土、壤黏土和黏土中伴矿景天地上部生物量在低紧实度下显著下降66.8%~83.5%、59.9%~60.4%和57.9%~71.4%;高紧实度处理却显著提高了伴矿景天的根系活力(142%~241%)。高紧实度处理显著降低了壤黏土上伴矿景天地上部Cd和Zn含量,但低紧实度对砂质壤土和黏土上伴矿景天地上部Cd和Zn含量无显著影响。与无压实处理比较,低紧实度显著降低了砂质壤土、壤黏土和黏土上伴矿景天的Cd吸取量,分别下降50.4%~73.8%、61.4%~74.9%和43.4%~63.3%,Zn吸取量下降48.7%~79.5%、73.6%~79.0%和46.1%~63.5%;土壤紧实度对壤黏土上伴矿景天的镉锌吸取效率影响最明显。     

氮对超积累植物东南景天生长和镉积累的影响

通过水培试验,研究了氮素水平对超积累植物东南景天植株生长和镉吸收积累的影响。结果表明,在一定范围内供氮（4.0-16.0 mm ol/L）能明显促进东南景天的生长,随着氮素水平的升高,地上部和根系的生物量也提高,在供氮水平为16.0 mm ol/L时达到最大值,而当供氮水平≥32.0 mm ol/L时,东南景天的生长受到严重的抑制,其地上部和根系的生物量开始下降,各项根系形态的指标（包括根系长度、根系表面积、根系直径、根系体积）均有所降低。氮对东南景天体内镉积累有一定的促进作用,随着氮素用量的增加,体内镉含量逐渐升高,与生物量不同,镉含量在氮水平32.0 mm ol/L条件下达到最大。研究结果表明,适当提高营养液氮素水平,有利于东南景天的生长和镉吸收,为进一步利用东南景天修复镉污染土壤,提高修复效率提供科学依据。     

镉污染中性土壤伴矿景天修复的硫强化及其微生物效应

田间微区试验研究了施硫(S)处理对中性镉污染农田上伴矿景天镉吸取修复效率、土壤pH、有效态镉(Cd)、有效态硫以及微生物群落变化的影响。结果发现,土壤pH值随时间和硫用量的增加而显著下降,有效态镉和有效态硫随时间和硫用量的增加而显著增加。在360 g/m_²硫处理下,伴矿景天地上部镉浓度为70.9 mg/kg,较不施硫对照(38.3 mg/kg)增加85%,耕层土壤全量镉去除率为19.4%,是对照(10.5%)的1.85倍。施硫处理150天后,土壤Thiomonas和Rhodanobacter细菌相对丰度显著高于试验前土壤和对照处理。本试验结果表明,中性土壤施加适量硫磺不仅可显著提高污染土壤中镉的生物有效性,也可通过调节与硫代谢相关的功能微生物,显著增强镉的植物吸取修复效率。     

膨润土和沸石在镉污染土壤治理中的应用

采用通过盆栽试验,研究了膨润土和沸石对镉污染土壤的治理效果。结果表明,施加膨润土后不同污染程度土壤的交换态、碳酸盐结合态镉的质量分数都有所下降,铁锰氧化物结合态、有机结合态和残渣态镉的质量分数则有所上升。沸石和膨润土对轻度、中度镉污染土壤都表现出钝化作用,对重度镉污染土壤,膨润土对镉的钝化效果明显,而沸石却起到了激活镉的作用。在不同程度镉污染土壤上,膨润土可增加乌塌菜的生物量,并可抑制其对镉的吸收,降低乌塌菜植株体内镉的浓度,对乌塌菜的生长具有显著的促进作用。沸石对轻度和中度镉污染土壤均可降低乌塌菜植株体内镉的浓度,促进乌塌菜的生长并增加其生物量;对重度镉污染土壤,沸石对乌塌菜的生长影响较小,乌塌菜植株体内镉的积累显著增加。     

膨润土和沸石在镉污染土壤治理中的应用

采用通过盆栽试验,研究了膨润土和沸石对镉污染土壤的治理效果。结果表明,施加膨润土后不同污染程度土壤的交换态、碳酸盐结合态镉的质量分数都有所下降,铁锰氧化物结合态、有机结合态和残渣态镉的质量分数则有所上升。沸石和膨润土对轻度、中度镉污染土壤都表现出钝化作用,对重度镉污染土壤,膨润土对镉的钝化效果明显,而沸石却起到了激活镉的作用。在不同程度镉污染土壤上,膨润土可增加乌塌菜的生物量,并可抑制其对镉的吸收,降低乌塌菜植株体内镉的浓度,对乌塌菜的生长具有显著的促进作用。沸石对轻度和中度镉污染土壤均可降低乌塌菜植株体内镉的浓度,促进乌塌菜的生长并增加其生物量;对重度镉污染土壤,沸石对乌塌菜的生长影响较小,乌塌菜植株体内镉的积累显著增加。     

养分调控对超积累植物伴矿景天生长及锌镉吸收性的影响

采用四因素三水平正交设计温室盆栽试验研究了N、P、K三因素不同水平对Zn、Cd超积累植物伴矿景天的生长及地上部Zn、Cd吸收性的影响。结果表明,增施N肥是伴矿景天地上部干重增加的主要因素,高N配施低P(200 mg/kg N,60 mg/kg P,不施K)处理的伴矿景天地上部干重达最大值31.2 g/盆(1.5 kg土/盆),是不施肥处理的3.15倍。增施K肥是提高伴矿景天地上部重金属尤其是Cd浓度和吸收量的主要影响因子,高量K处理比不施K处理地上部Cd浓度增加28.1%;低量施P也可提高伴矿景天的Zn吸取修复效率。综合考虑伴矿景天生物量及其对Zn、Cd的吸取效率,本试验条件下低量N、P肥配施高量K肥为最佳施肥处理(N1P1K2),种植伴矿景天一季对Zn、Cd的吸取量分别为11.2 mg/kg±0.1 mg/kg和0.12 mg/kg±0.02 mg/kg。     

硫对超积累植物东南景天生长和镉累积的影响

通过营养液培养试验研究了不同硫镉水平对超积累东南景天生长和镉累积的影响。结果表明,不同处理下东南景天根、茎和叶片的生物量、镉含量、镉累积量均以叶片>茎>根,且以Cd100>Cd10,显示出东南景天对镉的超积累特性。供硫1.5~2.25 mmol/L显著提高超积累东南景天根、茎和叶片的生物量、镉含量、镉累积量及整株镉累积总量。超积累东南景天地上部分(叶片 茎)镉累积量/地下部分(根)镉累积量的比值(S/R)远大于1,表明东南景天植株体内可能存在"增硫诱导镉需求"现象,而从植物修复角度来说,利用增硫手段提高超积累东南景天生长和地上部镉的积累能力具有重要的应用价值。超积累东南景天Cd的吸收速率和转运速率随营养液中硫(S)浓度的增加而增加,二者可分别用对数方程和直线方程来描述。     

EDTA对铅污染土壤上芥菜生长及铅积累特性的影响

采用盆栽实验研究了EDTA对Pb污染土壤上芥菜生长及Pb积累特性的影响。结果表明,单独Pb处理对芥菜生物量没有明显的影响,但高Pb处理(2000mg kg-1 Pb)芥菜地上部含水量显著降低;Pb处理芥菜体内Pb含量随土壤Pb浓度的增加而明显增加,根系Pb含量高于地上部Pb含量;3mmol kg-1 EDTA处理能促进土壤Pb溶解,增加土壤有效Pb含量,影响芥菜的正常生长,芥菜地上部生物量下降,高Pb浓度处理比低Pb浓度处理更明显;EDTA处理14天芥菜地上部和根系Pb积累量都比不加EDTA的对照明显增加,地上部Pb总量增加到对照的13.1～80倍;EDTA处理芥菜地上部与根系Pb含量的比值上升,表明EDTA处理促进Pb向地上部运输,这种促进作用因土壤Pb浓度的不同而略有差异。     

Alleviation of noxious effects of cattle ranch composts on wheat seed germination by inoculation with Azospirillum spp.

Two commonly-used composts from dairy cow manure that are used to improve poor structure and fertility of desert soils have inhibitory effects on wheat seed germination, probably as a result of their high levels of humic acids. Inoculation of wheat seeds with two species of the plant growth-promoting bacteria Azospirillum brasilense Cd and A. lipoferum JA4 (separately) prior to sowing in these amended soils improved germination, similar to the natural level of germination of seeds in desert soil without compost amendment. Both compost amendments increased height of wheat seedlings in the range of 20–25%, increased shoot dry weight by 15–19%, but severely decreased (51–54% less) root dry weight. Inoculation of wheat seeds with A. brasilense Cd, but not with A. lipoferum JA4, significantly increased plant growth parameters (height, shoot and root dry weight) over control plants grown in soil-compost mixtures. This bacterial species could survive for a period of 20 days in compost humic acid solution, could increase its population when the humic acids served as the sole carbon source, and may change the composition of humic acids in which it grows. We suggest that inoculation with A. brasilense may alleviate noxious effects on germinating seeds caused by compost application by possibly transforming the composition of humic acids in the compost.     

猪粪有机肥施用对潮土速效养分含量及团聚体分布的影响

针对集约化养殖畜禽粪便无序排放产生的环境问题,采用连续2年的盆栽试验,以猪粪有机肥为研究对象,设计5个有机肥施用水平(0、6.7、13.3、26.7、40.0 g·kg~(-1)土),研究了猪粪有机肥施用对潮土有机碳、速效养分含量及土壤团聚体分布的影响,为畜禽粪便田间消纳和合理施用提供理论依据。研究结果表明,土壤中有机碳、碱解氮、速效磷和速效钾含量均随有机肥施用量的增加而呈现逐渐升高趋势,且第二年土壤中各指标增加更加明显,第二年施肥处理各速效养分含量分别比第一年高2.7%~54.0%、6.7%~34.6%、36.8%~159.5%、20.3%~35.7%;土壤有机碳含量与外源有机碳投入量之间存在着显著的线性关系,有机肥施用可以显著提高生菜产量,且具有明显的后效作用。2年试验中,土壤团聚体以0.053~0.25 mm和0.053 mm小团聚体所占比例较大,且随有机肥施用量增加呈现降低趋势,而0.25~0.5 mm和0.5 mm大团聚体含量却随有机肥施用量增加呈升高趋势,可见,施用有机肥可促进大团聚体的形成,在有机肥施加量为40.0 g·kg~(-1)土时,土壤中0.25 mm团聚体的含量最高,土壤团聚体平均重量直径(MWD)和几何平均直径(GWD)最大,土壤的团聚化作用最强,土壤结构最稳定。     

Effect of Environmentally Friendly Amendment on a Newly Found Accumulator Kalimeris integrifolia Turcz. ex DC. Phytoremediating Cd-Contaminated Soil

Pot culture experiments were conducted to study the remediation potentials of a newly found accumulator Kalimeris integrifolia Turcz. ex DC. under different cadmium (Cd) concentrations with same fertilizer level, as well as the same Cd dose under different fertilizer doses. At medium (100 g/kg) chicken manure level, Cd concentrations in roots, stems, leaves, inflorescences, and shoots of K. integrifolia grown in the soils contaminated with 2.5, 5, 10, and 25 mg/kg Cd significantly decreased (p?<?0.05) in average by 23.8%, 29.9%, 24.0%, 30.1%, and 38.6%, respectively, when compared to those of the pots without addition of chicken manure. In contrast, the medium urea amendment level (1 g/kg) showed no effect on the bioaccumulated Cd concentrations of K. integrifolia regardless of the spiked Cd doses. However, Cd extraction capacities (micrograms per pot) of K. integrifolia shoots were significantly increased (p?<?0.05) due to the gain in biomass (more than one- to twofolds) by the soil fertilizing effect of urea and chicken manure. Particularly, Cd extraction capacities (micrograms per pot) of K. integrifolia shoots amended by urea were higher than that of chicken manure. Under the condition of 25 mg/kg Cd addition, shoot biomasses of K. integrifolia were significantly increased (p?<?0.05) with the amendment of chicken manure (50, 100, and 200 g/kg) and urea (0.5, 1, and 2 g/kg). As a result, the Cd extraction capacities (micrograms per pot) were increased in treatments even though soil extractable Cd concentrations were significantly decreased (p?<?0.05) by amendment with chicken manure and maintained by urea addition. For practical application concerns, chicken manure is better used as phytostabilization amendment owing to its reducing role to extractable heavy metal in soil, and urea is better for phytoextraction.     

间作条件下螯合剂对龙葵和大叶井口边草吸收重金属的影响

用室内土培试验方法,在采自田间的Pb、Cd和As复合污染土壤中单作或间作龙葵和大叶井口边草条件下,筛选出修复Pb-Cd-As复合污染土壤较好的种植方式为间作。进一步在间作方式下,研究了外源添加不同浓度EDDS（乙二胺二琥珀酸）、NTA（氨三乙酸）和EDTA（乙二胺四乙酸）对植物吸收Pb、Cd和As的影响。结果表明,间作显著促进了龙葵地上部对Cd的吸收量和大叶井口边草地上部对As的吸收量,间作龙葵地上部吸收Cd和大叶井口边草地上部吸收As含量分别是单作龙葵和大叶井口边草的1.3倍和1.4倍,说明间作龙葵和大叶井口边草比单作更有利于修复Pb-Cd-As复合污染土壤。间作条件下,大叶井口边草对螯合剂的耐性比龙葵更强。3、6、12mmol.kg-1EDTA能极显著增加土壤中Pb、Cd有效态含量,从而促进龙葵地上部对Pb吸收和大叶井口边草地上部对Pb、Cd吸收。EDTA比NTA具有更强的提高土壤Pb、Cd有效态的能力,但对土壤As有效态促进作用与EDTA相比,NTA效果极显著,1.5、3mmol.kg-1NTA处理极显著提高土壤As有效态含量及促进龙葵和大叶井口边草地上部对As吸收。     

不同种类有机肥施用对黑土团聚体有机碳及腐殖质组成的影响

以吉林省农业科学院黑土有机培肥定位试验基地为平台,研究了不同种类有机肥(堆腐肥、鸡粪、牛粪和猪粪)施用对土壤及不同粒级团聚体中有机碳和腐殖质组成的影响。结果表明:与不施肥(CK)和单施化肥(NPK)相比,有机肥配施化肥显著(P0.05)增加了土壤有机碳、胡敏酸碳(HAC)和胡敏素碳(HUC)含量;同时,有机肥配施化肥也增加了不同粒级团聚体中有机碳和腐殖质碳含量,其中施用堆腐肥显著增加了各粒级团聚体中有机碳、HAC和HUC含量。不同种类有机肥相比,施用堆腐肥处理的土壤有机碳、HAC和HUC含量均高于其他有机肥处理,并与牛粪处理之间差异显著;施用堆腐肥和牛粪后,0.25mm粒级团聚体有机碳含量高于其他有机肥处理,且2~0.25mm粒级团聚体有机碳含量显著高于鸡粪处理;从不同粒级团聚体中腐殖质组分的分布来看,施用堆腐肥后,2~0.25mm粒级团聚体中HAC和HUC含量显著高于猪粪处理,而0.25~0.053,0.053mm粒级团聚体中HAC含量显著低于鸡粪处理。上述结果说明,有机肥配施化肥提高了土壤团聚体中有机碳和腐殖质碳含量,但不同有机肥的效应不同。     

Effects of Food Waste Compost on Soil Microbial Populations,Tomato Yield,and Tomato Quality

A pot experiment was conducted to investigate the effects of food waste compost (FW) on soil microbial population and growth, fruit yield, and quality of tomato grown in a greenhouse compared to no fertilizer (CK), chemical fertilizer (CF), decomposed chicken manure (CM), pig manure (PM), horse manure (HM), and bull manure (BM). Results show that FW treatment had the greatest numbers of bacteria, fungi, and actinomycetes in soils and shoot biomass, fruit diameter, and fruit yield of tomato, and it increased fruit yield by 12.6, 28.5, 31.0, and 40.0% when compared to HM, CF, CM, and CK, respectively. The FW treatment also improved fruit quality, with the contents of vitamin C, soluble sugar, and organic acid and the sugar/acid ratio of 22.8 mg 100 g^?1, 3.84%, 0.50%, and 7.73, respectively. Thus food waste compost can be as an alternative to chemical fertilizer and other animal manures in vegetable cultivation.     

螯合剂对大叶井口边草Pb、Cd、As吸收性影响研究

用室内土培试验方法,研究在采自田间的Pb、Cd、As、Zn和Cu复合污染土壤上种植大叶井口边草条件下,外源分别添加0、1.5、3、6、12 mmol/kg乙二胺二琥珀酸（EDDS）、氨三乙酸（NTA）和乙二胺四乙酸（EDTA）对大叶井口边草吸收Pb、Cd和As的影响。结果表明,3种螯合剂处理对大叶井口边草生物量没有显著影响,说明大叶井口边草对3种螯合剂耐性较强;6、12 mmol/kg EDTA处理能极显著提高土壤Pb有效态浓度,进而促进大叶井口边草对Pb的吸收。大叶井口边草地上部Pb吸收量最高达（47.4 ± 1.7）mg/kg,是对照的3.66倍。6、12 mmol/kg EDTA处理能极显著地提高土壤中Cd的有效性,但未促进大叶井口边草地上部对Cd吸收。6 mmol/kg EDDS和3 mmol/kg NTA显著提高了土壤中As有效态浓度,进而提高大叶井口边草地上部对As的吸收,大叶井口边草地上部吸收As最高达（276 ± 10） mg/kg。6 mmol/kg EDTA和6 mmol/kg EDDS处理下大叶井口边草提取的Pb、As量最大,分别为（317 ± 53） μg/盆和（873 ± 41）μg/盆,说明6 mmol/kg EDDS处理下大叶井口边草对复合污染土壤中As的修复具有较大的潜力。     

Effect of Organic Matter on the Release Behavior and Extractability of Copper and Cadmium in Soil

Land disposal of organic waste materials may alter the heavy-metal status of the soil by affecting metal solubility or dissociation kinetics. The aim of this investigation was to study the influences of poultry manure and pistachio compost (at the rate of 300 g kg^?1) on release behavior and extractability of copper (Cu) and cadmium (Cd) in two soils of Iran. For release studies, samples after incubation were extracted with ethylenediaminetetraacetic acid (EDTA) at pH 7.0 with shaker for periods of 5 to 2880 min. Results showed that during the reaction periods, Cu and Cd release rates were rapid at first and then became slower until equilibrium was achieved. In the two soils, extractability of Cu increased with poultry manure treatment and decreased with pistachio compost treatment as compared to the control soil, and extractability of Cd decreased with both pistachio compost and poultry manure treatments as compared to the control soil.