植物篱对石灰土坡耕地理化性质及磷素流失的影响

在三峡库区香溪河流域典型石灰土坡耕地通过修建标准径流小区,设置栀子花(灌木)和黑麦草(草本)植物篱,研究不同类型植物篱对石灰土坡耕地耕层土壤理化性质及磷素流失特征的影响。结果表明:植物篱系统可有效的增加土壤耕层细颗粒含量和减小土壤容重,从而改善土壤分形特征,增强土壤疏通性及含水量,达到增大石灰土坡耕地土壤抗蚀性指数和防治土壤养分流失的目的;2种类型植物篱在不同深度耕层、植物篱带内和带间对石灰土坡耕地理化性质及磷素流失的影响表现出一定的差异性,但总体上差异不显著;土壤耕层黏粒含量与土壤中Ca_8-P、Al-P、Fe-P、O-P和Ca_(10)-P的含量均达到了极显著正相关(r=0.772,0.805,0.603,0.682,0.738),土壤容重与土壤黏粒含量存在显著的负相关关系(r=-0.648),表明植物篱系统是通过对土壤黏粒的有效阻滞和富集,从而减小石灰性土壤容重和磷素的流失,实现改善石灰土坡耕地土壤理化性质和防治农业面源污染的效果。     

间作条件下超积累和非超积累植物对重金属镉的积累研究

通过温室盆栽试验,研究了超积累植物龙葵、非超积累植物黑麦草、苋菜分别与玉米间作条件下对重金属Cd的积累特性。结果表明,几种间作作物中地上部生物量最大的是龙葵,其次是苋菜,最小的是黑麦草,其中土壤Cd浓度为1.59 mg/kg时,龙葵地上部生物量分别是苋菜、黑麦草的2.41、10.6倍;土壤Cd浓度为1.92 mg/kg时,龙葵地上部生物量分别是苋菜、黑麦草的2.42、9.06倍,3种富集植物地上部生物量的差异达到显著水平。玉米间作条件下超积累植物龙葵各器官中Cd含量表现为叶茎籽粒根,即地上部大于根部;而苋菜中Cd含量表现为根茎叶,黑麦草中Cd含量表现为根部地上部,即非超积累植物Cd含量为根部大于地上部。土壤中Cd含量为1.59 mg/kg时,龙葵地上部Cd累积量分别为苋菜、黑麦草的28.0、59.9倍;龙葵的富集系数是苋菜、黑麦草的28.2、59.3倍,转运系数分别是苋菜、黑麦草的8.08、55.9倍。土壤中Cd含量为1.92 mg/kg时,龙葵地上部Cd累积量分别为苋菜、黑麦草的30.8、43.5倍;龙葵的富集系数分别是苋菜、黑麦草的29.4、41.4倍,转运系数分别是苋菜、黑麦草的7.98、53.6倍。综上可知,超积累植物龙葵对土壤中Cd的吸收与转运能力远远大于非超积累植物苋菜、黑麦草,龙葵是最理想的与玉米间作的Cd污染土壤修复的植物修复材料。     

喀斯特土壤与喀斯特区域土壤关系的探讨——以贵州省普定县后寨河小流域为例

当前喀斯特石漠化治理研究中出现了一个新词汇即喀斯特土壤。通过对喀斯特土壤已发表文献的研究并结合后寨河小流域内2 755个土壤剖面信息,探讨了喀斯特区域内土壤类型及其差异,对喀斯特土壤进行了定义并辨析了在纯碳酸盐岩地区喀斯特土壤与喀斯特区域土壤的区别。结果表明:后寨河流域共有石灰土、水稻土和黄壤3大土类,石灰土主要分布在海拔1 250 m以上的区域,且随着海拔的升高,分布相应增多,水稻土和黄壤主要分布于海拔1 350 m以下的区域;石灰土主要分布在流域东部峰丛洼地及中、西部山峦上,水稻土主要分布在流域东部洼地及中部河流西侧,黄壤分布无明显规律;不同土类剖面形态特征差异较大,石灰土平均土壤厚度(49.68 cm)低于水稻土(84.33 cm)和黄壤(85.54 cm),但石灰土平均石砾含量(7.94 g/kg)却远高于水稻土(4.28 g/kg)和黄壤(4.54 g/kg);石灰土、水稻土和黄壤的土壤厚度与坡度均呈负相关关系,平均坡度分别为18.92°、1.52°和3.23°。根据喀斯特的定义,喀斯特土壤应是喀斯特岩石发育形成的石灰土,而不应理解为分布在喀斯特区域的土壤,但大量文献中存在着对喀斯特土壤定义混淆的现象,辨别二者对石漠化治理具有重要意义。普定后寨河小流域土壤剖面信息也证明纯碳酸盐岩区域不仅仅有石灰土,还存在其他土壤类型,因此喀斯特区域土壤包含喀斯特土壤和非喀斯特土壤,而喀斯特土壤应特指由碳酸盐岩发育形成的石灰土。正确认知土壤的基本属性、土壤与植被的关系和土壤与母岩的关系,可以更好地辨别二者。     

不同改良剂对酸化土壤花生钙素吸收利用及生长发育的影响

为明确改良剂对酸化土壤生境及花生钙营养的调控效应,大田条件下,以不加改良剂为对照,研究石灰、硅钙肥、生物有机肥及生物炭4种土壤改良剂对酸化土壤花生植株钙吸收、利用及生育的影响。结果表明,石灰、硅钙肥及生物有机肥均能显著提高土壤全钙及有效钙含量,较对照分别增加17.0%~25.0%和116.7%~186.8%。上述3种改良剂均可显著提高植株钙的吸收与利用,其中植株钙含量和籽仁钙积累量较对照分别增加13.5%~22.3%和179.9%~478.2%,而对无经济价值器官(针壳和营养体)的钙积累量无显著影响,钙收获指数和钙利用效率较对照分别增加28.6%~78.3%和51.0~81.7%。石灰、硅钙肥及生物有机肥均能有效控制花生植株冗余生长、促进籽仁发育,营养体、针壳干重及荚果空瘪率下降,籽仁干重和荚果出仁率升高;荚果产量较对照分别增加61.3%、42.4%和49.4%。土壤钙含量(全量及有效态)、植株钙含量、籽仁钙积累量、钙利用效率及钙收获指数与荚果产量呈显著或极显著正相关。综上,石灰、硅钙肥和生物有机肥是较为理想的花生酸化土壤改良剂,而生物炭对上述各项指标无显著影响,且与对照差异不大。本研究为酸化土壤花生高产高效栽培提供了理论依据。     

四种改良剂对铜和镉复合污染土壤的田间原位修复研究

研究了石灰、磷灰石、蒙脱石和凹凸棒石对冶炼厂周边Cu、Cd污染土壤的原位修复效果。以黑麦草(Lolium perenne L.)作为田间修复植物,采用植物重金属吸收性、土壤重金属化学提取性及土壤溶液重金属浓度变化等作指标来评价修复效果,并研究了黑麦草对Cu、Cd的吸收与土壤、土壤溶液中Cu、Cd含量的相关性。结果表明,石灰高添加剂量(石灰占污染土壤耕作层质量的0.4%)处理黑麦草对重金属的富集效果最好,显著降低了重金属毒性,促进了黑麦草的生长及其对重金属的富集;石灰和磷灰石各添加剂量均显著降低了污染土壤交换态Cu含量;石灰、磷灰石和蒙脱石各添加剂量均显著提高了土壤溶液pH并显著降低了其Cu、Cd浓度。黑麦草地上部、根中Cu浓度与土壤交换态Cu及土壤溶液Cu浓度呈显著或极显著正相关关系。     

广西岩溶地区土壤类型及特性

广西石灰性土壤有三种类型Ⅰ.黑色石灰土这类土壤有明显的盐酸反应,pH7.8—8.0,硅铝分子比3.54左右,有机碳含量很高可达4—8%,团粒状结构。Ⅱ.棕色石灰土有机碳含量较黑色石灰土低,大致在3%,表土无盐酸反应,但底层近基岩处有弱盐酸反应,表土 pH6.8,心土层 pH7.2—7.8,硅、铝分子比2.70,棕色石灰土粘粒量很高,而且非淋溶作用强,因此在 B 层结构单位的表面有明显的胶膜淀积,棕色石灰土表层为核块状结构,而底土为棱柱状结构。Ⅲ.红色石灰土红棕色,弱酸性反应,表层 pH5.0—6.5,B 层 pH7.0—7.5,硅、铝分子比一般在1.74—1.84,有机质的量低于棕色石灰土约7%,而土壤结构则伏于红壤。     

烤烟根际微生物群落结构及其动态变化的研究

选择贵州省三种典型的植烟土壤———中性紫色土、黄壤和黄色石灰土为对象,研究了烤烟根际微生物群落结构及其动态变化。结果表明,在烤烟生长过程中,根际细菌的数量在团棵期最低,然后逐渐增加,现蕾期达到峰值,进而又逐渐减少;放线菌和真菌数量从团棵期到成熟期呈增长趋势。土壤类型不同,根际细菌和放线菌的数量不一样,黄壤>黄色石灰土>中性紫色土;真菌数量,中性紫色土>黄壤>黄色石灰土。烤烟根际微生物的种群多样性及其变化在不同土壤中表现也不一样,相对于黄壤和黄色石灰土,在中性紫色土中,根际微生物的优势种群数目较多,根际细菌和放线菌种群更具多样性,而且较稳定,表明其群落结构更为合理,这可能与中性紫色土上的烟草青枯病发生率较低有一定关系。     

风化煤对农田土壤重金属汞的钝化修复

风化煤钝化修复土壤主要是其活性官能团与重金属发生络合、鳌合等一系列反应,进而降低重金属在土壤中的可迁移性和生物有效性,以达到修复土壤的目的。本文系统研究了风化煤对重金属汞(Hg)的吸附特性及其对Hg在土壤中径向迁移和生物可利用性的影响。结果显示:风化煤对酸碱有一定的缓冲作用,pH对Hg的平衡吸附量影响不大,最大吸附量为8.19 mg/g,该吸附为吸热反应。风化煤对Hg的吸附作用采用Freundlich方程描述较好,为多分子层吸附,吸附动力可用拟二级速率方程描述。土柱试验中风化煤用量为1、2、4、8 g时,淋溶液中Hg含量分别下降2.62、1.66、1.10、0.70μg/g,风化煤的使用可以降低Hg从土壤向溶液的迁移。盆栽试验进一步验证了风化煤对土壤中Hg迁移的阻控作用,其中添加风化煤黄壤中移栽30 d和70 d收获的白菜叶中Hg含量较未添加风化煤黄壤中下降了0.14μg/kg和0.09μg/kg;添加风化煤和外源Hg黄壤中Hg含量是未添加风化煤黄壤的2.4倍,而收获的30、70d小白菜叶中Hg含量前者分别为0.53、0.82μg/kg,后者分别为0.35、0.48μg/kg,理论上可认为前者较后者分别下降了0.31、0.33g/kg。可见,风化煤实现了对土壤中Hg的吸附、钝化,减缓了其生物可利用性,是一种廉价高效的环境友好型钝化剂。     

不同土壤中镉对大麦和多年生黑麦草毒性阈值的研究

根据不同终点、不同农田土壤的植物毒性测试可为基于生态毒理效应的土壤镉(Cd)环境质量标准值的修订提供基础数据。以大麦和黑麦草为供试植物,研究了中国14种不同农田土壤,添加多水平外源Cd对大麦根的相对伸长量和黑麦草的发芽率、地上部生物量的影响,并结合Log-Logistic分布函数模型确定不同土壤中大麦和黑麦草Cd毒性的剂量-效应关系和毒性阈值(EC50、EC10),也测定了黑麦草地上部的Cd含量。结果表明,外源Cd含量在0～200 mg/kg时,大麦根长随土壤Cd含量的增加显著降低,EC50值为7.8～61.7 mg/kg,EC10值为0.2～5.4 mg/kg,均与土壤pH显著正相关。外源Cd含量在0～500 mg/kg时,黑麦草地上部生物量随土壤中Cd含量的增加呈先上升(5 mg/kg)后下降(≥25 mg/kg)趋势,EC50值为29.7～499.7 mg/kg,EC10值为4.4～200.0 mg/kg,二者与土壤性质均无显著相关性。与对照相比,外源Cd含量为5～25 mg/kg时,外源添加Cd对黑麦草种子发芽有促进作用,当外源Cd含量为500mg/kg时,仅有5种土壤中种子发芽率明显下降。黑麦草地上部Cd含量随着外源Cd含量(0～100mg/kg)的增加而显著升高。黑麦草地上部对土壤Cd的富集程度与土壤pH极显著负相关。黑麦草具有作为草坪草中Cd污染修复植物的潜力。大麦对土壤Cd污染胁迫比黑麦草更为敏感,总体上,pH是影响土壤Cd植物毒性的重要因素。     

浙西3类石灰岩发育土壤有机碳和团聚体稳定性的研究

选择浙西地区黑色石灰土、棕色石灰土和红色石灰土等3类石灰岩土壤,通过物理和化学性状的鉴定,研究了它们的有机碳组成和团聚体稳定性,并与当地质地同为黏土的典型红壤进行了比较。结果表明,石灰岩发育的这些土壤因同时含有较高的黏粒(350~450 g kg~(-1))、游离氧化铁(27.46~51.26 g kg~(-1))、交换性钙(8.55~25.77 cmol(+)kg~(-1)),其水稳定性团聚体(特别是大粒径水稳定性团聚体)数量和水稳定性团聚体平均重量直径明显高于红壤。由黑色石灰土至棕色石灰土到红色石灰土,随着土壤脱钙与风化程度的增强,矿物类型由伊利石、蛭石、蒙脱石的组合向高岭石、伊利石、蛭石的组合转变,碳酸钙、交换性钙、p H和阳离子交换量降低,土壤水稳定性团聚体数量趋向下降。同时,石灰岩发育土壤因风化较弱,p H较高,并含有高量的交换性钙和阳离子交换量,有利于有机胶体与无机胶体发生作用,土壤有机碳稳定性较高。水提取态有机碳占全有机碳的比例及易氧化态有机碳占全有机碳的比例均是黑色石灰土棕色石灰土红色石灰土红壤,而稳定性有机碳的比例及H/F比为黑色石灰土棕色石灰土红色石灰土红壤。模拟试验表明,由自然风化和施肥等引起的土壤酸化可引起石灰岩发育土壤水稳定性团聚体数量的下降,但酸化对红壤团聚体稳定性的影响较小。研究证实,石灰岩土壤因含有丰富的无机胶体和交换性钙,有利于有机碳的积累和水稳定性团聚体的形成,但土壤酸化可明显降低石灰岩土壤水稳定性团聚体的数量。     

不同调控措施在强酸性高硒茶园土壤中的应用研究

通过田间试验,研究了生物肥和粉煤灰、秸秆干馏液配合施用共4种不同调控措施对强酸性高硒茶园土壤上茶叶硒含量、土壤理化性质和土壤硒有效性的影响。结果表明,4种调控措施不同程度地提高了土壤中有效硒含量和茶叶硒含量,由高到低依次为：生物肥处理〉粉煤灰-秸秆干馏液-生物肥复合处理〉粉煤灰-生物肥复合处理〉秸秆干馏液-生物肥复合处理;对土壤pH值提高幅度的大小次序为：粉煤灰-秸秆干馏液-生物肥复合处理〉粉煤灰-生物肥复合处理〉生物肥处理〉秸秆干馏液-生物肥复合处理;另外,4种不同措施对改善酸化茶园土壤其他理化性质也呈现不同效果,其中秸秆干馏液-生物肥复合处理的综合效果较差。研究结果对于江苏高硒地区土壤中硒素的有效利用和加快发展富硒茶产业具有实际的参考价值和重要的指导意义。     

Alkaline coal fly ash amendments are recommended for improving rice-peanut crops

Abstract

A field experiment investigating amendments of organic material including farmyard manure, paper factory sludge and crop residues combined with fly ash, lime and chemical fertilizer in a rice-peanut cropping system was conducted during 1997–98 and 1998–99 at the Indian Institute of Technology, Kharagpur, India. The soil was an acid lateritic (Halustaf) sandy loam. For rice, an N:P:K level of 90:26.2:33.3 kg ha^?1 was supplied through the organic materials and chemical fertilizer to all the treatments except control and fly ash alone. The required quantities of organic materials were added to supply 30 kg N ha^?1 and the balance amount of N, P and K was supplied through chemical fertilizer. Amendment materials as per fertilization treatments were incorporated to individual plots 15 days before planting of rice during the rainy season. The residual effects were studied on the following peanut crop with application of N:P:K at 30:26.2:33.3 kg ha^?1 through chemical fertilizer alone in all treatments, apart from the control. An application of fly ash at 10 t ha^?1 in combination with chemical fertilizer and organic materials increased the grain yield of rice by 11% compared to chemical fertilizer alone. The residual effect of both lime and fly ash applications combined with direct application of chemical fertilizer increased peanut yields by 30% and 24%, respectively, compared to chemical fertilizer alone. Treatments with fly ash or lime increased P and K uptake in both the crops and oil content in peanut kernel compared to those without the amendments. Alkaline coal fly ash proved to be a better amendment than lime for improving productivity of an acid lateritic soil and enriching the soil with P and K.     

养护龄期对改良膨胀土无侧限抗压强度试验的影响

以湖北省宜昌市某公路膨胀土为研究对象,分别采用不同掺量的石灰、水泥、粉煤灰、风化砂对膨胀土进行改良。在经过7,14和28d标准条件养生后,进行无侧限抗压强度试验。试验结果表明,上述4种材料均能有效地提高改良膨胀土的无侧限抗压强度,在最初的14d内,水泥改良膨胀土的强度增长较为明显,后期随着养护龄期的增长,无侧限抗压强度增长速率较缓慢;石灰改良膨胀土的无侧限抗压强度值随着养护龄期的增加,一直保持近似直线形的增长趋势;粉煤灰改良膨胀土的无侧限抗压强度亦随着养护龄期的增长而呈直线增长,但其值小于石灰改良膨胀土;养护龄期对风化砂改良膨胀土的无侧限抗压强度影响很小。     

几种土壤氟吸附动力学研究

采用平衡法对我国几种土壤氟吸附的动力学过程进行了研究。结果表明,不同土壤氟吸附的动力学参数差异很大,黄壤的最大吸附量最高,棕壤最低,棕壤的平衡时间最短,石灰土的平衡时间最长。不同土壤的氟吸附动力学参数与土壤理化性质有很大相关性。供试土壤的氟吸附动力学过程用双常数方程和E lovich方程描述获得了良好的拟合效果。而一级动力学方程和二级动力学方程都不适合土壤氟吸附动力学过程的描述。不同土壤的k值和β值证明黄壤较其他土壤吸附速率大,对加入土壤中氟的缓冲性大。     

Evaluation of Cocomposted Coal Fly Ash on Dynamics of Microbial Populations and Heavy Metal Uptake

Vicia faba, in a pot experiment with sandy and clayey soils under greenhouse conditions, was checked for growth response to different amendments with coal alkaline fly ash or cocomposted fly ash mixed with lignocellulosic residues. Soil microbial populations, pH and electrical conductivity as well as heavy metal uptake by plants were monitored. At rates of five and ten percent (on a dry matter basis) in both soils, neither fly ash alone nor cocomposted fly ash exerted any negative effect. Plant biomass production was not influenced in either clayey or sandy soil. Alkaline fly ash did not promote microbial growth when applied alone to the soils. However, cocomposted fly ash generally increased bacterial and actinomycetes counts in both soils. Fungi were not affected by ash. Due to the increase of soil pH by alkaline fly ash or cocomposted fly ash, plant uptake of heavy metals was depressed in the sandy soil. Heavy metal mobility did not cause change in the clayey soil where a high buffering capacity mitigated the effects of fly ash amendments.     

施用废渣后土壤硅素释放特性及其影响因子的研究Ⅱ土壤硅素释放特性及其与pH的关系

选取5种工矿废渣进行室内模拟试验,研究不同种类工矿废渣作为硅肥施用对土壤硅素释放特性及pH的影响。结果表明:y=kxm方程可以很好地描述土壤硅素释放的动力学特征;施用废渣可显著提高水田土壤硅素释放速率,增加土壤硅素释放量,提高土壤溶液的pH值,土壤溶液pH与培养127天硅素累积释放量间呈极显著直线正相关关系;三种高炉渣(A、B、F)的施用效果明显好于粉煤灰(H)和金刚石矿渣(J),即三种高炉渣更适于作为生产硅肥的原料。     

Effect of annual applications of pelletized dolomitic lime on soil chemical properties and grass productivity

Lime in pelletized form is potentially more convenient for farmers than ground limestone, as it can be applied using conventional fertilizer‐spreading equipment. Pelletized lime is intended to maintain an optimum soil pH when applied annually at a rate of 350 kg lime/ha/yr. Interactions between lime and N fertilizer rate were examined by applying 0, 75, 150, 225 and 300 kg N/ha/yr (as calcium ammonium nitrate) in combination with 0, 175, 350 and 525 kg pelletized dolomitic lime/ha/yr over 3 yr to a permanent grassland sward used for silage production in County Down, Northern Ireland. Equal rates of ground lime, from the same source as the pelletized lime, were applied as a comparison. Effects on soil chemical properties, grass dry matter (DM) yield and herbage nutrient removal were examined. Lime maintained or slightly increased the soil pH, particularly in the top 2.5 cm of the profile, but there was no difference in the performance of pelletized lime compared to ground lime in any of the parameters measured. Lime had no significant effect on grass DM yield or grass quality; however, there was a significant (P < 0.05) reduction in yield at the first cut, particularly in year 2, when the highest lime rate (525 kg lime/ha/yr) was applied in the absence of N fertilizer. The dolomitic nature of the lime (11% Mg) resulted in significant (P < 0.001) increases in soil and herbage magnesium levels, and this could be beneficial for reducing the incidence of grass tetany in grazing animals. The P content of the herbage was also significantly higher in plots receiving lime, which suggests that lime may have enhanced the mineralization of P or stimulated root growth.     

施用废渣后土壤硅素释放特性及其影响因子的研究Ⅰ硅素释放与钙、镁、铁、铝的关系

选取5种工矿废渣进行室内模拟试验,研究不同种类工矿废渣作为硅肥施用对土壤钙、镁、铁、铝释放的影响及其与硅素释放间的关系。结果表明:y=kxm方程可以很好地描述土壤钙、镁、铁、铝释放的动力学过程,Ca释放动力学方程yCa=kCaxmCa中的参数kCa与Si释放动力学方程ySi=kSixmSi中的参数kSi表现为极显著的直线正相关关系;钙镁累积释放量之和及铁铝累积释放量之和分别与硅素累积释放量呈极显著的幂函数正相关和直线正相关关系。施用废渣可降低土壤中铁、铝的活性,甚至可增加钙、镁的含量,从而在提高土壤供硅能力的同时起到改良土壤的作用,且高炉渣A和高炉渣F的施用效果要优于高炉渣B、粉煤灰H和金刚石矿渣J,是加工硅肥的适宜原材料。     

Ash from Cereal and Rape Straw Used for Heat Production: Liming Effect and Contents of Plant Nutrients and Heavy Metals

The composition of 79 samples of straw ash from seven heating plants in Sweden was analysed with the aim of evaluating straw ash as a fertilizer and liming agent. The variation in ash composition was explained mainly by ash fraction (bottom ash vs. fly ash) and straw type (wheat, barley, rye, rape) but also by heating plant. Compared with concentrations of Zn, Pb and Cd in bottom ash, levels in fly ash were 10–90 times higher. Fly ash also contained more Cu and K compared with bottom ash. The Cd/P ratio was 0.03 in bottom ash and 0.6 g Cd/kg P in fly ash. Ash from rape straw had a higher Ca content and liming effect compared with ash from cereal straw: e.g., the liming effect of rape ash was more than three times higher than that of wheat ash. The liming effect varied between 3.5 and 44% CaO and depended mainly on the Ca content. The average P content was 1.7% (0.2–4.4%), with slightly higher concentration in rape ash than in wheat ash. The potential for using straw ash as a fertilizer and liming agent is discussed. Compared with commercial fertilizers the use of bottom ash as a P fertilizer results in a lower addition of Cd. However, the total heavy metal content of straw ash poses a potential problem.     

粉煤灰和碳酸钙对As（Ⅲ）污染土壤上小麦产量性状及麦株As含量的影响

随着经济的发展,土壤As污染问题日益严重。采用露天盆栽试验方法,研究了在As（Ⅲ）污染土壤上,添加粉煤灰和碳酸钙对小麦成熟期产量及其性状、小麦根、茎叶和籽粒As含量的影响,并探讨了粉煤灰和碳酸钙对土壤As（Ⅲ）污染修复的有效方法。结果表明,在土壤中添加100g·kg^-1的粉煤灰或1．0g·kg^-1的碳酸钙能使小麦株高、结实小穗数、穗粒数、千粒重和产量增加。与对照相比,在As（Ⅲ）污染土壤上,100g·kg^-1的粉煤灰处理显著地增加了小麦产量（P〈0．05）,极显著地降低了小麦籽粒As含量（P〈0．01）;1．0g·kg^-1的碳酸钙处理极显著地增加了小麦的穗粒数、千粒重和产量（P〈0．01）,显著地降低了根中As含量（P〈0．05）,极显著地降低了籽粒As含量（P〈0．01）。因此,在As（Ⅲ）污染土壤上,添加100g·kg^-1的粉煤灰或1．0g·kg^-1的碳酸钙能使小麦产量升高,籽粒As含量下降,有效地缓解As（Ⅲ）对小麦的毒害。