粤东凤凰山茶区土壤不同形态铅含量及其影响因素

通过对粤东凤凰山茶区12个大型茶园土壤和茶叶进行采样,采用连续提取法将茶园土壤Pb分为可交换态、碳酸盐结合态、铁锰氧化态、有机束缚态和残渣态,探讨茶园土壤Pb的5种化学形态分布与土壤理化性质、茶叶Pb含量的相关性关系。结果发现,土壤中Pb的5种化学形态分布的规律为残渣态〉铁锰氧化态〉交换态〉有机束缚态〉碳酸盐态。土壤有机质与可交换态Pb含量呈显著负相关,与碳酸盐结合态Pb呈极其显著负相关,而土壤pH值与土壤可交换态Pb呈显著负相关,与碳酸盐态Pb和有机束缚态Pb呈极其显著正相关。茶区12个茶园土壤样品的Pb生物有效性系数范围在0.029～0.113,平均值为0.061;Pb可迁移性系数范围在0.021～0.078,平均值为0.044。凤凰山茶叶Pb含量的范围在1.39～1.82 mg/kg之间,平均为1.56 mg/kg。茶叶中的Pb含量与土壤氧化物结合态Pb、有机束缚态Pb呈显著正相关,与土壤有机质呈极其显著正相关。     

粤东凤凰山茶区土壤铜、铬化学形态分布及茶叶有效性研究

采用连续化学提取法对粤东凤凰山茶区12个大型茶园共60份土壤样品中Cu和Cr的5种化学形态分布和茶叶有效性进行研究。结果发现,土壤中Cu的5种化学形态的分布规律为残渣态〉有机束缚态〉铁锰氧化态〉碳酸盐态〉交换态,而Cr的化学形态分布为残渣态〉有机束缚态〉交换态〉碳酸盐态〉铁锰氧化态。可交换态Cu和有机束缚态Cu含量与土壤有机质呈显著正相关,而土壤pH值与土壤可交换态Cu呈极显著负相关,与碳酸盐态Cu呈极显著正相关,与有机束缚态Cu和铁锰氧化态Cu呈显著正相关。可交换态Cr含量与土壤有机质呈显著正相关,而土壤pH值与土壤可交换态Cr呈极显著负相关,与碳酸盐态Cr呈极显著正相关。凤凰山茶叶Cu含量的范围在41.20～118.93mg·kg^-1之间,平均为52.92mg·kg^-1。茶叶中Cu含量与土壤可交换态Cu、有机束缚态Cu、有机质都有显著的正相关性,而与土壤pH值有显著的负相关性。茶叶Cr含量的范围在2.73～6.29mg·kg^-1之间,平均为4.13mg·kg^-1。茶叶Cr含量与土壤有机质和pH值分布呈显著正相关和显著负相关。     

珠江三角洲城郊菜地耕层土壤中Cd、Pb赋存形态及其相互关系

选取珠江三角洲典型区域城郊菜地41个耕层土壤样品,采用化学形态分级-连续提取法研究了土壤中Cd、Pb赋存形态,通过统计分析,揭示了菜地耕层土壤Cd、Pb形态分布特征及其相互关系。Cd赋存形态平均含量顺序为:铁锰氧化物结合态(32.4%)≥碳酸盐结合态(27.2%)≥交换态(21.0%)>残渣态(10.4%)>有机态(9.0%);Pb则为:残渣态(54.1%)>铁锰氧化物结合态(27.5%)>有机态(11.6%)>碳酸盐结合态(4.6%)>交换态(2.1%)。非残渣态Cd占各形态Cd总和的平均比例(89.6%)明显高于Pb(45.9%)。碳酸盐结合态Cd分别与铁锰氧化物结合态Cd、有机结合态Cd呈极显著正相关和显著正相关(前者r=0.8482,P<0.01;后者r=0.4090,P<0.05),但与残渣态Cd呈极显著负相关(r=-0.5343,P<0.01),铁锰氧化物结合态Cd和有机结合态Cd分别与残渣态Cd呈极显著正相关(前者r=0.6965,p<0.01;后者r=0.5379,P<0.01);铁锰氧化物结合态Pb与残渣态Pb呈极显著正相关(r=0.5217,P<0.01),但有机结合态Pb却与残渣态Pb呈显著负相关(r=-0.3252,P<0.05)。在散点图矩阵的基础上建立了曲线估计的回归方程,用之可预测土壤中交换态Cd、Pb的大致数量及植物有效性。     

白银市污灌区土壤-小麦系统镉赋存特征及其健康风险评价

为探明白银市有色冶炼污灌区土壤镉(Cd)形态、空间分布特征及小麦中Cd含量对人体健康的影响,采用连续分级提取法和地理信息系统(ArcGIS)空间插值方法,研究污灌区表层土壤和不同污染程度典型土壤剖面Cd赋存形态及其空间分布差异,阐明污灌区Cd在不同生育期春小麦不同器官中分布和富集特征,并利用健康风险模型计算Cd的健康风险水平并进行空间区划。结果表明,表层土壤Cd不同形态平均含量依次为碳酸盐结合态>可交换离子态>铁锰氧化物结合态>残渣态>有机结合态,占全量比例依次为碳酸盐结合态>残渣态>可交换离子态>铁锰氧化物结合态>有机结合态,其空间分布与Cd总量分布相似。Cd的五种形态均与pH呈显著负相关,与土壤有机质(SOM)呈显著正相关。除残渣态外,其他四种Cd形态和阳离子交换量(CEC)呈显著正相关。0~60 cm土壤剖面Cd形态以碳酸盐结合态和铁锰氧化物结合态为主,可交换离子态随污染程度降低而降低,残渣态随污染程度降低而增加。春小麦不同器官的Cd含量随春小麦生长总体表现为根>叶>茎>籽粒。Cd健康风险分布与土壤Cd总量、土壤可交换离子态和碳酸盐结合态Cd的空间分布一致。不同区域居民食用小麦对成人的健康风险指数(HQ)范围在1.2~5.6之间,均大于1,已存在非致癌健康风险。本研究结果为白银市土壤重金属Cd污染综合防控提供了科学依据。     

海南岛砖红壤中铅、镉的化学形态与转化

采用土培实验和连续提取.原子吸收分光光度法,研究了重金属Pb、Cd在海南岛花岗岩砖红壤中的形态组成、外源Pb、Cd污染及化学修复剂磷、钙、硫对土壤重金属形态的影响.结果表明:在供试原土壤中,重金属Pb的化学形态以结合态和残余态为主,土壤有效态Pb含量较低,其中残余态Pb>有机质结合态Pb>铁锰氧化物结合态Pb>碳酸盐结合态Pb>交换态Pb>水溶态Pb,说明土壤Pb的环境风险较低;重金属Cd的化学形态以铁锰氧化物结合态和碳酸盐结合态为主,土壤中交换态Cd含量较高,其中铁锰氧化物结合态Cd>碳酸盐结合态Cd>交换态Cd>有机结合态Cd>残余态Cd>水溶态Cd,说明土壤Cd的环境风险较高.当外源Pb、Cd污染土壤时,有铁锰结合态Pb>残余态Pb>有机态Pb>碳酸盐结合态Pb>交换态Pb>水溶态Pb,交换态Cd>铁锰氧化物结合态Cd>碳酸盐结合态Cd>残余态Cd>有机态Cd>水溶态Cd的趋势.向污染土壤施加化学改良剂过磷酸钙、硫化钠和石灰,能显著降低水溶态Pb、Cd和交换态Pb、Cd的含量,并使有机结合态Pb、碳酸盐结合态Pb和铁锰氧化物结合态Pb含量下降,但残余态Pb、碳酸盐结合态Cd、铁锰氧化物结合态Cd和有机态Cd有增加的趋势,残余态Cd的含量基本稳定.     

苏南经济快速发展区土壤Ni的形态分布影响因素——以昆山市为例

以江苏省昆山市为典型区,通过现场采样及室内分析测定,定量研究了几种因素对农田土壤Ni形态分布的影响。结果表明：（1）土壤有效态Ni含量为1.31 mg.kg-1,土壤全Ni含量为40.95 mg.kg-1,土壤Ni的活化率为3.38%。（2）土壤重金属Ni各形态含量相对大小为残渣态（36.20 mg.kg-1）〉有机质结合态（2.80 mg.kg-1）〉铁锰氧化物结合态（1.31 mg.kg-1）〉可交换态（0.54 mg.kg-1）、碳酸盐结合态（0.10 mg.kg-1）,残渣态含量明显高于其他形态,达88.16%。（3）pH值是影响可交换态Ni含量的最主要因素,达极显著负相关水平;全Ni含量是影响碳酸盐结合态Ni含量、铁锰氧化物结合态Ni含量和残渣态Ni含量的最主要因素,达极显著正相关水平;有机质含量是影响有机质结合态Ni含量的最主要因素,呈显著正相关水平。（4）〈0.01 mm粘粒含量是影响可交换态Ni含量的重要因素,有机质含量是碳酸盐结合态Ni含量的重要影响因素,pH值和有机质含量都是影响铁锰氧化物结合态Ni含量的重要因素,〈0.01 mm粘粒含量、pH值都是影响有机质结合态Ni含量的重要因素,pH值是影响残渣态Ni含量的重要因素。     

吉林西部土壤砷的形态分布及其与土壤性质的关系研究

按照生态地球化学土壤样品元素形态分析方法,将土壤无机砷分成水溶态、离子交换态、碳酸盐态、腐植酸结合态、铁锰氧化物结合态、强有机结合态和残渣态。通过对吉林西部36个表层土壤样品的测试,分析了土壤不同形态砷的分布和不同形态砷与土壤性质的关系。研究表明,洮南市不同形态砷的分布为：残渣态（65．30％）〉腐植酸结合态（17．39％）〉铁锰氧化物结合态（10．70％）〉碳酸盐态（2．23％）〉水溶态（2．17％）〉强有机结合态（1．17％）〉离子交换态（1．04％）。通榆县不同形态砷的分布为：残渣态（56．66％）〉腐植酸结合态（23．82％）〉铁锰氧化物结合态（11．08％）〉碳酸盐态（2．81％）〉水溶态（2．18％）〉离子交换态（1．98％）〉强有机结合态（1．46％）。残渣态砷是吉林西部土壤砷的主要形态。土壤水溶态砷和铁锰氧化物结合态砷与土壤pH值皆呈极显著正相关;残渣态砷与土壤有机质皆呈极显著负相关,而与土壤阳离子交换量呈极显著正相关。离子交换态砷、碳酸盐态砷、铁锰氧化物结合态砷和强有机结合态砷与土壤矿质元素的关系不大,而水溶态砷、腐植酸结合态砷和残渣态砷与土壤矿质元素的关系密切。     

吉林省西部氟病区苏打盐碱土氟的赋存形态及分布特征

为了研究吉林省西部氟病流行区农田土壤的氟形态及其分布特征,采用连续浸提法,对该区域内45个表层土壤和6个剖面土壤的氟含量进行了测定,并与土壤理化性质进行相关分析。结果表明,表层土壤全氟含量变化范围为200~450 mg/kg,平均值为266.17 mg/kg,低于全国土壤氟背景值和对照黑土,但是其生物有效性强,水溶态氟和交换态氟平均含量分别为13.73、8.49 mg/kg,均高于对照黑土。土壤剖面中,残余态氟和全氟含量呈40~60 cm0~20 cm20~40 cm;铁锰结合态氟分布较均匀;其他形态氟则随着土层加深呈降低趋势。交换态氟与其他形态氟间呈显著或极显著的正相关关系,为各形态氟相互转换的过渡形式。pH与水溶态氟、有机束缚态氟、铁锰结合态氟呈极显著或显著正相关,与交换态氟呈极显著负相关;碳酸钙、CEC分别与水溶态氟和交换态氟呈极显著正相关;另外,有效磷与交换态氟呈显著正相关;有机质与水溶态氟、铁锰结合态氟和有机束缚态氟呈显著或极显著正相关;游离氧化铁和游离氧化铝分别与交换态氟和铁锰结合态氟呈显著或极显著正相关。降低苏打盐碱土pH是降低氟生物有效性的首选方法。通过对以上土壤参数进行分析,为今后降低该区域土壤中氟的生物有效性提供技术支持。     

河北主要土壤中Cd和Pb的形态分布及其影响因素

采用网室盆栽试验和大田取样 ,运用连续提取方法 ,研究了河北平原潮土和潮褐土两种土壤中Cd、Pb的化学形态特征及与其影响因素的关系。结果表明 :随着Cd、Pb污染程度的增加 ,其交换态有增加趋势。当高浓度重金属污染土壤时 ,Cd(潮土 >1mgkg- 1、潮褐土 >5mgkg- 1)主要以交换态存在 ,并表现为 :交换态 >碳酸盐结合态 >铁锰氧化物结合态 >有机结合态 >残留态 ;Pb主要以碳酸盐结合态和铁锰氧化物结合态存在。在低浓度重金属污染的土壤中 ,Cd (潮土 <1mgkg- 1、潮褐土 <5mgkg- 1)的残留态、有机结合态成倍增加 ,甚至超过交换态 ,表现为 :残留态 >碳酸盐结合态 >有机结合态 >交换态 >铁锰氧化物结合态 ;Pb主要以铁锰氧化物结合态和残留态存在。Cd、Pb在土壤中的分布与土壤的pH值 ,有机质含量密切相关。     

水稻对苏打盐碱土锌形态转化的驱动作用研究

为了揭示种稻对苏打盐碱土中Zn形态转化的驱动作用及其机理,采用Tessier连续提取法研究了松嫩平原不同种稻年限苏打盐碱地水田土壤中不同形态Zn含量及其在剖面中的分布特征。结果表明:盐碱地种稻改良后,可显著提高土壤剖面各层次中的有效Zn、交换态Zn及有机结合态Zn等生物有效态Zn的含量,降低碳酸盐结合态Zn、氧化物结合态Zn及残渣态Zn等非生物有效态Zn的含量。这种作用在种稻后的第1年表现的最为显著,第5年之后进入平缓上升阶段;种稻对有效Zn、交换态Zn及有机结合态Zn等生物有效态Zn含量提升的促进作用是随剖面层次的加深而减弱的。相关分析表明,交换态Zn和有机结合态Zn分别与pH呈显著负相关关系,而与有机质含量呈显著正相关关系;碳酸盐结合态锌和氧化物结合态锌与pH呈显著正相关;与有机质含量呈显著负相关关系。说明盐碱土种稻改良后,土壤pH降低和有机碳含量的提升是驱动不同形态Zn转化的主要因素。     

凤凰单枞茶树吸收土壤铬和锰的规律研究

[目的]探究凤凰单枞茶树对土壤中铬和锰的吸收规律,为综合防治茶园土壤Cr和Mn污染提供科学依据。[方法]对粤东揭阳市揭东县宝山茶园凤凰单枞茶树和土壤进行采样,运用原子吸收分光光度计法测定茶叶、茶茎和茶根中Cr和Mn的含量,并采用乙酸提取法和原子吸收分光光度计法测定土壤样品中酸可提取态Cr和Mn的含量。[结果]茶树各器官Cr含量由高到低分布情况依次为:茶根>茶茎>茶叶;而Mn含量分布情况依次为:茶叶>茶茎>茶根。茶叶中Cr和Mn含量与土壤中酸可提取态Cr和Mn呈显著正相关性,茶茎中Cr含量与土壤中酸可提取态Cr也呈显著正相关性;茶叶、茶茎和茶根中的Cr含量均与土壤中有机质含量呈显著正相关性,茶根中的Mn含量与土壤pH值呈显著负相关性,茶叶中的Mn与土壤有机质呈显著正相关性。[结论]通过调节土壤酸可溶解态Cr和Mn,土壤pH值和有机质含量,从而控制茶树吸收Cr和Mn的量,可以达到防治茶叶重金属污染,提高茶叶质量的目的。     

Tea Plantation–Induced Activation of Soil Heavy Metals

Abstract

The accumulation of heavy metals in tea leaves is of concern because of its impact on tea quality. This study characterized long‐term changes of soil properties and heavy‐metal fractions in tea gardens and their effect on the uptake of metals from soils by the plants. Soil and tea leaf samples were collected from five plantations with a history of 2–70 years in Jinghua, Zhejiang Province, southeast China. The six chemical fractions (water‐soluble, exchangeable, carbonate‐bound, organic‐matterbound, oxide‐bound, and residual forms) of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), manganese (Mn), lead (Pb), and zinc (Zn) in the soils were characterized. Dissolved organic‐matter accumulation in the soils and effects of low‐molecular‐weight organic acids on solubility of soil heavy metals were also tested. Long‐term tea plantation use resulted in accumulation of dissolved organic matter, decrease of soil pH, and elevation of water‐soluble and exchangeable metal fractions, thereby increasing metal contents in leaves. The influence was more significant when soil pH was less than 4.4. The results indicated that both acidification and accumulation of dissolved organic matter induced by tea plantations were also important causes of increased accumulation of the metals in the tea leaves. This was particularly true for the soils polluted with low concentration of heavy metals, because availability of the metals in these soils was mainly controlled by pH and dissolved organic matter.     

青岛崂山茶园土壤微量元素有效量及其影响因素研究

青岛市崂山茶种植区土壤调查研究表明,茶园土壤中6种主要微量元素(Zn、Cu、B、Mn、Fe、Mo)的有效量多大于其缺素临界值,有效态铜、锌、锰含量均处于高水平,钼中等,硼较低。统计分析表明,土壤中Zn、B、Mn等元素全量与有效量间具显著正相关性,Fe呈显著负相关性,说明全量并不是有效量的完全控制因素;pH值与有效态Zn、Cu、B、Fe和Mo均有一定的负相关关系,表明土壤酸性增强(酸化)会增加这类元素的生物有效性;有机质含量与有效态Zn、Cu、B、Fe和Mo呈正相关性,说明有机质较高有利于土壤元素活化。     

江苏省典型茶园土壤酸化趋势及其制约因素研究

茶园土壤酸化日趋严重已成为当前茶叶生产中的突出问题。为制定茶园土壤酸化的控制对策,本文采用定位监测的方法,分析了江苏省茶园土壤酸化现状和土壤pH降低速率的动态变化及其与酸雨、土壤性质的关系。2008—2010年间江苏省21个典型茶场调查结果显示:所有被调查的茶园土壤pH值均低于茶树生长最适值5.5,其中pH值低于4.0的茶园比例达42.8%。2003—2010年间,江苏省茶园土壤pH降低速率呈现先逐年增大后减小的变化规律,期间2007年土壤pH降低速率达到最大。茶园土壤酸化及其动态变化受研究区域酸雨强度和频率的影响,同时土壤pH降低速率与土壤有机质、交换性盐基总量呈极显著的负相关,与土壤阳离子交换量(CEC)、黏粒含量存在显著的负相关关系。     

武夷山丘陵茶园红壤土壤可蚀性近似计算初探

土壤可蚀性是土壤侵蚀内动力因素,反映土壤对外营力作用的敏感性,但其定量化计算普遍存在参数复杂、计算过程繁琐的问题。为寻找近似计算K值的途径,分别使用沉降法及丘林法对武夷山市丘陵地区32组茶园红壤机械组成与有机质进行测定,对比M层(耕作层)、N层(非耕作层)机械组成差异,以EPIC方程计算茶园红壤K值并分析变化规律,建立了并优化单个粒径数据与K值的近似方程。结果发现:(1)丘陵茶园红壤以砂粒及黏粒为主,M层pH值更低,N层K值高于M层,更易被侵蚀;(2)砂粒与K值有强负相关关系,粉粒与黏粒与K值有强正相关关系,有机碳与K值相关关系弱;(3)通过线性、幂函数、二次多项式拟合形式,砂粒、粉粒与K值可建立拟合效果良好的近似方程,二次多项式对砂粒拟合效果较好,幂函数对粉粒拟合效果较好,黏粒拟合效果差。将两种方程联立,结合多元线性回归分析赋予权重,并通过平均绝对偏差多次迭代修正的方法,可降低拟合误差。     

贵州省开阳茶园土壤养分状况与肥力质量评价

为明确贵州省开阳县茶园土壤养分状况,为优质茶叶生产提供参考,对贵州省开阳县茶园土壤进行了调查,分析了158个土壤样品的养分含量及养分间的相关性,并采用主成分分析法和模糊数学隶属度函数模型,通过计算土壤肥力综合指标值(IFI)对土壤养分状况进行综合评价。结果表明:贵州省开阳茶园土壤p H偏酸,有机质、全氮和碱解氮含量较为丰富;但全磷、速效磷、全钾和速效钾含量缺乏所占比例较大,分别仅有16.46%、14.56%、20.89%和12.66%的土壤样品达到优质高产茶园标准。开阳茶园土壤IFI值平均为0.59,属于中等以上土壤肥力茶园所占的比例为61.40%,茶园土壤肥力质量总体水平属于良好,但土壤偏酸,速效磷和速效钾的含量相对偏低,应重点改酸和增施磷钾肥。     

Retention of copper, cadmium and zinc in soil and its textural fractions influenced by long-term field management

The present study investigated the impact of long‐term soil management on the metal retention capacity of soil. We examined the sorption behaviour of Cu, Cd and Zn in soils and in the various particle‐size fractions of these soils, which had been amended with farmyard manure, mineral fertilizers or were fallow for 38 years in a long‐term field experiment. The soils investigated contained different amounts and origins of organic matter and differed in soil pH, but the mineral phase showed less response to the different soil managements. Batch adsorption and desorption experiments as well as a sequential fractionation schema, which defines seven geochemical fractions, were used to investigate the retention properties of soil. Sequential extraction was conducted with original as well as with metal‐spiked soils. Results showed that amounts of Cu, Cd and Zn retained differed by a factor of more than 3 among the treatments in the long‐term field experiment, when a massive concentration of metal was added to soil. An increased sorption on smaller particle size fractions occurred (clay ≫ silt > fine sand ≥ coarse sand) due to the larger surface area as well as the greater carbon content in the smaller fractions. Soil sorption behaviour in another long‐term field experiment was estimated based on the present particle‐sorption data. Differences in the sorption behaviour were related to differences in soil mineralogy and amounts of Fe‐ and Mn‐oxides. Fractionation of the original and the metal‐spiked soil underlined the contribution of organic matter to sorption capacity (sequence: Cu ≫ Cd > Zn). Different organic matter contents and a different soil pH considerably changed the amounts of metals in the defined geochemical fractions. Freshly added Cu, Cd and Zn ions were found mainly in more mobile fractions. In contrast, metals in non‐spiked soils appeared in less‐mobile fractions reflecting their long‐term sorption behaviour.     

Relationship Between Extractable Metals in Acid Soils and Metals Taken Up by Tea Plants

Abstract

The accumulation of heavy metals in plants is related to concentrations andchemical fractions of the metals in soils. Understanding chemical fractions and availabilities of the metals in soils is necessary for management of the soils. In this study, the concentrations of copper (Cu), cadmium (Cd), lead (Pb), and zinc (Zn) in tea leaves were compared with the total and extractable contents of these heavy metals in 32 surface soil samples collected from different tea plantations in Zhejiang province, China. The five chemical fractions (exchangeable, carbonate‐bound, organic matter‐bound, oxides‐bound, and residual forms) of the metals in the soils were characterized. Five different extraction methods were also used to extract soil labile metals. Total heavy metal contents of the soils ranged from 17.0 to 84.0 mgCukg^?1, 0.03 to 1.09 mg Cd kg^?1, 3.43 to 31.2 mg Pb kg^?1, and 31.0 to 132.0 mg Zn kg^?1. The concentrations of exchangeable and carbonate‐bound fractions of the metals depended mainly on the pH, and those of organic matter‐bound, oxides‐bound, and residual forms of the metals were clearly controlled by their total concentrations in the soils. Extractable fractions may be preferable to total metal content as a predictor of bioconcentrations of the metals in both old and mature tea leaves. The metals in the tea leaves appeared to be mostly from the exchangeable fractions. The amount of available metals extracted by 0.01 mol L^?1 CaCl₂, NH₄OAc, and DTPA‐TEA is appropriate extractants for the prediction of metals uptake into tea plants. The results indicate that long‐term plantation of tea can cause sol acidification and elevated concentrations of bioavailable heavy metals in the soil and, hence, aggravate the risk of heavy metals to tea plants.