树木年轮化学元素含量分析的正确取样方法

实测表明，在同一年轮中：Ｃｄ，Ｐｂ，Ｚｎ，Ｍｎ和Ｃｕ等重金属元素在早材中的含量高于晚材；在年轮平面的不同方位含量也不同，呈角分布。为了能得到年轮元素含量对于时间和方位的平均值；必须覆盖整个年轮环域均匀地雕刻一薄层木质进行取样。     

太原市耕作土壤和作物中Cd的污染分析

在调查监测的基础上,对太原市三县（区）耕作土壤和农作物中Ｃｄ元素的含量及污染程度进行了分析评价。研究了耕作土壤与农作物中金属元素Ｃｄ的相互关系。结果表明,该地区耕作土壤和农作物中Ｃｄ元素严重超标。经相关性检验,土壤中Ｃｄ含量与农作物中Ｃｄ含量密切相关,其相关性均达显著水平,说明该区农作物的Ｃｄ污染主要来自于土壤的Ｃｄ污染。     

广东红壤中稀土元素的含量及分布特征

对广东8种不同母质来源的土壤样品中的稀土元素含量及分布特征进行了研究，结果表明，除了砂岩外，其余母质上发育的红壤稀土元素总量都低于中国土壤平均含量，其中又以Q2粉砂岩、Q1砂岩、老红沙3种母质的红壤表现最为突出。除了铥、镥和铈外，11种稀土元素的平均含量都低于中国土壤平均含量。广东红壤轻组镧系元素（LREE）和重组镧系元素（HREE）的比值较大，其平均值为15．6。各母质土壤中的Eu表现出明显的负异常，δEu值与中国土壤平均值相接近；而Ce表现出明显的正异常，δCe平均值为1．48，明显高于中国土壤平均值。偶数稀土元素含量均明显高出奇数稀上元素。广东红壤中稀土元素的含量分布受母质、成土过程和外部环境等因素的影响。     

黄骅市土壤重金属空间变异特征及污染评价

为研究工业和经济高速发展对环渤海滨海生态脆弱区土壤质量的影响,以黄骅市为研究区,利用地统计学方法对黄骅市表层土壤中的Pb,Hg,Cd,Cr,As,Cu,Zn,Ni共8种重金属空间分布特点和污染状况进行了分析。结果表明:（1）Pb,Cd,Cu元素样点平均含量超过河北省土壤背景值,其他元素含量平均值均未超过,所有元素含量平均值都在国家土壤质量二级标准的范围内。（2）根据变异函数拟合发现,Pb,Hg,Cd,Cr,As,Cu共6种元素拟合于指数模型,Zn,Ni两种元素拟合于球状模型;Pb,Cd,Zn基底效应值为25%～75%,空间自相关程度一般,其空间分布格局受到一定外界干扰。其他元素基底效应值均在25%以下,空间自相关性比较强,空间分布格局受外部影响相对较小。（3）根据克里格内插预测发现,Pb,Cd,Cu整体含量高,区域离散分布;Cr,Zn,Ni整体含量低,连续集中分布;As元素成岛状分布,分布集中于几个区域;Hg成散点状分布于黄骅全县。（4）通过计算内梅罗污染指数可知,黄骅市土壤内梅罗污染指数大部分处于1.0～2.0,属于轻度污染状态;吕桥镇中部和齐家务乡西部污染指数最高,属于污染最严重的地区。工业生产和地质环境是影响土壤重金属元素空间分布的主要原因。     

贵州省典型土壤中稀土元素含量及分布特征

本文对贵州省六个主要土类有代表性的典型土壤６８个剖面,２０４个土样中的稀土含量及分布进行研究。结果表明：贵州省典型土壤中稀土元素总量（２６４．４４μｇ／ｇ）高于全国土壤平均含量（１９５．７μｇ／ｇ）,各土类稀土元素的丰度都遵守Ｏｄｄｏ－Ｈａｒｋｉｎｓ法则,Ｃｅ富集明显,贵州典型土壤中轻稀土元素含量（１９９．０１μｇ／ｇ）亦高于全国土壤,属典型的轻稀土土壤类型;石灰土中稀土各元素含量大于其它土类。同     

内蒙古地区A、C层土壤中金属元素含量比值的影响因素及其空间结构分析

本研究对内蒙古地区３４９个样点Ａ、Ｃ层土壤中１０种金属元素含量的比值进行了分析．总体而言，金属元素在内蒙古地区表层土壤中有富集的趋势，但它们在Ａ、Ｃ层土壤中含量的比值具有较大方差；偏相关分析的结果表明，土壤有机质含量、ｐＨ值和粘粒含量没有对上述比值产生显著的影响；同时，通过半方差函数的计算和空间插值对上述比值的空间结构特征进行了讨论．结果显示，研究元素在内蒙古土壤中的纵向分布没有表现出明显的空间结构，多数元素在Ａ、Ｃ层土壤中含量比值的半方差函数表现为纯块金效应．因此，内蒙古地区金属元素沿土壤剖面分布特征主要影响因素的空间变异尺度可能在本研究的最小采样尺度（大约２０ｋｍ）以下．     

开封市土壤地球化学元素分布特征研究

土壤的元素构成及含量与土壤质量有密切的联系,土壤地球化学元素的分布特征研究对农业区域发展规划具有重要的参考价值。该文以开封市土壤为研究对象探讨了28种土壤地球化学元素的分布状况。研究采用统计分析、地统计分析、综合比较等方法,找出了研究区内土壤地球化学元素的分布特征。结果表明,开封市表层土壤多数地球化学元素空间自相关性强;水平方向上,不同质地的土壤元素含量差异明显;纵向上,表层土壤地球化学元素区域富集系数普遍偏低,而N、P、K、Corg及重金属元素受人类活动的影响较大表现出局部富集;开封表层土壤多数地球化学元素含量平均值比河南省和全国背景值低,而CaO、MgO、Corg、Na2O、Al2O3含量平均值明显比全国背景值高。     

松嫩平原产油区农田土壤重金属含量及污染风险评价

  目的  为探明松嫩平原石油开采及石化工业活动区周边农田土壤重金属污染分布及风险状况。  方法  在大庆市让胡路区选择代表性农田采集96份土壤样品,测定重金属（Cd、Hg、Ni、Pb、Cu、Zn、Cr、As）含量;在利用地统计学克里金插值法分析重金属含量空间分布特征的基础上,采用地积累指数法和潜在生态危害指数法对该地区农田土壤重金属污染状况及其生态风险进行评价。  结果  该区土壤中Cd和Ni的含量分别为土壤背景值的1.39倍和1.27倍。在对各样点Pb、Zn、Cu和Cr 4种元素含量分析中,均出现不同程度的高于土壤背景值的样点。重金属Cd的地积累指数平均值为0.11,达到轻度~中度污染水平。研究区土壤重金属潜在生态危害风险指数（RI）平均值为84.84,从大到小为Cd > Hg > Ni > As > Pb > Cu > Zn > Cr,其中Cd的RI值最大为190.23,达到中等生态危害范围。研究区农田土壤重金属含量在空间分布上表现为:Cd、Zn和Pb含量高值区出现在中部地区,其它重金属元素含量高值区分布比较零散。  结论  研究区域内,8种重金属含量的平均值均低于风险筛选值,Cd和Ni两种重金属平均含量超出了背景值,从地积累指数来看,Cd污染等级为1级,其它7种元素均处于无污染水平。从潜在生态风险分析可知,该区域污染程度属于轻度生态危害范围。     

长江三角洲典型地区工业企业的分布对土壤重金属污染的影响

以长江三角洲地区近年来经济发展较快的张家港市为例,在密集的大田采样和大田与企业周围采样结合的基础上,评价了该市土壤Cd、Hg、Pb污染状况;讨论了两种不同采样方式对土壤污染状况评价的影响;用土壤表层与底层重金属含量的比值（后简称元素比值）为指标讨论了不同类型企业对周围土壤重金属积累的影响.总的来看,张家港市土壤重金属整体平均值与环境背景值接近,明显低于国家环境质量（GB 15618-1995）二级标准和中国绿色食品生产基地环境土壤污染限值（NY/T391-2000）.但存在少数样点超标和超限现象,空间上有小面积高含量土壤分布,且主要局限于企业周围的小范围内.采样方式对土壤污染的评价有明显的影响,对Cd和Pb而言,大田采样方式下他们的含量要明显低于两种方式结合的情况下（p＜0.05）,而Hg元素则相反,当大田采样与企业周围采样相结合可使得土壤中Hg元素高含量的分布面积明显增大.绝大部分企业周围土壤样品的元素比值要明显高于大田采集的土壤.除冶金类企业有着明显的Pb单一聚集外,化工、电子类企业往往导致了多个元素的积累,企业对周围土壤存在复合污染的可能性.这些结果为该市或类似地区的环境质量调查和评价、环境治理提供了重要的基础资料和决策依据.     

中国主要类型土壤若干重金属临界含量和环境容量区域分异的影响

本文通过八年研究结果，分析了土壤区域，地带性土壤类型分布，土壤ｐＨ，碳酸盐，有机质等因素对Ｃｄ，Ｃｕ，Ｐｂ，Ａｓ四种元素土壤临界含量和环境容量区域分异的影响，其中以土壤ｐＨ和土壤类型分布是主要影响因素。Ｃｄ和Ｃｕ的土壤临界含量，环境容量和土壤ｐＨ间呈负相关性，并随土壤类型由北到南的分布而减小。土壤Ａｓ的临界含量和环境容量随土壤ｐＨ增大和土壤类别由南到北的分布而增大。但它们之间无相关性。     

旱地土壤微生物磷测定方法研究

介绍了国外关于土壤微生物磷测定方法的研究进展 ,讨论了常用的几种方法所存在的问题 ,介绍了主要操作过程要求。对我国 5种主要母质类型的土壤 (pH 3 .3～ 7.4,1molL- 1KCl)的对比研究表明 ,我国土壤采用氯仿熏蒸、0 .5molL- 1NaHCO3在 1∶2 0土水比提取测定无机磷 (Pi)、并以同时测得的培养土壤微生物的磷的回收率作为计算常数得到的结果最佳。测定的大多数南方土壤的微生物磷占土壤全磷的比例小于 1 .5 % ,微生物碳磷比值大于 3 0∶1 ,反映南方土壤磷的生物活性较低 ,土壤微生物对磷的作物供应调节能力不强。     

Microbial C,N, and P relationships in moisture‐stressed soils of Potohar,Pakistan

In 11 rain‐fed arable soils of the Potohar plateau, Pakistan, the amounts of microbial‐biomass C (C_mic), biomass N (N_mic), and biomass P (P_mic) were analyzed in relation to the element‐specific total storage compartment, i.e., soil C_org, N_t, and P_t. The effects of climatic conditions and soil physico‐chemical properties on these relationships were highlighted with special respect to crop yield levels. Average contents of soil C_org, N_t, and P_t were 3.9, 0.32, and 0.61 mg (g soil)^–1, respectively. Less than 1% of P_t was extractable with 0.5 M NaHCO₃. Mean contents of C_mic, N_mic, and P_mic were 118.4, 12.0, and 3.9 µg (g soil)^–1. Values of C_mic, N_mic, P_mic, soil C_org, and N_t were all highly significantly interrelated. The mean crop yield level was closely connected with all soil organic matter– and microbial biomass–related properties, but showed also some influence by the amount of precipitation from September to June. Also the fraction of NaHCO₃‐extractable P was closely related to soil organic matter, soil microbial biomass, and crop yield level. This reveals the overwhelming importance of biological processes for P turnover in alkaline soils.     

陕西地区土壤中的硒

硒是人和动物体必需的微量元素之一,早已证明,土壤和饲草中过量的硒会导致牲畜中毒而罹患“碱质病”和“盲跚症”,而土壤和饲草硒含量过低则会引起牲畜白肌病等多种缺硒病^[9]。近年来国外又有资料报道食物和饮水中的低硒容易使人体产生癌症、心血管病、关节炎、婴幼儿碎死症等多种疾病^[6]。鉴于在土壤一植物一动物和人的生态系统中,土壤是最基本的因素,因此对土壤硒的研究在许多国家早已受到人们的重视。国内对土壤硒的研究,始于七十年代对人体地方性疾病的研究,现已证实,地方性克山病、大骨节病的发生与环境和机体缺乏硒有密切关系^[1,3,11]。     

Hot water extractable C and N in relation to microbiological properties of soils under beech forests

Hot water extraction is sometimes recommended as an easy method to estimate the readily mineralizable fractions of total C (C_t) and total N (N_t) in arable soils. However, the usefulness of this method for forest soils has not been adequately studied. The objectives of this study were to relate the hot water extractable C (C_hw) and N (N_hw) to microbiological and chemical properties of the forest soils under beech (Fagus sylvatica L.) stands and to test the ability of near infrared spectroscopy (NIRS) to predict chemical and microbial properties of these soils. Soils differing in humus type, soil type and soil texture were collected from five locations and five depths. In all soils the amount of C_hw was higher than the microbial biomass C (C_mic) indicating that a considerable part of C_hw was of non-microbial origin. The amount of C_hw in mineral soil correlated significantly (r =–0.30–0.53) with C_mic, basal respiration (BAS) and C_t/N_t ratio but was not related to C_mic/C_t ratio. The amount of N_hw was correlated with C_mic, BAS, C_mic/C_t ratio, and C_t/N_t ratio (r =–0.59–0.78). However, C_t and N_t values showed better relationships (r =–0.42–0.88) with all the parameters, indicating no advantage in using C_hw and N_hw in forest soils. NIRS predicted satisfactorily C_t, N_t, C_hw, N_hw, C_mic, C_mic/C_t ratio and BAS in the mineral soils [the regression coefficients (a) of linear regression (measured against predicted values) ranged from 0.84 to 1.17 and the correlation coefficients (r) ranged from 0.86 to 0.94] indicating the applicability of NIRS to estimate these properties.     

ENZYME ACTIVITIES AND OXYGEN UPTAKES OF SOILS UNDER PASTURE IN TEMPERATURE AND RAINFALL SEQUENCES

Some glycoside hydrolase activities, dehydrogenase activities, and oxygen uptakes were studied in New Zealand topsoils under pasture, arranged in two zonal soil sequences: one in which mean annual temperature varied (5 soils), and another in which mean annual rainfall varied (7 soils). Differences in other site factors were small. All the biochemical activities were negatively, but not usually significantly, correlated with mean annual temperature. Activities did not appear to be influenced by differences in the proportions of grasses and legumes (mainly clovers) or in the clay contents at the different sites. Activities of glycoside hydrolases (a) without added substrate and (b) with added starch were significantly correlated with mean annual rainfall, and with soil moisture and organic C contents; activities of (c) enzymes hydrolysing sucrose were significantly correlated only with soil organic C contents. The ratios of (c) to (b) declined significantly with increasing mean annual rainfall. Dehydrogenase activities were highest in winter samples and significantly correlated with both soil moisture content and pH. Oxygen uptakes were significantly correlated with numbers of viable bacteria in soils of the rainfall sequence although they were not significantly correlated with annual rainfall nor with soil organic C contents. Oxygen uptakes and dehydrogenase activities were not significantly interrelated. Results were compared with previous studies of grassland soils.     

土壤吸附砷酸盐动力学的初步研究

本研究目的是了解陕西省的几种土壤吸附和解吸附砷酸盐的速率和过程,以及其吸附能量。Kuo和Lotse导出的双常数速率公式拟合试验资料优于一级、二级、三级反应公式,抛物线扩散和Elovich公式等五个公式。用双常数速率公式(C=k·C₀·t^1/m)分两段拟合能进一步提高拟合优度。根据Arrhenius公式计算出的吸附活化能是0.70—3.40千卡/克分子。低的活化能表明,供试土壤对砷酸盐的吸附作用是一种完全不同于真溶液条件化学反应的物理学过程。土壤吸附和解吸附砷酸盐的速度和容量受作用时间、温度、溶液∶土壤比率,加入的砷量和浓度,以及土壤特性的影响。粘土的吸附反应常数(k),吸附量比沙壤土大。而沙壤土有高的解吸附反应速度常数(k_-1^'),砷酸盐容易被解吸附而释放出来。     

植物篱枝叶有机碳分解研究

研究植物篱枝叶的分解和养分矿化过程对该模式下养分的有效利用具有重要意义。在金沙江干热河谷坡耕地上利用分解袋法对新银合欢、山蚂蝗等 6个植物篱树种枝叶的分解进行了研究 ,结果显示山蚂蝗和新银合欢分解最快 ,前 2个星期有机碳分解了48 6 %和 5 0 0 % ;山毛豆和云南合欢次之 ,前 4星期有机碳累积分解量为 5 1 5 %和 45 6 % ;圣诞树和黑荆树分解最慢 ;将枝叶埋入土壤中比覆盖地表分解快。有机碳的分解规律可以用单指数模型Ct=C0 (1 e kt)和双指数模型Ct=C0 1 (1 e k1t) C0 2 (1 e k2 t)拟合 (式中 ,Ct 为有机碳累积分解量占全碳百分数 ,C0 、C0 1 和C0 2 分别为易分解有机碳和难分解有机碳百分数 ,k和k1分别为易分解有机碳分解常数 ,k2 为难分解有机碳分解常数 ) ,双指数模型更具合理性。研究表明有机碳的累积分解量与枝叶初始C/N比呈负相关 ,枝叶分解速度可用有机碳 (或易分解有机碳 )半减期来衡量。     

SOLUBILITY AND SORPTION OF CADMIUM IN SOILS AMENDED WITH SEWAGE SLUDGE

The mechanisms governing the retention and release of Cd in two soils, a loam and a loamy sand, pretreated with anaerobically digested sewage sludges or with chemical fertilizers, were studied using batch equilibration in 0.05 m Ca(NO₃)₂ solution containing up to 6 μg Cd/ml. Adsorption rather than precipitation as Cd₃(PO₄)₂ limited solution Cd²⁺ concentration. With the addition of 50 μg Cd/g, however, precipitation as CdCO₃ was likely at pH 7.6. Cadmium adsorption increased with increasing soil pH. The differences in Cd adsorption between different soil treatments were attributed mainly to the soil pH (6.9 to 7.9) induced by sludge application. About 82 to 92 per cent of adsorbed Cd was retained by cation exchange and complexing sites. Soils treated with sludge increased the amount of exchangeable Cd but reduced the amount of complexed Cd compared with the fertilized soil. Cadmium retention by cation exchange became more dominant as the amount of Cd in the soil was increased.     

ADSORPTION OF HERBICIDE-DERIVED p-CHLOROANILINE RESIDUES IN SOILS: A PREDICTIVE EQUATION

Relationships between the adsorption of p-chloroaniline and the original adsorbate concentration were investigated for five soils ranging in organic matter content from 1.7 to 8.1 per cent and in clay content from 0.5 to 21 per cent. Adsorption data were analyzed applying the linear form of the Freundlich equation. To evaluate the general relationship between adsorption of p-chloroaniline by soils and the solution concentration (C₀), values of partition coefficient (Kp), reflecting the magnitude of distribution of chemical at equilibrium between soil colloids and solution were calculated. The experiments showed that the regression parameters were significantly correlated with the soil organic matter content. A comparison of the experimental results obtained with other soils and the calculated values gave satisfactory agreement.     

土壤中活性镍变化的动力学及其应用

研究了镍在６种不同性质土壤中活性的动力学。结果表明,土壤活性镍随时间变化的规律可用双常数速率方程很好地加以描述。参数ｋ反映了变化过程的速率,即ｋ值愈大者,其变化的速率愈小。