湖北省黄棕壤若干微量元素环境地球化学特征

在湖北省黄棕壤上采集32个土样，研究了微量元素B、Mn、Fe、Cu、Zn和Mo的总含量、有效态含量、它们在土壤剖面中的迁移分布等环境地球化学特征及其影响因素。所得结果如下：（1）湖北黄棕壤B、Mn、Fe、Cu的总含量较丰富，Zn的总含量中等，Mo的总含量缺乏；B、Cu、Zn、Mo的有效态含量较缺乏；（2）各微量元素总含量在黄棕壤剖面中的分布均以心土层中最高，而有效态含量均以表土层中最高；（3） Zn、Mo的有效态含量与总含量呈显著或极显著正相关；B、Mo的有效态含量与黄棕壤pH值呈极显著正相关，Fe、Zn有效态含量则与pH值呈显著负相关；除Fe外其他微量元素的有效态含量均与土壤有机质含量呈显著或极显著正相关。     

黑土农业区常量和微量元素环境地球化学特征

黑土常量元素组成表明黑土化学组成比较均匀,但Fe、Al在剖面中发生分异,有风化脱Si作用,黑土亚类间地球化学组成特征的差异与其分布区地势不同有关。对黑土中微量元素B、Cu、Fe、Mn、Mo和Zn的全量、有效态含量、它们在土壤剖面中的迁移分布等环境地球化学特征及其影响因素进行了研究,指出需要施用微量元素肥料,增加黑土中微量元素的含量,以促进该地区农业的可持续发展。     

浙江省土壤微量元素的构造地球化学特征

前人从气候、地形、生物等外力因素的影响入手,对土壤中微量元素的分布、迁移及其转化的地球化学规律进行了大量有益的工作。但是,对于地质构造体与土壤中微量元素分布的关系,构造运动对土壤中微量元素迁移及富集的影响,即内力作用方面,几乎完全缺乏研究。     

土垫旱耕人为土地球化学特征

研究了汾渭盆地的土壤旱耕人为土地球化学状态与有关影响因素。１．土垫旱耕人为土受施土粪堆垫作用改变了成土方向与过程，也改变了土壤地球化学特征。２．土垫旱耕人为土在成土过程受淋溶淀积、生物迁移富集，蒸发等作用，但被Ｃａ＾＋＋、Ｍｇ＾＋＋等离子饱和，使土壤呈偏碱性。３．土垫旱耕人为土不同亚类在成土过程中因生态环境的差异，其土壤地球化学特征稍有差异。     

吉林省黑土某些微量元素环境地球化学特征

根据吉林省第二次土壤普查资料 ,对黑土中微量元素B、Cu、Fe、Mn、Mo和Zn的全量、有效态含量、它们在土壤剖面中的迁移分布等环境地球化学特征及其影响因素进行了研究 ,得出如下结论 :①吉林省黑土B、Mn、Mo、Zn的全量缺乏 ,Cu、Fe的全量略低 ;②黑土B、Cu、Zn的有效态含量缺乏 ,其中Zn严重缺乏 ;③黑土剖面中 ,B、Cu、Fe、Mn、Mo、Zn等微量元素全量与有效态含量分布相似 ,均以淋溶层最低 ,表层和淀积层较高 (Mo的全量除外 )。微量元素有效态含量剖面分布中淀积层层次较深 ,表层富集程度稍强 ;④黑土中B、Fe、Mn、Mo、Zn的有效态含量与土壤有机质含量呈显著的正相关 ;B、Mo的有效态含量与 pH值呈显著正相关 ,而Cu、Fe、Mn、Zn的有效态含量则与pH值呈负相关 ;黑土B、Cu、Fe、Mn、Mo、Zn有效态含量与其全量均达到显著相关水平。根据吉林省黑土中微量元素全量和有效态含量分布的特点 ,需施用微量元素肥料 ,增加黑土中微量元素的含量 ,促进该地区农业的可持续发展     

黑土农业区常量和微量元素环境地球化学特征环境整治

黑土常量元素组成表明黑土化学组成比较均匀,但Fe、Al在剖面中发生分异,有风化脱Si作用,黑土亚类间地球化学组成特征的差异与其分布区地势不同有关.对黑土中微量元素B、Cu、Fe、Mn、Mo和Zn的全量、有效态含量、它们在土壤剖面中的迁移分布等环境地球化学特征及其影响因素进行了研究,指出需要施用微量元素肥料,增加黑土中微量元素的含量,以促进该地区农业的可持续发展.     

外源有机磷在黄棕壤中的淋溶和转化特征

采用Bowman和Cole提出的有机磷分级体系,分3个灌水量对外源活性有机磷β-甘油磷酸钠在黄棕壤中的淋溶和转化特征进行了研究。结果表明,大于50mm的灌水量可以使β-甘油磷酸钠发生淋溶。施入黄棕壤中的β-甘油磷酸钠在24h内可以转化为速效磷和中活性有机磷,灌水量愈大,速效磷和中活性有机磷积累的土层也愈深。中稳性有机磷和高稳性有机磷含量没有明显变化。     

贵州开阳地区新元古代灯影组白云岩风化成土剖面微量元素地球化学特征

硒是人体必需的微量元素,土壤中的硒含量受基岩的控制,研究土壤中硒的分布情况,对合理开发利用土地资源具有重要意义。通过对开阳地区红粘土剖面的结构、颜色、微量元素、稀土元素分布特征研究,提出红粘土层可划分为两层:底部为暗紫褐色粘土,含有很高的Se元素及其它微量元素和稀土元素;顶部为紫红色粘土-灰黄色粘土,Se元素以及其它微量元素、稀土元素含量较低。基岩是红粘土剖面中硒元素的物质来源,其是土壤中硒含量的主要控制因素,另外,Fe含量、pH值、有机质也是微量元素包括硒元素、稀土元素富集的重要的控制因素,硒元素在铁质层和红粘土底部超常富集,这两层中硒含量分别是中国土壤硒平均含量的14.35倍和34.78倍。     

Rare earth elements and other trace elements in wastewater treatment sludges

In order to evaluate the possibility of contamination of soil with trace elements by the application of sludges to soil, the contents of rare earth elements (REEs; La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and other trace elements (Be, As, Ag, Cd, Sb, Cs, Bi, and U) in wastewater treatment sludges were determined. In sludges of night soil treatment plants (night soil sludges) and sludges of wastewater treatment plants in the food industry (food industry sludges), the distribution patterns of REEs normalized versus average REEs in the continental crust were almost flat. It was considered that the REE patterns of uncontaminated sludges reflected the pattern of the continental crust. The crust-normalized REE patterns of sludges of wastewater treatment plants in the chemical industry (chemical industry sludges) and municipal sewage sludges did not always show flat plots. The sludges that did not show a flat REE pattern were considered to be contaminated with some of the REEs.

The coefficient of variation of each element determined among the 10 samples of night soil sludges and the 14 samples of sewage sludges ranged from 34 to 77% and from 26 to 84%, respectively. Among the 10 samples of food industry sludges and the 10 samples of chemical industry sludges, the coefficient ranged from 60 to 143% and from 67 to 172%, respectively. The variations of the content of each element among the food industry sludges or the chemical industry sludges were larger than those among the night soil sludges or the sewage sludges.

The contents of Be, As, Cs, REEs, and U in all the sludges were lower than or the same as those in a field soil. Some of the food and chemical industry sludges contained larger amounts of Ag, Cd, and Sb than the soil. All the night soil sludges and sewage sludges contained much larger amounts of Ag and Bi than the soil.     

Crop contamination by selected trace elements

Goal and Background  The regulatory limit for the allowable concentration of heavy metals (HM) in agricultural soils should be based both on HM status and on soil parameters that influence HM mobility. In this paper, a soil categorization scheme is proposed which is based on the main factors that influence HM mobility in soils. The scheme also makes use of the existing regulatory limits for total concentrations of trace elements in Slovak soils but additionally takes into account the potential ability of the soils to mobilize trace elements. A map of the Slovak Republic showing the soil categorization using this scheme is presented. Methods  Besides total soil content of Cd, Pb, Cr, Hg, As, Cu, Zn, Ni, soil parameters with dominant influence on HM mobility are included in the scheme pH, organic matter content, quality of humus represented by spectral parameter Q⁴ ₆ and content of fraction f < 0.01 mm. Point rating approach was used for categorization. Database of localized soil data from 3556 locations was used for creation of map in GIS environment. Results  Based on the point scoring method described herein, soils are ranked from a (the least risk of crop contamination) to d (medium risk). Categories e and f are reserved for soils where the risk exceeds the allowable regulatory limits. For each of the six categories, the most suitable usage of agricultural land is recommended. The Slovak map presented shows that the main factor that affect the spatial distribution of each soil category is soil parent material which governs the existing total HM content and the predisposition for certain soil types to have high HM mobility. Agricultural usage of land in Slovakia is in most cases limited by exceedences of Cr and Ni, originating from widespread flysch rock parent material. Conclusions  Application to regional geochemical data shows that, for more than half of Slovak agricultural land, risk of crop contamination is low. For the rest of the area, planting should consider sensitivity of crops to HM uptake. Recommendation and Outlook  Evaluation of suitable agricultural usage based on HM contamination risk, should include not only the total HM content but also the potential for HM mobility, which can increase the risk of plant contamination. Where HM mobility data are not available, soil parameter data that influence HM mobility can be used to predict the potential HM soil contamination hazard.     

Dissolved organic matter sorption by mineral constituents of subsoil clay fractions

The retention of dissolved organic matter in soils is mainly attributed to interactions with the clay fraction. Yet, it is unclear to which extent certain clay‐sized soil constituents contribute to the sorption of dissolved organic matter. In order to identify the mineral constituents controlling the sorption of dissolved organic matter, we carried out experiments on bulk samples and differently pretreated clay‐size separates (untreated, organic matter oxidation with H₂O₂, and organic matter oxidation with H₂O₂ + extraction of Al and Fe oxides) from subsoil horizons of four Inceptisols and one Alfisol. The untreated clay separates of the subsoils sorbed 85 to 95% of the dissolved organic matter the whole soil sorbed. The sorption of the clay fraction increased when indigenous organic matter was oxidized by H₂O₂. Subsequent extraction of Al and Fe oxides/hydroxides caused a sharp decrease of the sorption of dissolved organic matter. This indicated that these oxides/hydroxides in the clay fraction were the main sorbents of dissolved organic matter of the investigated soils. Moreover, the coverage of these sorbents with organic matter reduced the amount of binding sites available for further sorption. The non‐expandable layer silicates, which dominated the investigated clay fractions, exhibited a weak sorption of dissolved organic matter. Whole soils and untreated clay fractions favored the sorption of ”︁hydrophobic” dissolved organic matter. The removal of oxides/hydroxides reduced the sorption of the lignin‐derived ”︁hydrophobic” dissolved organic matter onto the remaining layer silicates stronger than that of ”︁hydrophilic” dissolved organic matter.     

北京市平谷区农用地土壤有机质空间变异特征

采用传统统计、地统计及地理信息系统(GIS)相结合的方法,初步研究了北京市平谷区农田土壤有机质(SOM)含量的空间分布规律及其影响因素.传统统计分析结果表明,研究区土壤样本呈对数正态分布,平均值为15.36 g·kg-1,变异系数为0.32,属中等变异程度.方差分析表明,高程和土地利用类型均对研究区SOM含量的分布有显著影响.地统计分析表明,研究区SOM含量空间变异具有一阶趋势和各向异性特征;由空间自相关部分和随机部分引起的空间变异性程度大体相当,具有中等的空间相关性.结合普通Kriging插值方法,获得了研究区SOM含量的空间分布图,比较分析表明研究区农用地SOM含量的空间分布是自然和人为利用因素共同作用的结果.     

Distribution of exogenous phytase activity in soil solid–liquid phases and their effect on soil organic P hydrolysis

The bioavailability and stability of organic phosphorus (P) in the soil may be affected by exogenous phytase (EPase) activity and distribution, but remain poorly understood. The distribution of EPase activity and hydrolysis ability of EPase on organic P in soil solid‐liquid phases was investigated. The EPase addition to soil suspension (1:20, w/v) from three soil types (red soil, brown soil, and cinnamon soil) under three treatments (untreated soil, removing clay from soil, and removing organic matter from soil) with different characters in the solution and solid phases was assayed. The results showed that the disappearance pattern of EPase activity from solution was similar for all soils, whereas the enzyme activity on the solid phase was dependent on soil types and treatments with the greatest in red soil and untreated soil. When EPase was added to soils, the adsorption ratio of organic matter and clay was 10 to 25% and 3 to 7%, respectively, with sorption capacity of organic matter being significantly (p < 0.05) stronger than that of clay. Additionally, soil dehydrogenase activity, which is the indicator of overall soil microbial activities, increased after EPase addition and the two enzymes showed significant negative relation in the soil suspension and solution. At the same time, the organic P decreased significantly (p < 0.05) after the addition of EPase in the soil solid, which had a varied rate under –40% after incubating 192 h, whereas organic P in the solution phase increased significantly (p < 0.05). This study demonstrated that organic matter had a strong protective and adsorptive effect on EPase effectiveness and microbes mightbe directly affect EPase longevity and decay. This finding suggests that EPase activity in the solid phase played a more important role in organic P hydrolysis.     

江西鄱阳湖平原区农田土壤微量元素空间分异特征及其影响因素

【目的】开展土壤微量元素空间分异及其影响因素的分析,能更客观地阐明土壤微量元素变化的内在机理,对田间土壤肥力的有效管控和保障人类健康、保护土壤生态环境具有重要意义。【方法】在江西省丰城市鄱阳湖平原农田区,采用网格布点法布设283个采样点,每个采样点取0-20 cm表层土壤,对样点数据用三倍标准差法剔除异常值20个,实际利用样点数为263个,分析了土壤样品pH、质地、氮、磷、钾和硼(B)、锰(Mn)、钼(Mo)、硒(Se)、碘(I)、氟(F) 6种微量元素的含量。采用地统计学理论、方差分析、相关分析以及回归分析方法,对鄱阳湖平原区农田土壤6种微量元素的含量、空间分布特征及其影响因素进行分析。【结果】B、Mo含量均值处于丰富与上限值之间;Mn含量均值为330.24 mg/kg,处于缺乏水平;Se、I含量均值处于适量水平;F含量均值为474.59 mg/kg,处于边缘水平;6种微量元素含量均为中等程度变异,但各元素含量变异程度有所差异。B、Mn、Mo元素的最优插值模型为指数模型,Se、I、F均为球状模型。I元素的块金效应<25%,其他5种微量元素处于27.09%~41.77%。6种微量元素含量的空间分布格局差异较为明显,除Se元素不缺乏外,其余5种微量元素均处在缺乏水平。B、Mn、F含量均受到土壤类型、耕层质地的显著影响,Mn、Mo含量与坡度、pH间均达到极显著相关水平,Mn、Se、I含量与全磷含量显著相关,坡向与到河流的距离与6种微量元素含量未达到显著相关关系,其他影响因素仅对某些种元素表现出显著或极显著相关关系。在B、I含量的主要影响因素中,以耕层质地的影响最大;在Mn、Mo元素含量的主要影响因素中,以pH的贡献率最高;Se元素含量与土壤类型、全磷、坡度、高程之间达到显著或极显著相关水平,以全磷的影响程度最高;F元素含量与土壤类型、耕层质地、全氮含量相关显著,且全氮为主要影响因素。【结论】1)研究区域土壤B、Mo的含量总体较高,I、Se含量适量偏上,Mn总体上较为缺乏,F处于边缘水平;6种元素含量均为中等程度变异。2)土壤微量元素B、Mn、Mo的最优插值模型为指数模型,Se、I、F则为球状模型;除I具有强烈的空间自相关外,其余5种元素表现为中等程度的空间自相关。3)微量元素含量影响因素中,坡向、到河流的距离与各元素含量间未达到显著相关关系;B、I含量均受耕层质地的影响最大,Mn、Mo含量主要受pH的影响,Se含量主要受全磷的影响,F元素含量则主要受全氮的影响。     

Humus balancing in Central Europe—concepts,state of the art,and further challenges

Humus‐balancing methods are simple tools for the assessment of interactions between agricultural land use and soil organic matter (SOM). Aside from this commonality, approaches for humus balancing differ considerably with regard to their specific aim, scope, and methodical approach. The term “humus balance” covers both simple models to quantify SOM change in arable soils, or soil organic C (SOC) change in particular, and models that refer to the optimization of soil productivity in arable soils by calculating organic‐fertilizer demand, without quantifying SOM or SOC change. This situation naturally has caused much discussion and misunderstandings. Against this background, the aim of this review is to systematically explore the different methodical approaches to humus balancing in order to contribute to a more sophisticated discussion of this model family, its opportunities, and limitations. As humus balancing has long history as well as special actual relevance in Germany, and, lately Switzerland, we focus on these countries and discuss the different approaches that are presently available and applied there. We argue that humus balances can be roughly categorized into “ecological” and “agronomical” approaches based on their specific concepts and methodology. Ecological humus balances comprise a strong link to quantitative SOM change, while humus balances of the agronomical family refer to the maintenance of soil productivity without a quantitative link to SOM change. Lately, some models have been presented that link the two concepts. However, we identify that humus‐balancing methods often are insufficiently validated, partly because the validation of agronomical humus balances is not easily possible without a very comprehensive field‐experimental basis. Further, the comparability of different approaches even within the two concept families is low at present, indicating the need for a comparative model evaluation for a proper assessment of the methods.     

Erodibility in relation to water‐dispersible clay for some soils of eastern Nigeria

Water dispersible clay (WDC) can influence soil erosion by water. Therefore, in highly erodible soils such as the ones in eastern Nigeria, there is a need to monitor the clay dispersion characteristics to direct and modify soil conservation strategies. Twenty‐five soil samples (0–20 cm in depth) varying in texture, chemical properties and mineralogy were collected from various locations in central eastern Nigeria. The objective was to determine the WDC of the soils and relate this to selected soil physical and chemical attributes. The soils were analysed for their total clay (TC), water‐dispersible clay (WDC), clay dispersion ratio (CDR), dispersion ratio (DR), dithionite extractable iron (Fed), soil organic matter (SOM), exchangeable cations, exhangeable sodium percentage (ESP) and sodium adsorption ratio (SAR). Total clay contents of the soil varied from 80–560 g kg⁻¹. The USLE erodibility K ranges from 0·02 to 0·1 Mg h MJ⁻¹ mm and WEPP K fall between 1·2 × 10⁻⁶–1·7 × 10⁻⁶ kg s m⁻⁴. The RUSLE erodibility K correlated significantly with CDR and DR (r = 0·44; 0·39). Also, a positive significant correlation (r = 0·71) existed between WEPP K and RUSLE K. Soils with high clay dispersion ratio (CDR) are highly erodibile and positively correlates (p < 0·51) with Fed, CEC and SOM. Also, DR positively correlates with Mg²⁺ and SOM and negatively correlate with ESP and SAR. Principal component analysis showed that SAR, Na⁺ and percent base saturation play significant role in the clay dispersion of these soils. The implication of this result is that these elements may pose potential problem to these soils if not properly managed. Copyright © 2005 John Wiley & Sons, Ltd.     

基于小白菜Cd吸收推算土壤Cd安全阈值

Cadmium(Cd), a common toxic heavy metal in soil, has relatively high bioavailability, which seriously threatens agricultural products. In this study, 8 different soils with contrasting soil properties were collected from different regions in China to investigate the Cd transfer coefficient from soil to Chinese cabbage(Brassica chinensis L.) and the threshold levels of Cd in soils for production of Chinese cabbage according to the food safety standard for Cd. Exogenous Cd(0–4 mg kg~(-1)) was added to the soils and equilibrated for 2 weeks before Chinese cabbage was grown under greenhouse conditions. The influence of soil properties on the relationship between soil and cabbage Cd concentrations was investigated. The results showed that Cd concentration in the edible part of Chinese cabbage increased linearly with soil Cd concentration in 5 soils, but showed a curvilinear pattern with a plateau at the highest dose of exogenous Cd in the other 3 soils. The Cd transfer coefficient from soil to plant varied significantly among the different soils and decreased with increasing soil p H from 4.7 to 7.5. However, further increase in soil pH to 8.0 resulted in a significant decrease in the Cd transfer coefficient. According to the measured Cd transfer coefficient and by reference to the National Food Safety Standards of China, the safety threshold of Cd concentration in soil was predicted to be between 0.12 and 1.7 mg kg~(-1) for the tested soils. The predicted threshold values were higher than the current soil quality standard for Cd in 5 soils, but lower than the standard in the other 3 soils. Regression analysis showed a significant positive relationship between the predicted soil Cd safety threshold value and soil p H in combination with soil organic matter or clay content.