红壤坡地土壤侵蚀定位土芯Eu示踪方法研究

利用人工模拟降雨装置和径流小区观测法相结合,详细阐述了Eu定位土芯的布设、取样及分析方法。试验研究结果表明,Eu定位土芯中子活化分析技术可以准确地测定不同地形部位的土壤侵蚀量。坡面侵蚀泥沙的分布表现为沉积、侵蚀交错出现,呈现波形变动,符合多项式的变化,相关关系也较好。休闲裸坡地上,整个坡面大都表现出上坡的上中部为侵蚀运移,下坡为沉积。布样80d后,发现测定流失泥沙结果与模型拟合结果的相关关系较好,准确度也较高。因此建议一般应在Eu土芯布样3个月后取样为好。预测结果和实际情况也比较相近,最大误差为7.671t/hm2,取样误差为1mm。     

京北山区板栗林主要养分元素积累与分配的研究

对北京北部山区板栗林主要养分元素积累与分配的研究结果表明:22年生板栗林的生物量为38638kg/hm2,生物量在干、枝、叶、花、果、果苞及根中的分配比例为52.18∶21.82∶3.70∶2.26∶2.65∶2.07∶15.33。板栗林5种主要养分元素N、P、K、Ca和Mg的贮存量为315.38kg/hm2,不同器官中5种养分元素贮存量排序为干>枝>根>叶>花>果苞>果。土壤层中5种养分元素贮存总量为206427.59kg/hm2,有效养分元素贮存量为16188.29kg/hm2,板栗林5种养分元素贮存量占土壤层5种养分元素贮存总量的0.15%,占有效养分贮存量的1.95%。板栗林对N的富集能力最强,各元素的富集系数排序为N>P>K>Ca>Mg。板栗林生态系统每积累1t干物质需要5种养分元素总量7.17kg,其中对Ca元素的需求量最大,P的最小。     

不同种植年限土壤微量元素对山银花品质的影响

[目的]探索不同种植年限土壤微量元素对山银花品质的影响,筛选山银花高产优质的最佳种植年限范围。[方法]采用野外调查和室内分析结合的方法,研究贵州省绥阳县不同种植年限山银花土壤微量元素对山银花品质的影响。[结果]不同种植年限下土壤pH值为4.67~6.01,土壤微量元素平均含量为:Cu 17.17~37.50 mg/kg,Mo 1.52~2.24 mg/kg,Mn 444.6~544.26 mg/kg,Zn 102.06~114.39mg/kg;山银花花蕾微量元素平均含量为:Cu 6.91~14.52 mg/kg,Mo 0.16~0.24 mg/kg,Mn 30.06~79.36mg/kg,Zn 12.73~23.54mg/kg;不同种植年限山银花绿原酸含量为2.988%~7.840%。[结论]土壤中Zn,Cu含量随种植年限增加而递增,Mo,Mn含量总体呈下降趋势。11~15a的山银花绿原酸含量最高,植物生长状况良好,花蕾微量元素含量总体随年限增加而增加。微量元素Cu,Zn能促进山银花的生长和绿原酸的合成,Mn元素与山银花的茎粗和叶片生长有关。     

菊花叶的矿物元素及其饮料配方的研究

菊花叶是南京市民喜吃的一种野菜,更是宾馆酒楼的上档菜之一。在食品工业步入天然、高科技时代,它具有应用价值和良好前景。测定了菊花叶的9种矿物元素的含量,对菊花叶饮料的生产工艺和配方进行了研究。通过正交试验及方差分析,确定出该饮料的最佳组合方式为A₃E₁B₂C₂D₃,即澄清的菊花叶汁用量30%,柠檬酸钾0.2%,蔗糖4%,蜂蜜2.2%,柠檬酸0.4%,水为63.2%。通小试,还确定出产品最适稳定剂配方为0.12%CMC和0.03%海藻酸钠复合使用     

红原1#泥炭地泥炭性质的初步研究

红原县 1#泥炭地是四川省若尔盖高原泥炭区的优良泥炭矿区之一。对该矿主矿段泥炭的品质作了初步综合考察,测定了泥炭的组成和元素的含量,其质量优于若尔盖地区其他的泥炭矿,具有较高的开发价值。     

Effect of vermicompost on some morphological,physiological and biochemical traits of bean (Phaseolus vulgaris L.) under salinity stress

Vermicompost can play an effective role in plant growth and development and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances and plant growth regulators and also high levels of macro and micro nutrients. The aim of this study was to investigate the effects of vermicompost and salinity interactions on some morphological and physiological features and concentration of mineral elements of bean (Phaseolus vulgaris L. cv. Light Red Kidney) cultivar. A factorial experimental with five different volumetric ratios of vermicompost and sand, including to: 0:100; 10:90; 25:75; 50:50 and 75:25 and four levels of salinity [20, 40, 60 and 80 mmol l^?1 sodium chloride (NaCl)], and control was conducted base on Randomized Complete Block Design with three replications. Bean seeds were sowed in plastic pots, the seedlings being sampled 42 days old (flowering stage).The results showed that vermicompost had significant effect on all studied traits under stress and non-stress (p ≤ 0.05).In this experiment, the vermicompost significantly increased the photosynthetic rate and concentrations of potassium (K⁺) and calcium (Ca²)⁺in leaf and root tissues. In salinity levels of 20, 40 and 60 mmol l^?1NaCl, all subjected ratios of vermicompost and in 80 mmol l^?1NaCl the ratios of 10% and 75% vermicompost, significantly ameliorated negative effects of salinity. In both stress and non-stress conditions, using 10% volume of vermicompost is recommended to improve the growth of bean plants.     

Deposition gradients and foliar and soil leachate concentrations of air pollutants in Scots pine stands of S.-E. Finland and the Karelian Isthmus,N.-W. Russia

Bulk precipitation and throughfall analyses in 50–100-year-old Scots pine stands revealed decreasing sulphur, nitrogen, calcium and magnesium deposition gradients, which extend from the St. Petersburg-Leningrad region and N.-E. Estonia to S.-E. Finland. The Ca and Mg deposition alleviate the acidifying effect of sulphur and nitrogen. The Scots pine canopies acted as a sink for ammonium and nitrate, while the canopy interactions increased sulphur, calcium and magnesium content in throughfall. Foliar S, N and Ca concentrations correlated positively with the corresponding deposition loads. In contrast, low foliar magnesium concentrations were detected in the vicinity of St. Petersburg. The results indicate that the sulphur and calcium deposition may have increased soil leachate S and Ca concentrations in the most polluted Scots pine stands.     

Soil Extraction of Readily Soluble Heavy Metals and As with 1 M NH4NO3-Solution - Evaluation of DIN 19730 (6 pp)

Background, Aims and Scope   The German DIN 19730 (1997) describes a method for the extraction of readily available trace elements from soil by shaking the soil with 1 M NH4NO3-solution. Based on this method trigger and action values for the transfer of heavy metals and arsenic from soils to plants have been published in the German Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV 1999). The chemical mechanisms involved in this soil extraction procedure were evaluated in some detail to create requirements to improve environmental risk assessment for soil contaminations.Methods   The chemical mechanisms involved when soil is extracted with 1 M NH4NO3-solution were evaluated. This was followed by a laboratory experiment to quantify the formation of soluble metal ammine complexes during the extraction. Cd, Zn, Ni, Cu, Co and Hg were extracted from 16 soils by 1 M NH4NO3, 1 M KNO3 and water. pH was adjusted in 5 steps between 5.0 to 7.5. The potassium cation (K+) and the ammonium cation (NH4+) behave similarly when cations from soil surfaces are desorbed, because they have almost identical ion radii (e.g. 0.133 and 0.143 nm). K+ does not form ammine complexes with other ions, whereas, due to the increasing formation of NH3 from NH4 by dissociation with rising pH, metal ammine complex formation is an important process in soil extraction when using ammonium salt solutions. A difference in the extraction efficiency of 1 M NH4NO3- and 1 M KNO3-solution for a given soil can therefore be attributed to the formation of soluble metal ammine complexes. Conclusion   Our experiments resulted in considerably higher extraction rates of Cu, Cd and Hg by 1 M NH4NO3-solution as compared to 1 M KNO3-solution. This effect, caused by the formation of soluble metal ammine complexes, was only evident in soils with higher readily soluble heavy metal contents and a soil pH above 6 – 6.5 for Cu and 7 – 7.5 for Cd. Further chemical mechanisms involved when soils are extracted with 1 M NH4NO3 are a moderate decrease in pH and an increase in ionic strength. Most of the colloids and parts of soluble metal-organic complexes are precipitated due to the high ionic strength. High ionic strength also decreases the activity of metal-OH+ species and the electrostatic potential of the particle surfaces, which in turn, increases the desorption of heavy metal cations from negatively charged soil surfaces. In contrast, the adsorption of anions like arsenate is favoured by the decreasing electrostatic potential. The prediction of heavy metal uptake by plants from the results of the 1 M NH4NO3-solution extraction fits well for elements, which are mainly bound by low strength electrostatic forces to the soils. Such conditions are found in acidic soils for Cd and Tl, which have a low tendency for hydrolysis compared to other heavy metals. The correlation between 1 M NH4NO3 soil extraction and plant uptake is less significant for Ni and Zn. Only low positive correlation coefficients have been found for Pb, As, Hg and for the Cu-uptake by wheat. Imprecise prediction of plant uptake of heavy metals by the extraction with 1 M NH4NO3-solution is mainly caused by conditions leading to an overestimation of plant availability such as elements are strongly bound to soils, or low soluble trace element contents in soils. Neutral to alkaline soil pH can also lead to imprecise prediction due to increasing formation of soluble metal-organic (Cu, Pb, Hg) and metal ammine (Hg, Cu, Cd) complexes and less importantly due to the formation of colloids. Therefore, at low 1 M NH4NO3-extractable soil contents usually no high plant contents are to be expected. Recommendation and Outlook   Extraction of soil with 1 M NH4NO3-solution is a suitable method for the determination of readily soluble and plant available trace element contents. The chemical soil extraction process may cause misleading predictions of the transfer of trace elements to plants for some soil properties. This knowledge should be used to improve risk assessment of soil contaminations. It has to be considered, that the processes involved in plant uptake of trace elements are too complex to expect that just one soil extraction method can always guarantee a correct prognosis of toxicological significant element contents in plants. Soil analyses may be used for the preliminary examination of suspicious areas and the demarcation of contaminated areas. The results of soil analyses should be checked additionally by plant analyses especially under conditions with a high probability for misleading results by the 1 M NH4NO3-extraction. Alternatively, extraction with 1 M KNO3-solution can be performed to exclude the effect of metal ammine complex formation.     

沼气肥养分物质和重金属含量差异及安全农用分析

对山西省高平市不同沼气肥有机质、养分和重金属含量进行比较分析,结果表明:沼气肥的p H值均呈碱性。鸡粪沼液中有机质、全N、P、K含量均高于猪粪沼液,秸秆沼液中有机质和全K含量高于鸡粪和猪粪沼液。沼渣富含有机质,且秸秆沼渣有机质含量均高于猪粪沼渣。猪粪沼渣全N含量高于全P和全K,而秸秆沼渣全K含量高于全N和全P;两类沼渣中有效P含量占全P的比重最大。3种沼液的中、微量元素均以Cl含量最高,且超过农田灌溉水质标准(GB5084-2005);Ca和Mg含量次之,Cu含量最低。6个沼渣的中、微量元素均以Ca、Fe含量较高;3个猪粪沼渣均以Cl含量较少,而3个秸秆沼渣均以Mn、Cu含量较低。1号猪粪沼渣As含量超过有机肥料标准(NY525-2012)。由此可见,部分沼液和沼渣可能存在有害物质过高的问题,从而影响其农用的价值和效果,存在潜在的生态环境风险。同时,应加强相关标准的制定和完善,以确保沼气肥的安全、高效农业利用。     

Air oxidation of S(IV) in cloud-water samples

Aerobic oxidation of S(IV) was investigated in cloud-water samples collected at Great Dun Fell,U.K., as part of a wider project into cloud-water chemistry. The rate was found to be first-order in S(IV) concentration, and the reaction rate constant. k_S(IV), was found to vary from 10^–5 to 10^–3 s^–1. The rate constant was highly correlated with H⁺ concentration (pH 3.5 to 6.5) and Fe concentration (<0.02 to=">^–6 mol dm^–3). The aerobic oxidation of S(IV) does not contribute significantly to SO₂ oxidation in clouds at Great Dun Fell, however, the reaction may be of consequence in clouds and fogs at polluted or urban sites with elevated trace metal concentrations. Also, this reaction may be responsible for the oxidation of S(IV) in cloud-water samples during storage.