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1.
壤和堆肥中四环素类抗生素的检测方法优化及其在土壤中的降解研究 总被引：2，自引：0，他引：2
在对土霉素（OTC）、四环素（TC）和金霉素（CTC）3 种四环素类抗生素的高效液相色谱（HPLC）检测分析方法以及在土壤和堆肥中的提取方法进行改进和优化的基础上,采用该方法进行了 3 种抗生素在土壤中的降解试验。结果表明,选用 Agilent Eclipse XDB-C8（4.6150 mm,5 m）色谱柱,以 0.01 mol/L草酸/乙腈/甲醇（79/10.5/10.5,v/v/v）为流动相,紫外检测波长 268 nm,流速 1.0 mL/min,进样量 5 L,采用外标法定量,可使 3 种四环素类抗生素在 20 min 内全部洗脱并达到基线分离; 在 0~10 mg/L 范围内,抗生素浓度与峰面积呈显著的线性关系,相关系数（r）均 0.999。土壤和堆肥样品中的 OTC、TC 和 CTC可用1 mol/L NaCl/0.5 mol/L 草酸/乙醇（25/25/50,v/v/v）混合溶液提取,其回收率在 76.0%~92.5% 之间。加入到土壤中的抗生素在 25℃下避光培养 49 d 后,在壤土和红土中的降解率分别是 67%~72% 和 36%~46%,对应的半衰期分别为 2630 d 和 4675 d,说明抗生素在壤土中比红土中容易降解。此外,3种抗生素在壤土中的半衰期没有显著性差异,而在红土中 CTC 和 TC 的降解速率显著高于 OTC。 相似文献
2.
哲里木盟盐渍土类型、利用现状及改良利用对策 总被引：7，自引：1，他引：7
本文阐述了内蒙古哲里木盟盐土、碱土、盐碱化土壤的分布与类型 ,在对目前改良利用现状加以分析的基础上 ,结合其所含盐分类型、含量等因素 ,提出了适宜哲里木盟农牧业生产实际的改良利用对策 ,展望了改良利用前景 相似文献
3.
Yu. N. Vodyanitskii 《Eurasian Soil Science》2012,45(3):321-328
In line with the present-day ecological and toxicological data obtained by Dutch ecologists, heavy metals/metalloids form
the following succession according to their hazard degree in soils: Se > Tl > Sb > Cd > V > Hg > Ni > Cu > Cr > As > Ba. This
sequence substantially differs from the succession of heavy elements presented in the general toxicological GOST (State Norms
and Standards) 17.4.1.02-8, which considers As, Cd, Hg, Se, Pb, and Zn to be strongly hazardous elements, whereas Co, Ni,
Mo, Sb, and Cr to be moderately hazardous. As compared to the general toxicological approach, the hazard of lead, zinc, and
cobalt is lower in soils, and that of vanadium, antimony, and barium is higher. The new sequence also differs from that of
the metal hazard in soils according to the Russian standard on the maximal permissible concentration of mobile metal forms
(MPCmob): Cu > Ni > Co > Cr > Zn. Neither an MPCmob nor an APCmob has been adopted for strongly hazardous thallium, selenium, and vanadium in Russia. The content of heavy metals in contaminated
soils is very unevenly studied: 11 of them, i.e., Cu, Zn, Pb, Ni, Cd, Cr, As, Mn, Co, Hg, and Se, are better known, while
the rest, much worse, although there are dangerous elements (Ba, V, Tl) among them. 相似文献
4.
P.J. Coughtrey 《Soil Use and Management》1988,4(3):84-90
Abstract. Mathematical models describing radionuclide transport in soil developed for radiological assessment have increased in complexity over the last decade. In particular fairly simple 'black box', equilibrium approaches have given way to more complex, time-dependent, process-orientated methods. The increase in complexity of these models has outstripped the available data to specify, test and validate them. Current issues in model development include those that are associated with times up to a million years. Further development requires new laboratory and field research to provide adequate data to justify the inclusion or omission of known soil processes. 相似文献
5.
M. A. Timofeev V. A. Terechova P. A. Kozhevin 《Moscow University Soil Science Bulletin》2010,65(4):179-182
The potential of biotesting to detect and analyze Cd pollution in soils was studied. This paper identifies a number of approaches,
such as PICT and discriminant analysis, which may open new perspectives for ecotoxicology. 相似文献
6.
Abstract. Guidelines are proposed to indicate the range of drainage problems encountered under Scottish conditions, along with some of the main factors to be considered for the treatment of these problems. The identified categories are briefly discussed, together with the potential application of the guidelines. 相似文献
7.
S. Baken M. A. Larsson J. P. Gustafsson F. Cubadda E. Smolders 《European Journal of Soil Science》2012,63(6):839-847
Total vanadium (V) concentrations in soils commonly range from 20 to 120 mg kg?1. Vanadium added directly to soils is more soluble than geogenic V and can be phytotoxic at doses within this range of background concentrations. However, it is unknown how slow sorption reactions change the fate and effect of added V in soils. This study addresses the changes in V solubility, toxicity and bioavailability in soils over time. Four soils were amended with pentavalent V in the form of a soluble vanadate salt, and extractable V concentrations were monitored over 100 days. The toxicity to barley and tomato plants was evaluated in freshly spiked soils and in the corresponding aged soils that were equilibrated for up to 330 days after spiking. The V concentrations in 0.01 m CaCl2 soil extracts decreased approximately two‐fold between 14 and 100 days after soil spiking, and the reaction kinetics were similar for all soils. The phytotoxicity of added V decreased on average two‐fold between freshly spiked and aged soils. The reduced toxicity was associated with a corresponding decrease in V concentrations in the isolated soil solutions and in the shoots. The V speciation in the soil solution of the aged soils was dominated by V(V); less than 8% was present as V(IV). Oxalate extractions suggest that the V(V) added to soils is predominantly sorbed onto poorly crystalline oxyhydroxides. It is concluded that the toxicity of V measured in freshly spiked soils may not be representative of soils subject to a long‐term V contamination in the field. 相似文献
8.
Introduction Recent investigations in soil science have shown that physical properties of paddy soils are of great importance to rice-production. There is extensive literature on the chemical property of paddy soils, but little information on the physical property of paddy soils, especially under waterlogged condition. For studying the physical property of flooded paddy soils, it is necessary to collect the soil cores under an undisturbed condition. 相似文献
9.
E. Lacarce C. Le Bas J.‐L. Cousin B. Pesty B. Toutain T. Houston Durrant L. Montanarella 《Soil Use and Management》2009,25(1):57-65
Growing environmental awareness and advances in modelling have generated interest in soil monitoring networks. Data management tools have to be developed in order to store data, check for errors and retrieve data for sharing and for analysis. As a result, we have designed a web application and a database for the Biosoil project that focuses on European forest soils. Integral to the system are authentication of users and access rights to the modules and data. It also logs all activities of each user. During data submission, the system automatically manages data transfer from the flat file (ASCII file) to the database after compliance checks. Then error tracking is followed by automated expert checks. These checks identify potential mistakes that can be corrected or commented on by data providers. The database is intended to cope with the challenges of transnational monitoring and integrates data quality assurance/quality control mechanisms. Benefits from the architecture of the database and from the services provided by the software may be generalized to all soil monitoring databases in order to improve data management and quality control. 相似文献
10.
阐述了污染土壤植物修复技术消除污染物的吸收、积累、降解、抑制和转化作用的关键机制 ,并指出该技术存在的问题、局限性及其应用植物修复技术应注重的关键环节。研究表明植物根际对石油烃降解及抑制是这些化合物的主要损失机制 ,而金属的植物修复技术主要基于植物的稳定和积累作用。 相似文献
11.
Even though conservation tillage may be ideal for the semi-arid tropics (SAT) in view of results from studies and tillage practices in the U.S.A. and Australia, studies conducted in semi-arid regions of Africa appear to support the use of conventional tillage systems. Some of the reasons for this apparent discrepancy are because of the physical properties of the soils in semi-arid Africa, particularly the Sahelian zones where the soils are sandy, have high bulk densities and therefore low total porosities and form crusts upon wetting and drying. Consequently, no-till or reduced tillage systems that do not have the soil surface covered by residue in irder to prevent formation of crust as a result of raindrop impact, tend to lose water through runoff in a region where water economy is essential. Also, because these soils have inherently high bulk densities, conventional tillage systems appear to be suitable since they increase the macropores, reduce both bulk density and strength and thus ensure prolific root distribution and the resultant exploration of water and nutrients at greater soil depths. Notwithstanding, it seems that since most of the SAT soils are structurally unstable, further conventional tillage even though it has ephemeral advantages, may in the long term be exacerbating the problems of structural instability and their deleterious effect on water and soil conservation and therefore on crop production. We suggest that at this stage soil tillage research in the semi-arid regions of Africa and Asia should re-examine some of the concepts of conservation tillage in relation to soil physical properties and processes in order to obtain a tillage system that ensures high crop yields without destruction of the soil resource. 相似文献
12.
The most reliable method for determining carbon in soils is the dry combustion method, the technique of which was established for the first time by JUSTUS von LIEBIG in 1831 and for nearly a century his combustion technique, essentially unmodified save for improvements in materials, constituted the standard method for determination of carbon and hydrogen. PREGL (1), in his publication on organic microanalyses in 1916, reported an excellent method in which a carbon determination could be carried out in an hour with a sample of only a few milligrams. After that, his method was improved in many respects by many investigators (2,3). Since these methods require, however, both complicated and expensive apparatus as well as trained personnel and are time-consuming, they are not considered to be suitable for practical use in soil research laboratories at all. 相似文献
13.
固体废弃物及土壤中磷的形态分析技术 总被引：2，自引：0，他引：2
畜禽粪便等固体废弃物及土壤中磷的形态分析对于管理固体废弃物、提高磷素利用率、减少磷素流失风险具有重要意义。自20世纪初以来,已提出多种固体废弃物及土壤中磷素形态分析的方法,包括化学分级、酶水解法、X射线衍射(XRD)、红外光谱(FT-IR)3、1P核磁共振(31P NMR)、X射线吸收近边结构(XANES)等。本文系统总结了一些固体废弃物及土壤中磷素形态分析的方法,比较了其特点,指出只靠单一的方法并不能很好地鉴定固体废弃物及土壤中磷素的形态,必须综合考虑运用多种方法,从而为磷素形态分析提供方法选择的依据,同时为进一步发展固体废弃物及土壤中磷素形态分析新技术奠定基础。 相似文献
14.
A procedure was developed on the basis of the experimental-theoretical equation for calculating the parameters of soil erosion resistance (the bottom eroding velocity of flow), the principles of the erosion resistance theory, the experimentally obtained relationships between the main erosion parameters of Tajikistan soils (the size of water-stable aggregates and their cohesion), and other properties (the initial water content, the lumpiness, the contents of physical clay and humus, the porosity ratio, and the lower plasticity limit). For practical purposes, a simpler procedure is recommended to evaluate and map the erosion resistance of irrigated lands in the areas of typical serozems and mountain cinnamonic soils of Tajikistan from minimum initial information (the texture, lumpiness, and density of the soils and the content of plant roots). 相似文献
15.
《Communications in Soil Science and Plant Analysis》2012,43(9):949-957
Abstract Methods of soil decomposition for determination of heavy metal total content were considered. Two saline soils (chloride and sulphate solonchak solonetz) and one rich in organic matter were uzed for investigation. It has been established that decomposition by using HF‐HCl with a preliminary ignition at 500°C is a very suitable method. The type of the studied soils and the results obtained allow for this method to be recommended for decomposition of various soils. On the basis of experiments with modelled soils it has been proved that possibilities for heavy metal losses on ignition are created when NaCl content and the percentage of weakly bound heavy metals (water‐soluble, exchangeable, etc.) are high. Under the conditions of the experiment (acid soils ‐ pH 4.3 and 5.0) losses of Zn and Pb but not of Cu have been incurred. Although these cases are not typical, this requires the applicability of the method for such particular occasions to be checked. 相似文献
16.
The degree of spatial variability in the distribution of particle-size fractions has been determined for agrogray soils of an experimental field of Bryansk Agricultural Academy. The degree of spatial variability is close to the analytical error; for comparing different plots, particle-size distribution analysis has to be performed in two-three replicates. If the particular sets of data (e.g., data sets on the content of clay in the upper and lower parts of the plow horizon) are used, the statistical probability of differences increases. Cluster analysis can be used for the initial grouping of particle-size distribution data. 相似文献
17.
酸性土壤水溶性氟浸提方法的研究 总被引：2，自引：0，他引：2
本文比较研究了振荡、超声、沸水浴和烘箱4种浸提酸性土壤水溶性氟的方法,然后采用离子色谱法对浸提液进行测定,并通过对测定数据进行统计与方差分析来确定最佳浸提方式。结果显示,水土比5:1,浸提时间20 min、温度60℃是振荡法与超声法浸提酸性土壤水溶性氟含量的最佳条件。在此条件下,振荡法与超声法浸提的土壤水溶性氟含量无显著差异,标准偏差均小于0.3%。超声法浸提的酸性土壤水溶性氟含量显著高于各自最佳处理条件下的沸水浴法与烘箱法浸提的水溶性氟含量。在离子色谱测定水溶性氟过程中,质量控制样品均在1倍标准偏差范围内。因此,采用离子色谱法测定超声法或振荡法浸提的酸性土壤水溶性氟是一种可行的、准确的试验方法,特别对于批量土壤样品的测定具有重要意义。 相似文献
18.
R. J. A. Jones R. Hiederer E. Rusco & L. Montanarella 《European Journal of Soil Science》2005,56(5):655-671
The estimation of soil carbon content is of pressing concern for soil protection and in mitigation strategies for global warming. This paper describes the methodology developed and the results obtained in a study aimed at estimating organic carbon contents (%) in topsoils across Europe. The information presented in map form provides policy-makers with estimates of current topsoil organic carbon contents for developing strategies for soil protection at regional level. Such baseline data are also of importance in global change modelling and may be used to estimate regional differences in soil organic carbon (SOC) stocks and projected changes therein, as required for example under the Kyoto Protocol to the United Nations Framework Convention on Climate Change, after having taken into account regional differences in bulk density. The study uses a novel approach combining a rule-based system with detailed thematic spatial data layers to arrive at a much-improved result over either method, using advanced methods for spatial data processing. The rule-based system is provided by the pedo-transfer rules, which were developed for use with the European Soil Database. The strong effects of vegetation and land use on SOC have been taken into account in the calculations, and the influence of temperature on organic carbon contents has been considered in the form of a heuristic function. Processing of all thematic data was performed on harmonized spatial data layers in raster format with a 1 km × 1 km grid spacing. This resolution is regarded as appropriate for planning effective soil protection measures at the European level. The approach is thought to be transferable to other regions of the world that are facing similar questions, provided adequate data are available for these regions. However, there will always be an element of uncertainty in estimating or determining the spatial distribution of organic carbon contents of soils. 相似文献
19.
During a short-term recent period (about 50 years), many floodplains of the Nonchernozemic zone were used as meadows, croplands for growing row crops, or they were abandoned. This was done to supply the populations of industrial cities with vegetables. In this case, the agrotechnical, ameliorative, and some other measures applied were often incompatible with the properties of the floodplain soils and caused their degradation. Among these measures was the elimination of grasses in the crop rotation, the monoculture of row crops, inadequate irrigation inducing systematic waterlogging, and the wide use of heavy agricultural machines. The consequences of using such technologies were investigated by the authors; on these soils, row crop were grown for 30 years and, for the next 20 years, the soils were left under fallow. Based on the data obtained, methods for the floodplain soils’ protection against degradation are proposed. 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(7-8):511-529
Abstract A bioassay procedure is described for diagnosing aluminium toxicity in soils using short term root growth in extracted soil solution. Soil solution is extracted from moist soil which has been incubated at “field capacity”; for 4 days. Soil solution extracted is divided into two portions, each of which is treated with CaCl2 and H3BO3 to ensure that neither Ca nor B is limiting root growth. One portion is adjusted to pH 5.5 (pH adjusted treatment) with saturated Ca(OH)2 solution. Aliquots (11 ml) of each portion are separately dispensed into each of five polypropylene tubes. Seedlings (in our experiment Glycine max cv. Forrest) of uniform root length are inserted into each tube (one per tube) and grown for 48 h. The increase in root length during the 48 h growth period (root elongation) in the unadjusted solutions is expressed as a percentage of that in the pH adjusted solutions to derive relative root elongation (RRE) ‐ an index of aluminium toxicity. For 24 acidic surface soils, RRE using this soil solution bioassay was linearly correlated (r2 = 0.96) with RRE obtained from a soil bioassay (with unamended, CaSO4 and CaCO3 treatments). The latter is commonly used to obtain an index of aluminium toxicity. The proposed procedure is less time consuming and tedious than the soil bioassay, and interpretation of the result is unambiguous. 相似文献