Precision of soil moisture measurements done with “Time Domain Reflectometry” and “Frequency Domain Probes” in heterogeneous forest soils Using “Time Domain Reflectometry” (TDR) and “Frequency Domain” (FD) technique soil moisture of a homogenized soil- substrate of silty loam was measured in the lab as well as soil moisture of the same silty loam and of two soils with coarser texture and more heterogeneous structure in situ. These measurements were compared with gravimetric soil moisture measurements done at the same measuring sites. Thus the measuring errors caused by soil heterogeneities should be assessed. The standard error of both, the TDR- and the FD- probes amounted to less than 1 Vol%, at the in situ measurements as well as in the homogenized substrate. In the homogenized substrate under relatively dry conditions soil moisture was overestimated to about 2 Vol% by both electronical methods, which is most likely the result of compactions in the contact zone between rods and the soil caused by the insertion of the rods. In the field both electronical methods, however, underestimated the soil moisture up to 14 Vol%. This applied especially to the surface of the mineral soil and under the influence of high stone contents. This deviation is interpreted as an effect of gaps along the rods, caused by the insertion. In loosely packed and stony upper soils we propose therefore to install the rods in homogenized autochtoneous soil material having settled to its natural bulk density instead of inserting them into the natural layered soil.
This study was designed to investigate the impact of three land-use practices in Thailand on soil organic matter (SOM) composition. The land uses were continuous farming (till), alley-cropping, and secondary forest. Samples, taken from the top 10 cm soil surface, were fractionated into clay- (< 2 mu m), silt- (2-20 mu m), and sand-sized particles (20-2000 mu m) prior to analyses of C, N, lignin-derived phenols and individual carbohydrates.As particle size increased, the C/N ratio and the concentration of liganin-derived phenols increased, whereas the degree of lignin oxidation as well as ratios of microbially derived hexoses to plant-derived penetoses decreased, Thus, the coarser the particle size, the less the SOM was altered by microbes. Seven years of alley-cropping increased SOM levels only little but considerably affected SOM composition by affecting the SOM of the sand fraction. The SOM concentration in the sand fraction increased in the order continuous farming < alley-cropping < secondary forest. In the same order, microbial alteration of lignin and carbohydrates of sand-sized SOM decreased. Both the different concentrations of SOM in the sand fractions as well as its different composition contributed, therefore, to different SOM among the sites. Increasing lignin-to-carbohydrate ratios for bulk soils and fractions in the order continuous farming < alley-cropping < secondary forest reflected such changes in SOM composition sensitively.
On a sandy tropical soil, organic materials (prunings of Leucaena leucocephala, Senna siamea and maize stover) with contrasting C/N ratio (13, 18 and 56, respectively) were applied at the rate of 15 t ha(-1)a(-1) in order to increase the amount of soil organic matter. Two light fractions (LF1 = LF > 2 mm and LF2 = 0.25 mm < LF < 2 mm) and the heavy fraction (HF) of the soil organic matter pool were determined by means of a combined density/particle size fractionation procedure and data obtained were related to soil nitrogen mineralization under controlled conditions and to nitrogen uptake by maize under field conditions. Under controlled conditions and when the LF1 fraction was excluded, nitrogen mineralization was found not to be correlated to total organic carbon content in the soil (R-2 = 0.02). The R-2-value of the linear regression increased considerably, when amount and C/N ratio of the LF2 fraction was taken into account in the regression analysis (R-2 = 0.88). Under field conditions, a multiple linear regression with amount and C/N ratio of HF, LF1 and LF2 better explained variation in crop nitrogen content and nitrogen uptake of maize (R-2 = 0.78 and 0.94) than a simple linear regression with total organic carbon (R-2 = 0.48 and 0.76). The results illustrate the importance of the two light and heavy organic matter fractions for estimating soil nitrogen mineralization. Determination of light and heavy soil organic matter fractions by density/particle size fractionation seems to be a promising tool to characterize functional pools of soil organic matter.
Using "Time Domain Reflectometry" (TDR) and "Frequency Domain" (FD) technique soil moisture of a homogenized soil-substrate of silty loam was measured in the lab as well as soil moisture of the same silty loam and of two soils with coarser texture and more heterogeneous structure in situ. These measurements were compared with gravimetric soil moisture measurements done at the same measuring sites. Thus the measuring errors caused by soil heterogeneities should be assessed. The standard error of both, the TDR- and the FD-probes amounted to less than 1 Vol%, at the in situ measurements as well as in the homogenized substrate. In the homogenized substrate under relatively dry conditions soil moisture was overestimated to about 2 Vol% by both electronical methods, which is most likely the result of compactions in the contact zone between rods and the soil caused by the insertion of the rods. In the field both electronical methods, however, underestimated the I;oil moisture up to 14 Vol%. This applied especially to the surface of the mineral soil and under the influence of high stone contents. This deviation is interpreted as an effect of gaps along the rods, caused by the insertion. In loosely packed and stony upper soils we propose therefore to install the rods in homogenized autochtoneous soil material having settled to its natural bulk density instead of inserting them into the natural layered soil.
On the ARINUS experimental sites in the Schwarzwald (SW Germany) since 1987 the mineral nutrition of Norway spruce was investigated using various experimental fertilizer treatments. The studies were focused on the nutrient Mg as acute Mg deficiency symptoms were observed at the beginning of the experiments. Treatments with ammonium sulfate, kieserite and dolomitic limestone were carried out to achieve an experimental modification of the Mg supply. In this paper, results on yellowing status, long-term foliar analysis, and data on the binding forms of Mg and Ca in the needles are presented. By; application of Mg containing fertilizers the Mg nutrition of the trees could be markedly improved. Thus, deficiency symptoms disappeared. Kieserite application resulted in the fastest response of foliar Mg concentrations; In contrast to Mg, Ca deficiency could not be observed. The results of the (NH4)(2)SO4 application show that high N input in ecosystems can amplify latent deficiency of mineral elements. Recently on many sites the risk of nutrient imbalances has developed as a consequence of improved N supply due to deposition. Thus, nutritional and site specific aspects should be payed more attention when liming and fertilization measures are planned. A higher percentage of deep rooting tree species as beech and fir could be useful for stabilizing mineral nutrition of forest canopies.
Three Lolium multiflorum inbred lines A, B and C and their hybrids (AB, AC, BC) were tested for their shoot dry matter (DM) production, P uptake (mg P pot(-1)), P utilization (mg DM . mg P-1) and P influx (P uptake rate per cm root length) by growing in plastic pots for a maximum period of 92 days at two P levels in a loess loam soil. The acid phosphatase activity of roots of inbreds A and C grown in nutrient solutions with 1, 10 and 100 mu mol P . L-1 was also determined using the hydrolysis of Nitrophenyl phosphate (NPP). Compared to the average of the inbreds DM production of the hybrids was 8% higher at high and 12% higher at low P level. With an increase of 14% and 25% DM respectively hybrid BC had the highest heterosis effect. The biomass production corresponded with the P uptake. Therefore, the P utilization efficiency of the hybrids was nearly the same as that of the inbreds. The increase in P uptake of the hybrids was related to the increase of root length. This means that the P uptake efficiency, i.e. the influx per unit of root remained unchanged between the inbreds and their hybrids. It can thus be concluded that the heterosis effect corresponds to an increase of P uptake caused by an increase of the size of the root system. The activity of the root phosphatases increased with declining P status of shoots and being absolutely higher in inbred A than C. Both inbreds responded within 3 days to a decreased P supply (from 100 to 1 mu mol P . L-1).
A procedure for quantifying minerals in particle size fractions of fine earth (<2 mm) is presented. Mineral fractions of the acid forest soils are characterised by various transition products. Transitional minerals between illite and vermiculite or smectite, polyhydroxy-Al polymers interlayered in smectite and vermiculite, as well as poorly crystalline compounds are present. Normative calculations with standard minerals, generally applied to rocks, cannot be used to quantify precisely minerals of these soil samples. Conventional qualitative and quantitative chemical analyses are therefore completed by microanalyses of well-identifiable minerals. The calculation procedure Is based mainly on a system of simultaneous linear equations. These are set up from the chemical contents of a particle size fraction on the one hand and from the corresponding clement contents of single minerals on the other hand. The contribution of single minerals to overall parameters can be calculated by programmed algorithms. The methodology was adjusted to different particle size fractions.
Nutrient ions entering the plant root from the soil solution, whether directly or through mycorrhizal fungi, first encounter the apoplast, a chemically complex compartment. The movement of ions in unmodified walls occurs in water-filled channels (diameter about 10 nm) and is influenced by electrical charges. Some positive charges occur in the wall, but the majority are negative. The permeability of the wall is variable, depending on its age and whether or not it has been further modified. Very young walls are less permeable than older walls, and the permeability of mature walls may be reduced by suberin and/or lignin deposits. It is not clear whether or not the other two main wall-modifying substances, mucilages and condensed tannins, also significantly reduce wall permeability. Casparian bands, which consist of suberin and lignin within radial and transverse walls, occur in the endodermis and exodermis. These layers form continuous cylinders within the root so that ion movement into the entire areas they surround is prevented. An important corollary is that Casparian bands dictate which cells are accessed by the soil solution and thus are in a position to absorb ions. It is postulated that a Casparian band-like modification also occurs in the walls of cork cells, based on observations of their impermeability to dyes. Suberin can occur in the form of lamellae which are deposited on all walls of endodermal, exodermal and cork cells. Unlike the Casparian bands, these lamellae limit movement between the apoplast and plasmalemma surface of the individual cells in which they occur. Condensed tannins, an addition to the walls of tree roots which results in them becoming brown, appear to function as antimicrobial agents rather than as permeability barriers. Further research is needed to investigate the structure of both unmodified and modified walls in a variety of species and under a variety of growing conditions.
In: pot experiments under field conditions the-PAM decrease in ten different soil samples from former industrial sites with:differing PAH. load were investigated over a period of:74 and 168 weeks,:15 but of 16. PAH according to OS EPA; (without acenaphthylene) were determined. Easily degradable organic matter, mineral fertilizers, synthetic surfactants and in some experiments also lime were added to the soil samples in varying amounts.Depending on the nature and quantity of the amendments,the biological activity and: (co-)metabolic decomposition of PAH by: soil. microorganisms could considerably be increased. In the different soil samples a decrease of the initial PAH contents between 12 and 90% was achieved within 74 weeks. Even from 74 up to 168 weeks for some soil samples a remarkable further decrease of the PAH contents could be observed.The decrease bf the extractable PAH with lime is mainly caused by microbial decomposition and formation of nonextractable residues. This behavior can befitted by two coupled exponential functions, one for an initial phase of rapid decomposition and the other for a:subsequent phase of slow decomposition Therefore two different processes (I, II) determine the decrease df PAH. In the first week of the experiment the decomposition rates for process:I amount-to 4,2-88,3 and for process II to 9,06-5,3 mg PAH . kg(-1) soil . week(-1); in the 168th week they are no longer determinable for process I and amount to 0,05-2,3 mg . kg(-1) . week(-1) for process II. Higher initial PAH contents often led to higher relative PAH decreases, but also to absolute higher contents of residues. The persistence of PAH is mainly determined by their bioavailability.PAH degradation is increased by the soil treatments. The addition of easily degradable organic matter (C/N ratio < 20).in a quantity of 30g . kg(-1) (w/w) combined with the addition of nitrate and-a;surfactant most effectively increased the degradation of PAH; Raising the pH of a very strongly acidic:soil Sample revealed a maximum PAH decomposition at a pH of 6.
The hydrocarbon load of contaminated soils is usually mainly adsorbed to the soil organic matter. The laboratory determination of; the sorption equilibration of volatiles suffers from severe-drawbacks due to volatilization losses of the analytes and low recoveries if liquid extraction methods are applied.The presented headspace technique for the determination of partition coefficients produces reliable results, also under adsorptive as I well as under desorptive conditions. It was shown that the volatiles tested are subject to rather severe ad-/desorption hysteresis which strengthens the necessity to determine the desorptive K-oc in contaminated sites. Additionally significant data were obtained that demonstrated a very strong effect of the organic matters quality on the partition ratios of volatiles.
The extent of nitrate leaching from urban soils in rural communities so far has hardly been studied. Therefore the nitrate leaching in the community of Schwaforden near Nienburg in Lower Saxony was estimated during one winter period. The small town of Schwaforden covers about 7.5% of the 950 ha large catchment area of a waterwork with serious nitrate problems. To estimate soil nitrate leaching, both soil use and degree of surface sealing in Schwaforden were determined and classified. In each class a number of representative sites were sampled seven times for mineral soil nitrogen in the course of one winter period. The leaching of soil nitrate for each site was estimated with the use of a mixing-cell solute transport model. Nitrogen mineralization as well as atmospheric nitrogen deposition were taken into consideration. It was found that home gardens, although covering only 3.5% of the total Schwaforden area, combined for 27% of the total amount of leached nitrate within the community. Heavy fertilization and large compost applications appear to be responsible for the high amounts of nitrate leached from such gardens. Hence, to protect groundwater against too much urban nitrate leaching, it may be necessary to evaluate the total home garden area in catchment areas of waterworks and eventually to restrict it.
Most of the nitrogen (N) in agricultural soils is organically bound, while the N uptake by plants and also the N losses from the soil-plant system into the environment are as inorganic N. The electro-ultrafiltration (EUF) method and the extraction by a CaCl2 solution extract an organic N fraction (Norg) that is thought to provide information about the amount of rapidly mineralizable N in soils. This paper aims to illustrate various aspects regarding the biological meaning of the Norg-fractions extracted by these two extraction methods and also the opportunities and limitations for predicting the mineralizable N based on an Norg analysis.From an evaluation of numerous data on EUF and CaCl2 extractable Norg fractions we concluded that these methods extract N compounds which can be used as indices for easily mineralizable soil N. However, both methods extract only some of the rapidly mineralizable N in soils, and some of the Norg ecxtracted appears to be from the more recalcitrant soil organic N. This was particularly true for the EUF-method. It may therefore be desirable to improve both the extractability and the selectivity of the extraction methods. This may be achieved by measuring extractable amino-N-compounds instead of the total extractable Norg.Evaluating the numerous field experiments done during the last decade shows that the calibration factors obtained for extractable Norg were not the same for different growing seasons, geographical regions and management practices. Theoretically, for each combination of these factors separate calibrations would be necessary. It is this inflexibility which appears to be the most serious drawback for the use of extractable Norg fractions in practice.A possible solution may be to combine the flexibility of a simulation model with additional information obtained by the analysis of extractable soil organic N. Further work in this direction may be desirable.
Environmental damages like forest decline in Northern Slovakia could be a result of long-distance transport of pollutants with the dominating north-west winds. On 10 sites, primarily in the northbound upper slopes of west-east oriented mountain ranges in Northern Slovakia, the extent of the heavy metal contamination in soils along a north-south transect was examined. Oi, Oe, Oa, A, and B horizons were sampled and the total concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined. The ranges of heavy metal concentrations in the forest floor were higher than reported for comparable samples from Bavarian soils except for Zn (Cd: 0.65–1.77; Cr: 12–40; Cu: 19–41; Ni: 8–24; Pb: 70–187; Zn: 31–92 mg kg−1), in the mineral soil the concentrations were lower. The depth distribution of the metal concentrations indicated a contamination with Cd, Cr, Cu, Ni, Pb, and Zn. The concentration differences between forest floor and mineral soil tended to be higher at the northern than at the southern sites for Cu, Ni, Pb, and Zn, indicating a long-distance transport from the north. Correlation and principal component analyses of the total metal concentrations revealed three groups: Cu, Pb, and Zn inputs mainly seemed to result from long-distance transport from the north, Cr and Ni inputs additionally from local sources. Cd probably had its origin mainly in local sources. This result was further confirmed by the grouping of the sites when clustered. Untersuchungen zur Schwermetallbelastung von Boden der Nordslowakei Umweltschaden in der Nordslowakei werden teilweise auf den Ferntransport von Schadstoffen mit den Nordwestwinden zuruckgefuhrt. Um diese Hypothese zu prufen, untersuchten wir auf 10 Standorten, uberwiegend in nordexponierten Oberhanglagen der west-ostlich verlaufenden Bergketten, das Ausmas der atmogenen Belastung mit Schwermetallen entlang eines Nord-Sud-Transektes. Dazu wurden die L-, Of-, Oh-, A- und B-Horizonte beprobt und die Gesamtgehalte von Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb und Zn bestimmt. Die Spannen der Schwermetallgehalte in den organischen Auflagen waren hoher als in vergleichbaren Proben aus Bayern, auser fur Zn (Cd: 0.65–1.77; Cr: 12–40; Cu: 19–41; Ni: 8–24; Pb: 70–187; Zn: 31–92 mg kg−1), im Mineralboden dagegen niedriger. Die Tiefenprofile der Metallgehalte wiesen auf Cd-, Cr-, Cu-, Ni-, Pb- und Zn-Eintrage hin. Die Differenz der Gehalte zwischen Auflage und Mineralboden war auf den nordlichen Standorten fur Cu, Ni, Pb und Zn hoher als auf den sudlichen, was auf einen Ferntransport aus Norden hinwies. Korrelations- und Hauptkomponentenanalysen der Schwermetallgehalte in den organischen Auflagen erlaubten die Unterscheidung von drei Gruppen: Die Cu-, Pb- und Zn-Belastung schienen hauptsachlich auf Ferntransport aus Norden zuruckzufuhren zu sein, die Cr- und Ni-Belastung zusatzlich auf lokale Quellen. Eingetragenes Cd stammte vermutlich aus lokalen Quellen. Dieses Ergebnis wurde durch die Gruppierung der Standorte mit einer Clusteranalyse bestatigt.
Zeitschrift für Pflanzenernährung und BodenkundeVolume 161, Issue 2 p. 186-186 Buchbesprechung Dunger, W. und H. J. Fiedler (Hrsg.) Methoden der Bodenbiologie. Gustav Fischer Verlag Jena, Villengang 2, 07745 Jena, 1997, 539 Seiten, Preis: DM 98-, ISBN 3-437-35050-1 W. V. Rheinbaben, Dresden-PillnitzSearch for more papers by this author W. V. Rheinbaben, Dresden-PillnitzSearch for more papers by this author First published: 14 December 2011 https://doi.org/10.1002/jpln.1998.3581610215AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume161, Issue2April 1998Pages 186-186 RelatedInformation
It was found that during a 4-day incubation of a Mollic Gleysol with 352 μl 1−1 methane in the headspace, the rate of methane consumption declined exponentially from an initial value of 9.13 μmol kg−1 hour−1 (about 5% of total CO2 evolved) according to first-order kinetics. The increase of dehydrogenase activity due to methane amendment did not exceed 15% of the control value and reached the maximum after two days of incubation. Methanoxidation und Dehydrogenaseaktivitat eines Mollic Gleysol Die Dehydrogenaseaktivitat eines Mollic Gleysols nach Methanzugabe (352 μl 1−1) wurde in einem 4 Tage dauernden Modellexperiment untersucht. Die Geschwindigkeit der CH4−Oxidation nahm exponentiell von 9.13 μMol CO2 kg−1 h−1 (ca. 5% des Gesamt-CO2−Effluxes des Bodens) gemas einer Reaktion 1. Ordnung ab. Die Zunahme der Dehydrogenaseaktivitat unter Einflus der CH4−Zugahe blieb unter 15% der Kontrolle und erreichte nach zwei Inkubationslagen ihr Maximum.
Ca deficiency disorders are common in micropropagated plantlets but little is known regarding the uptake of Ca in vitro. Ca uptake by in vitro-grown potato (Solanum tuberosum L. cvs. Bintje and Norland) plantlets was investigated when Ca levels were maintained but the total macroelement salts or just NH4, the major competing cation, were reduced in Murashige and Skoog (MS) medium. This increased the ratio of Ca:cations or Ca:NH4 as well as the osmotic potential of the medium. The increased Ca-cations improved Ca uptake of shoot tips, leaves, and stems while increased Ca:NH4 had no effect. MS medium macroelement dilution may improve Ca uptake by micropropagated plantlets and prevent Ca deficiency disorders.
Release rates of nonexchangeable K from Ap material of a Luvisol ('Eckerde' loess, 15% clay) are determined using a percolation procedure which avoids the common artifacts due to shaking or stirring soil;suspensions and thus provides less biased kinetic data. CaCl2 solution (10 mM(c), 20 degrees C, pH 5.8) is percolated through packages of soil aggregates (0.5-1 mm grain size, 0.5 g samples) with 0.02 to 25 ml h(-1) Solute K (C-K) was varied between <1 and > 10 mu M and is shown to have a dominant influence on the rates of interlayer K release. These increase exponentially below 3.5 CIM (no steady state but steady decrease of release rates in each sample). The difference between the related C-K between moderate and high release rates is as small as 1 mu M K. The average rates of a 10-day-interval, starting after 1.3 times the exchangeable K had been removed, are 40 mu mol K kg(-1) soil d(-1) at 4 mu M C-K and 240 mu mol kg(-1) d(-1) at 3 mu M C-K,C- respectively It is concluded that larger quantities of interlayer K become plant available in the studied soil if the C-K Of soil solutions gets below 3.5 mu M (for 10 mM, Ca, 20 degrees C, pH 5.8), probably because the dominant dioctahedral illites start to join the release process below this critical limit. The higher K concentration range was accounted for by K-Ca exchange isotherms which, by alteration of shape, indicate that K-nex release becomes measurable below 10 to 20 mu M K.It is further argued that existing diffusion or reaction kinetics approaches towards K release are incomplete because the influence of solute K is not considered.
Zeitschrift für Pflanzenernährung und BodenkundeVolume 161, Issue 6 p. 700-700 Buchbesprechungen Varma, A. (Ed.): Mycorrhiza manual. Springer-Verlag, Berlin, Heidelberg, New York, London, Paris, Tokyo, Hongkong. 1998, Abb. 33, Tab. 12, 542 Seiten. DM 148,-; ± 57.00; $ 99.95. ISDN 3–540-62437-6 G. Trolldenier, G. Trolldenier HannoverSearch for more papers by this author G. Trolldenier, G. Trolldenier HannoverSearch for more papers by this author First published: 14 December 2011 https://doi.org/10.1002/jpln.1998.3581610617AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume161, Issue6December 1998Pages 700-700 RelatedInformation
Within comparative studies on solute movement in tile drained agricultural fields in Schleswig-Holstein a bromide field test was conducted at two field sites. The soil of site 'Bokhorst' shows both spatial and profile heterogeneity with significant clay and silt contents (loam) whereas site 'Hohn' had a homogeneous particle size distribution within the profile with sand being the dominating particle fraction (sand) but with neglible spatial variability. Rainfall amount, drain dis charge and bromide concentrations in drain outflow were monitored over a 6 months period. A rapid response of drain discharge on rain events was observed for the loamy site but not for the sand. The simple water balance yielded +8.7 mm of drain discharge for site Bokhorst (loam) and -43 mm for the sandy site Hohn (sand).Largest bromide concentrations were detected shortly after chemical application at the loamy site. The bromide loss curve was characterized by simultaneous in- and decrease of flow rate and bromide concentrations. This solute behaviour was named 'event-dependent'. Bromide occurred in drain outflow at the sandy site not before 30 mm discharge and maximum concentrations were observed at the end of the monitoring period, Mass balance calculations revealed that 70.5% (loam) and 33% (sand) of the applied solute mass were transported from the fields via the tile drains. A two dimensional, advection dispersion equation based simulation model was applied to predict solute behaviour at site Bokhorst. Computed bromide concentrations were not in line with the observed preferential breakthrough curve. Consequences of preferential transport conditions in tile-drained field soils on surface water quality are briefly discussed, especially concerning the displacement of plantprotective agents and methodical difficulties.
The evidence of irregular occurring soil contamination with: poly- chlorinated dibenzo-p-dioxines and dibenzofuranes (PCDD / PCDF) have led to the pilot project 'Mapping of urban soils at Rheinfelden (Baden)'. The contaminations have been partly very high and could not be explained by atmospheric deposition. The mapping of urban sails at Rheinfelden was based on the hypothesis,:that,elevated :concentrations of PCDD/PCDF:are bound to visible particles in the soil and therefore should-be found:by soil mapping in the field. About 3700 soil cores including soil description have been:registered:By high resolution: mapping of the whole area based on sampling of each - even the smallest -property it: was possible to 'distinguish between highly contaminated and not or:only low contaminated areas. 140 Samples have been analysed for PCDD/PCDF content while 720 soil samples have been: taken in: order:ld:analyse heavy-metal content,:Out results showed that PCDD/PCDF:contaminations above 100 ng I-TEQ/kg (toxicity equivalents) were only found in soils with strong anthropogenic influence. These soils have been contaminated with visible admixtures leading to elevated PCDD/PCDF concentration. There:mas-no strong correlation between the key parameters (Ba, Hg, Pb) and the PCDD/PCDF contents.: Generally contaminations with areal relevance could be detected. by the:used modified mapping of urban soil.In this case::this method was an efficient and cost-reducing tool of detection.
