bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of selected cations and anions on pK‐0.5pCa values for a Mn oxide system
Authors: Wang F. L. , Yu T. R. , Huang P. M. 
Published: December 2011

AbstractWe studied the relative influences of Mn2+, Al3+ NO3− and SO42− on the K‐Ca relationship, as expressed by a pK‐0.5pCa value, in a Mn oxide suspension system using a double indicator electrode technique. With an increase in the quantity of solution Mn2+ and Al3+ in the system, Mn2+ ions showed a stronger effect than Al3+ on increasing pK‐0.5pCa values, though this was not the case when the amount of the cations added was low. The stronger effect of Mn2+ on the K‐Ca relationship was attributed to stronger specific adsorption of the Mn2+ ion on the Mn oxide as compared with Al3+. When K+ and Ca2+ were added after the addition of Mn2+ and Al3+, activities of K and Ca in equilibrium solution were higher than those when K+ and Ca2+ were added first, indicating that the exchange reaction of the cations on the Mn oxide was not fully reversible. Compared to NO3− added systems, the pK‐0.5pCa values for SO42− added systems were lower when the initial K/Ca molar ratios were 0.5 and 2. This effect of SO42− on the pK‐0.5pCa values was also related to the quantity of Ca ions in the system since no significant difference in pK‐0.5pCa values was observed between the SO42− and NO3− added systems when the K/Ca molar ratio was 8. The present results revealed that both cationic and anionic environments had a profound influence on the adsorption of K and Ca and, thus, the pK‐0.5pCa values in a Mn oxide system. The findings of this study help attain a better understanding of the chemistry of K in soils, particularly those with variable charge.
Maßstabsabhängige räumliche Variabilität mikrobieller Bodenkenngrößen in einem Buchenwald
Authors: Stork Rudolf , Dilly Oliver 
Published: December 2011

AbstractDie räumliche Variabilität des Gehaltes an mikrobieller Biomasse (Cmic), der mikrobiellen Respirationsrate (Basalatmung) und des metabolischen Quotienten (qCO2) wurde in sandigen Braunerden und Parabraunerden unter Buchenwald in Norddeutschland untersucht. Die höchste Variabilität der mikrobiellen Kenngrößen und damit der Abstand, ab dem die räumliche Unabhängigkeit der Proben gewährleistet war, wurde bei etwa 10 m erreicht und in Zusammenhang mit räumlicher Hierarchie diskutiert. Strukturelle Unterschiede zwischen dem Maßstab des 10 m‐ und des 50 m‐Rasters (Ah‐Horizont) wurden durch einen Bruch der Korrelationen von Cmic−Gehalt und der Gehalte an Corg, pflanzenverfügbarem Ca, Mg, K sowie Nt angezeigt. Hohe Cmic−Gehalte korrespondierten mit hohen Corg−Gehalten in unmittelbarer Stammnähe und in Ökotonbereichen wie Waldrändern und Lichtungen. Der qCO2 stieg nicht generell mit abnehmendem pH‐Wert. Hohe H+‐Konzentration und hoher Corg−Gehalt in der Streuauflage des Stammfußbereiches ließen sich mit verringerter mikrobieller Zersetzungsleistung erklären. Hohe Anteile an gegenüber niedrigen pH‐Werten toleranten Mikroorganismen, die leicht zersetzbares Substrat bevorzugen, scheinen im Stammfußbereich vorzuherrschen.
Intracellular and extracellular enzyme activity in soil with reference to elemental cycling
Authors: Duly Oliver , Nannipieri Paolo 
Published: December 2011

AbstractEnzyme activities play an important role for the transformation of elements and compounds in soil and, thus, were extensively analyzed for more than 4 decades. The activity of any enzyme in soil may not only be controlled by active organisms. Substantial parts of ‘extracellular’ enzymes may be stabilized by abiotic soil components maintaining their activity. Methods to discriminate the source of enzyme activity were summarized with emphasis on the approach plotting enzyme activity versus a feature integrating the microbial biomass after the addition of glucose and nitrate. Considering the quotient between enzyme activity and microbial biomass content, protease activity will be discussed with reference to nitrogen transformation in soils.
Abschätzung erhöhter Bodenbelastungen mit polychlorierten Dibenzo‐p‐dioxinen und Dibenzofuranen bei der bodenkundlichen Geländeaufnahme
Authors: Lenz Harald , Bächle Herbert , Schneider Jörg , Thater Michael , Stahr Karl 
Published: December 2011

AbstractUnsystematisch verteilte Bodenbelastungen mit polychlorierten Dibenzo‐p‐dioxinen und Dibenzofuranen (PCDD/PCDF) waren Anlaß für die Durchführung einer Stadtbodenkartierung in Rheinfelden (Baden). Diese teilweise sehr hohen Belastungen ließen sich nicht allein durch atmosphärischen Eintrag aus ansässigen Industriebetrieben erklären. Zur Ermittlung des Ausmaßes der Bodenbelastungen wurde als Methode die fallbezogene Stadtbodenkartierung gewählt.Der Stadtbodenkartierung lag nach Voruntersuchungen als Arbeitshypothese zugrunde, daß in Rheinfelden erhöhte PCDD/PCDF‐Bodenbelastungen an erkennbare Partikel gebunden im Boden vorliegen und deshalb durch eine bodenkundliche Geländeaufnahme erfaßbar sind.An etwa 3700 Bohrpunkten erfolgte eine Bodenansprache. Durch die flächendeckende, parzellenscharfe Kartierung konnten (hoch)bela‐stete von wenig bzw. unbelasteten Bereichen abgegrenzt werden. Es wurden etwa 720 Bodenproben entnommen und auf Schwermetalle untersucht. An 140 Proben wurden die PCDD/PCDF‐Gehalte bestimmt. Durch die Analytik wurde bestätigt, daß im speziellen Falle Rheinfeldens PCDD/PCDF‐Belastungen über 100 ng I‐TFQ/kg nahezu ausschließlich in den als stark anthropogen gestört eingestuften Böden zu finden waren, Diese Böden waren erkennbar mit solchen Beimengungen verunreinigt, die auf erhöhte PCDD/PCDF‐Gehalte hinweisen und durch die Geländeaufnahme erfaßbar sind.Eine eindeutige Beziehung zwischen angenommenen Leitparametern (Ba, Hg. Pb) und PCDD/PCDF konnte nicht nachgewiesen werden.Die Methode einer solchen bclastungsfallspezifisuh modifizierten Stadtbodenkartierung ist grundsätzlich für die Erkundung aller flä‐chenhaften Bodenbelastungen geeignet, die an feldbodenkundliche Merkmale gekoppelt sind. Sie kann im Einzelfall eine effiziente und kostensparende Erkundungsmethode darstellen.
Polychlorinated biphenyls (PCBs) in bulk soil and particle size separates of soils in a rural community
Authors: Wilcke Wolfgang , Zech Wolfgang 
Published: December 2011

AbstractIn a rural community (Stephanskirchen, Southern Germany) situated near a waste incineration plant six A horizons were sampled to determine 14 polychlorinated biphenyls (PCBs) in bulk soil and particle size separates (clay, silt, fine and coarse sand) and to test the suitability of alkaline saponification for PCB extraction. The PCB concentrations were higher in alkaline saponification extracts than in Soxhlet extracts. However, the extraction efficiency of up to fourfold chlorinated PCBs was lower and more than sevenfold chlorinated PCBs were destroyed. Nevertheless, alkaline saponification was suitable to determine the indicator congeners 28, 52, 101, 138, 152, and 180. The sum of the PCB concentrations ranged from 8.4 to 59.5 μg kg−1 which was as high as in soils of big cities. However, the concentrations did not reach the threshold value for agricultural purposes of 200 μg kg−1 as proposed in literature for the sum of the six indicator congeners. The hexachlorinated PCBs 138 and 153 were the most abundant (together > 50% in all samples) whereas PCB 1 could not be detected in any sample. On the average, PCB concentrations increased as particle size decreased. When normalized to Corg, however, the fine sand fraction had the highest PCB concentrations. A slight decrease of lower chlorinated PCBs as particle size decreased indicated an increasing state of degradation. The PCB compositions in the emissions of a comparable waste incineration plant (Bamberg, Bavaria) and in Stephanskirchen soils differed markedly. Therefore, we did not get any indications that waste incineration was a main source of PCBs in the examined soils. Instead, higher chlorinated technical PCB mixtures such as Clophen A 60 or Aroclor 1260 may be the most important sources.
Schwermetalle in Oberböden des Warthetals unter städtischem Einfluß
Authors: Lewandowski Piotr , Burghardt Wolfgang , Ilnicki Piotr 
Published: December 2011

AbstractIm städtischen Bereich der Stadt Poznan wurde die Schwermetallkontamination der Böden im Tal der Warthe untersucht. Aus fünf Talquerschnitten wurden 87 Proben der obersten Bodenschichten entnommen. Neben allgemeinen Bodenkennwerten wurden Gehalte an Arsen, Barium, Blei, Cadmium, Chrom, Eisen, Kupfer, Mangan, Phosphat und Zink bestimmt. Die Talböden weisen keine hohen Gehalte an Schwermetallen auf. Nur unterhalb von Abwassereinleitungen befinden sich erhöhte Gehalte an Blei und Cadmium. Eine starke Bodenkontamination wurde im Bereich der Altstadt gemessen. Dort wurden die höchsten Gehalte an Blei, Kupfer und Zink gefunden.Die Verteilung von Schwermetallen in Flußsedimenten weist darauf hin, daß als Ursache das Einbringen von Abwässern angesehen werden muß. Korrelationen zwischen den Elementgehalten und weiteren Bodenkennwerten (pH, Ton‐ und P‐Gehalt, C/N‐Verhältnis) werden vorgestellt.
Measuring interlayer potassium release rates from soil materials. I. Critical evaluation on the use of resin and other batch procedures for determining kinetic data
Authors: Springob Günther , Richter Jörg 
Published: December 2011

AbstractLaboratory procedures are evaluated for their principal suitability to derive unbiased kinetic data of interlayer K release (days to weeks, Luvisol ‘Ohlendorf’, loess, Ap horizon). The final intention is to relate K release rates to their main governing soil environmental variables rather than to conventional procedural standards. Of actual interest are technical aspects of quantifying the influence of solute K (CK), which is considered to be the most important among those variables. The relevant range is that of a few μM K, similar to the rhizosphere of plants where diffusion‐controlled, non‐destructive K release is thought to be of importance. Tested non‐resin batch techniques, e.g. the time dependent shift of K‐Ca exchange isotherms, are considered to be unsuitable because the derived release rates were markedly biased by shaking the suspensions. Generally, the batch technique just showed that additional proton induced release of nonexchangeable K (Knex) is negligible above pH 4. Ca‐resin procedures extracted considerable amounts of Knex but most of it had to be attributed to the addition of fresh (K‐free) exchange solution rather than to the presence of the resins. Further, an active regulation of CK in the intended range was only hardly possible via the resin/soil ratio but was inexact and only achieved with inacceptable effort. Further modifications, e.g. containing the resins in dialysis tubes, improved the technique but did not eliminate the main problems: Ca‐resin does not act as a real sink for K. H‐resins did act as a sink but, due to other constraints, are also rejected: CK is too low (< 1 μM, no effective regulation possible) and the pH of the suspension steadily declines (< 3 after one week). The one promising procedure among those tested was a continuous (non‐resin) percolation technique (> 900 h) which permitted a flexible regulation of CK by the percolation rate.
Geo‐ecological soil features and the vegetation pattern in an arid dune area in the Northern Negev, Israel
Authors: Beyer Lothar , Tielbörger Katja , Blume Hans‐P. , Pfisterer Ulrich , Pingpank Kristina , Podlech Dieter 
Published: December 2011

AbstractSoils are suggested to be an important factor influencing the vegetation pattern. In order to prove this hypothesis in an arid and sandy Negev ecosystem of longitudinal dunes and interdune corridors near Nizzana, Israel, the distribution of soil units and plant communities were compared on a very small‐distance level. The Nizzana site has a size of nearly 100 ha. 250 soil pits with 3–5 horizons were mapped and sampled within the soil geographical monitoring. Soil water capacity and cation exchange capacity were estimated from the field data. In addition 176 plots of 100 m2 were established around the soil pits with emphasis on plants, coveting the environmental gradient across the dune ridges. Plant mapping plots were arranged into groups with the same dominating perennial species and a key for the vegetation mapping was developed. In the investigated desert site topography, soil surface crust, soil texture and salt content partly can explain the distribution of plant communities. A soil classification proposal is based on these parameters and is a useful tool to indicate correlations between soil units and the vegetation pattern. Nevertheless, dependent on topography and surface and/or subsurface water flow as well as the occurrence of “fertile islands” the moisture and nutrient regimes influence the vegetation pattern with respect to plant growth to a greater extent than the soils themselves.
Dust characteristics and source‐sink relations in eastern West Africa (SW‐Niger and Benin) and South America (Argentinean Pampas)
Authors: Ramsperger Barbara , Herrmann Ludger , Stahr Karl 
Published: December 2011

AbstractIn order to quantify dust input and to describe its characteristics under different environmental conditions, and to get information on source‐sink relation, dust was collected monthly with bulk deposition samplers (open bucket type) in 2 and 4 m height over a 2—3 years period at different sites in West Africa (SW‐Niger and Benin) and in the semi‐arid Argentinean Pampas.Dust input, mineralogy (bulk and clay), chemical properties including total element content and particle‐size distribution showed a clear seasonal pattern in eastern West Africa. Far‐transported Saharan dust in the dry season could be distinguished from local material transported in the rainy season. In Argentina, high sand content of the samples pointed to an important participation of local components in the collected material. This was supported by higher contents of seaborne salts at the coastal sites, and the highest amounts of collected dust at the site of highest wind velocities. Due to the lack of seasonal differences in dust amount and its characteristics, and the aeolian genesis of the Pampas soils, a separation of local material and long‐range dust was not possible.
Reduction of herbicide contamination in flowing waters
Authors: Frede Hans‐Georg , Fischer Peter , Bach Martin 
Published: December 2011

AbstractA brief survey of potential pathways of herbicide transport in flowing waters is given. For a small watershed in Hesse (central Germany) during 4 spraying periods (spring and autumn 1995 and 1996) all point and non‐point sources were measured. It was proved that faulty spray practice occurred in 60% of 260 applications. However this source caused no evident herbicide contamination in running waters. More than 90% of the total herbicide load has been detected as point sources originating from the 40 farms connected to a sewage plant. Compared to these point sources, the pesticide pollution originating from runoff and subsurface drainage was not significant. An example is given describing how advisory measures in pesticide handling can reduce the loads by 80%.
New quality of assessment of microbial diversity in arable soils using molecular and biochemical methods
Authors: Schloter Michael , Zelles Laszlo , Hartmann Anton , Munch Jean Charles 
Published: December 2011

AbstractNew molecular and biomarker approaches allow now a better understanding of the microbial diversity in soils. Examples are presented to demonstrate the new performance of these approaches and the quality of results. Investigations of the diversity of a bacterial indicator genus as well as studies of the whole microbial community structure are presented. Genotypes of Ochrobactrum were isolated by immunotrapping and characterized by PCR — fingerprinting. On a fallow land no significant changes in the intragenus diversity of this indicator bacterium was observed over a period of one year. In contrast, crop rotation was accompanied by a shift in the dominant genotypes of Ochrobactrum, while the genetic potential was not affected.Phospholipid fatty acid (PLFA)‐pattern revealed significant shifts in the structure of the whole microbial community in a soil of a hop plantation as compared to a similar soil with crop rotation. The quantity of anaerobic bacteria, represented by the non‐ester linked fatty acids were lower in soil samples derived from crop rotation as compared to a former hop plantation soil, which was contaminated with copper. In contrast, the ester linked fatty acids which are present in a wide range of Gram‐negative and Gram‐positive bacteria, exhibited a reverse relation. Soil samples of the hop plantation contained low amounts of saturated ester linked fatty acids branching on the 10th C atom. This indicates that actinomycetes are present in relative small proportions in the hop plantation soil.
Nitrogen turnover in soil after application of animal manure and slurry as studied by the stable isotope 15N: A review
Authors: Dittert Klaus , Goerges Tjark , Sattelmacher Burkhard 
Published: December 2011

AbstractIn the last decades many aspects of nitrogen turnover have been studied by 15N methods. In this article contemporary 15N tracer as well as natural 15N abundance methods for the study of animal manure turnover are briefly reviewed. The nitrogen dynamics after application of farmyard manure and slurry are elucidated. Here, emphasis was put on results from 15N stable isotope work in the fields of nitrogen immobilization, nitrogenous trace gas emissions, turnover of organic nitrogen fractions, and finally plant uptake. Added nitrogen interactions, which must be considered when interpreting 15N studies, are discussed. Finally promising research fields for the use of stable isotopes are outlined.
Phosphorus availability, root exudates, and microbial activity in the rhizosphere
Authors: Schilling Günther , Gransee Andreas , Deuhel Annette , Ležoviž Grit , Ruppel Silke 
Published: December 2011

AbstractField and pot experiments showed that the P demand of wheat is highest in early stages of growth (up to 1.67 μg P per cm2 root surface and day). The needed orthophosphate ions H2PO4− and HPO42‐move from soil to the root by diffusion. This process is controlled by the concentration gradient of the diffusible phosphate and the effective diffusion coefficient according to Pick's first law. Root excretions (rhizodeposition) are able to affect both characteristics. The water soluble portion of rhizodeposition contains more than 50% of up to 8 different sugars, 10–40% carboxylic acids and 10–15 amino acids and amides. The composition varies in dependence on the age of the root parts and on nutrition (Zea mays L., Brassica napus L., Pisum sativum L.). Diffusion experiments using small soil blocks showed that 50–75% of the root exudates were decomposed by respiration within 3 days. The rest was largely chemically converted. Originally present sugars disappeared. Due to the biosynthesis of different organic acids from the individual sugars the mobilisation of Ca3(PO4)2 by Pantoea agglomerans increased when the sugar mixture was derived from the rhizodeposition of P deficient plants with more pentoses instead of glucose and fructose (mainly effect of anions). In the rhizosphere therefore a mixture of rhizodeposition and its conversion products exists which affects the binding of phosphorus in soil and the P transport to the root. This should be considered both for the development of new soil extractants and for modelling the P supply to plants.
The apoplast‐habitat of endophytic dinitrogen‐fixing bacteria and their significance for the nitrogen nutrition of nonleguminous plants
Authors: Hecht‐Buchholz Charlotte 
Published: December 2011

AbstractRecent attention has been drawn to plant‐growth‐promoting bacteria which colonize not only the rhizosphere and the surface of roots but also the interior of roots and shoots of higher plants. The bacteria are found in the apoplast i.e. intercellular spaces and xylem vessels. These so‐called endophytic bacteria are considered to be more effective in providing the host plant with nitrogen than associative rhizosphere bacteria on the root surface and appear to play an important role in biological nitrogen fixation (BNF) in nonleguminous plants. This is discussed in detail. Bacteria which have been found in the apoplast of nonleguminous plants include Azospirillum spp., Pantoea agglomerans, Acetobacter diazotrophicus, Herbaspirillum spp., Azoarcus spp. and Rhizobium spp. The significance of the apoplastic colonization of these bacteria for the nitrogen nutrition of tropical non‐legumes is discussed.
Potassium fertilization on sandy soils in relation to soil test, crop yield and K‐leaching
Authors: Wulff Frank , Schulz Volker , Jungk Albrecht , Claassen Norbert 
Published: December 2011

AbstractTo study the influence of potassium (K) fertilizer rate on soil test K values, crop yield, and K‐leaching in sandy soils, four long‐term fertilizer experiments (0–60–120–180 kg K ha−1 a−1) were initiated in 1988 in northern Germany on farmers fields. Clay content of the plow layer was about 4%, and organic matter between 2% and 5%. Plant available soil K was estimated with the double lactate (DL) method.Small grain cereals (rye and barley) did not respond to K fertilization in the 7‐year period even though the soil test value of the K‐0 plots decreased from ca. 90 to ca. 30 mg KDL kg−1 within 3 years. This value remained almost constant thereafter. Crop removal (including straw) of 75 kg K ha−1 a−1 was therefore apparently supplied from nonexchangeable K fractions. Compared to the optimum, no K application reduced the yield of potato by up to 21%, and that of white sugar yield up to 10%. Maximum potato yield was obtained by annually applying 60 kg K ha−1 which resulted in a test value of 60 mg KDL kg−1 soil. Maximum potato yield was also obtained at 40 mg KDL kg−1 soil, however, with a single application of 200 kg K ha−1. Similar results were obtained with sugar beet. This indicates that for maximum yield, even for K demanding crops, it is not necessary to maintain KDL values above 40 mg K kg−1 soil throughout the entire crop rotation.Soil test values increased roughly proportional to the K fertilizer level. About 120 kg fertilizer K ha−1 a−1, markedly more than crop K removal, was required to maintain the initial KDL of 90 mg kg−1. The K concentration of the soil solution in the top soil measured after harvest was increased exponentially by K fertilizer level and so was K leaching from the plow layer into the rooted subsoil. The leached quantity increased from 22 kg K ha−1 a−1 in the plot without K application to 42.79 and 133 kg Kha−1 a−1 in plots supplied with 60, 120 and 180 kg K ha−1 a−1 respectively. Soil test values around 100 mg KDL kg−1 on sandy soils, as often found in the plow layer of farmers fields, lead to K leaching below the root zone that may exceed the critical K concentration of 12 mg K T−1 for drinking water.
A modified procedure for staining arbuscular mycorrhizal fungi in roots
Authors: Vierheilig Horst , Piché Yves 
Published: December 2011

AbstractRoots were cleared by boiling in 10% KOH and rinsed several times with tap water. Thereafter roots were boiled in the staining solutions. The staining solutions consisted in different dyes (trypban blue (0.05%), anilin blue (0.05%) and acid fuchsin (0.01%)) which were dissolved in usual household vinegar (5% acetic acid). For best contrast, tryphan and anilin blue stained roots were destained with tap water, whereas acid fuchsin stained roots were destained with vinegar. All fungal structures were stained and clearly visible.