bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualisation of oxidizing power of rice roots and of possible participation of bacteria in iron deposition
Authors: Trolldenier Günter 
Published: February 2007

AbstractThe oxidizing power of rice roots was observed in narrow transparent root boxes containing different media. Plants precultivated in nutrient solution were embedded in semisolid agar medium to observe oxidation of ferrous iron cations and leuco methylene blue as well as solubilization of ferrous sulfide. In the presence of ferrous sulfate reddish brown coloration due to formation of ferric oxide/hydroxide was observed around the roots and on the root surface during one day of incubation. When agar medium blackened by ferrous sulfide was used, the root zone became transparent. Within a few hours leuco methylene blue was oxidized to methylene blue on and near the roots. Furthermore, seedlings were grown in agar medium containing ferrous sulfide inoculated with soil filtrate. Besides diffuse ferric iron precipitation, iron was also deposited on spherically shaped structures in the rhizosphere and near the agar surface as well as in slimy layers appearing on the root surface. The spherical structures and slimy layers were obviously bacterial colonies extending with time. As the roots grew old, parts of them turned black. In the rhizosphere, black spots occurred resembling colonies of sulfate‐reducing bacteria. Rice was also grown in sand supplemented with nutrients and iron sulfide. While root growth was straight in agar, it was twisted in the sand medium. Again, heavy ferric iron deposition occurred on the root surface. On older root parts the lateral roots became blackish. The results suggest participation of bacteria in ferric iron deposition in the rhizosphere of rice.
Soils of the Manas River Area in Northern Xinjiang, Peoples Republic of China
Authors: Guoying Yuan , Lichtenfeld Adolfo , Stahr Karl 
Published: February 2007

AbstractThe Manas River Valley is situated in the centre of the continental landmass of Asia. The natural conditions in this region on the northern slope of the Tian Shan Mountains are characterized by an arid climate in an temperate geographical position (N 43°–46°, E 85°–87°), with extreme cold winters and high temperatures in summertime. The rivers, which are fed by glaciers, were formerly bordered by gallery forests (Tugais) along their main parts. There occurs an altitudinal sequence of soils but also a high variability within the same altitude due to changes of rocktype, relief, landuse and age of land surface. All the northern mountain slopes are mainly covered by loess deposits. The former forest‐steppe Kastanozems and semidesert Xerosols are affected by severe erosion, which destroyed the former zonality there.In the transition zone to the desert, a quick change in the inclination, in the parent material (from loessial deposits to fine‐textured alluvial quarternary deposits) and in the water supply (the groundwater rises up to the soil surface) take place. For this reason the Xerosol‐Yermosol soil landscapes include soils like Gleysols, Solonchaks, Solonetz, Fluvisols and also Regosols. The great contrasts between winter and summer temperatures, the occurence of high temperatures when water supply is good and fine textured soils with high evaporation lead to the development of very fertile sites. They have a humusrich good structured topsoil, a favourable root penetrability and a high water capacity. On the other hand these soils are under natural and cultivated conditions affected by serious salinization in some parts of the area.
Metallspeziierung in Bodenlösungen mittels Dialysen‐ und Ionenaustauscherverfahren
Authors: Dietze G. , König Nils 
Published: February 2007

AbstractMit Hilfe eines abgestuften Trennverfahrens wurden die Bindungsformen der Hauptgruppen‐ und Übergangs‐Metallkationen zweier Bodenlösungen in Gegenwart organischer Inhaltsstoffe ermittelt. Durch einfache Dialysenmethode mit H2O‐Vorlage sind besonders schwach ausgeprägte Assoziationsgleichgewichte festzustellen. Durch variierte Zusätze von Fremdelektrolyten und eines Kationenaustauscherharzes werden salzartige Elementspezies von stabil organisch komplexierten Metallionen unterschieden. Experimente mit einem Kationenaustauscherharz im Direktkontakt mit der Bodenlösung werden gegenübergestellt.Den Ergebnissen zufolge kann nach drei typischen Metallbindungsformen differenziert werden, solche, deren Bindungscharakter salzartig anorganisch ist (K, Na), solche, die die negative Überschußladung der organischen Makroanionen ausgleichen (Ca, Mg, Mn, Zn, Cd), und solche, die mit den organischen Anionen stabile Komplexverbindungen eingehen (Cu, Cr, Pb, Fe, Al).
Determination of phytotoxic soil aluminium by electroultrafiltration
Authors: Mühling Karl‐Hermann , Steffens Diedrich , Mengel Konrad 
Published: February 2007

AbstractThe experiments address the questions of whether phytotoxic Al can be determined by electroultrafiltration (EUF). Spring barley (Hordeum vulgare) was grown in pot experiments on 28 soils differing widely in their characteristics. Al toxicity was measured in terms of root parameters and top growth. On soils rich in EUF extractable Al typical Al toxicity symptoms were found in roots and tops. EUF extractable Al obtained at the cathode (EUF‐Al, cathode) was correlated with root fresh weight (R2 = 0.554), root length (R2 = 0.653), root diameter (R2 = 0.729) and fresh weight of tops (R2 = 0.681). The Al obtained at the anode was not correlated with any of these plant parameters. It is supposed that this anionic Al consists of non toxic organic Al complexes. Correlations between plant parameters and KCl‐exchangeable Al were less close than those for EUF‐Al (cathode). Correlations between soil pH and plant parameters were in between the correlations for exchangeable Al and EUF‐Al (cathode).
Die Abschätzung von Nitratausträgen aus landwirtschaftlichen Nutzflächen mit Hilfe von Nmin‐Daten
Authors: Simon Wolfgang , Huwe Bernd , van der Ploeg Rienk R. 
Published: February 2007

AbstractAn zwei Stellen im Oberrheingraben in Baden‐Württemberg wurden Untersuchungen zur Nitratauswaschung von vorwiegend landwirtschaftlich genutzten Flächen durchgeführt. Im Rahmen der Untersuchungen wurde ein Verfahren entwickelt, mit welchem die Sickermengen und die Nitratausträge geschätzt werden können. Das Verfahren benutzt Nmin‐Werte, welche mindestens viermal pro Jahr vorliegen sollten. Das neuentwickelte Verfahren wird erläutert und Ergebnisse aus den Untersuchungen werden dargestellt.
The Separation of Low Molecular Weight Humic Acid Fractions and their Characterisation by HR‐C‐13‐NMR in Solution
Authors: Fründ R. , Lüdemann H.‐D. , Zech Wolfgang 
Published: February 2007

AbstractHumic materials from the O‐horizon of a Ferric Podzol and from the H‐horizon of a Sapric Histosol were fractionated by dialysis into a low and a high molecular weight fraction. Each fraction was characterized by quantitative solution C‐13‐NMR. The low molecular weight fractions showed remarkably well resolved C‐13 spectra, due to carbohydrates and their decomposition products.
On the Lipidic Fraction of some Typical Mediterranean Soils from Micaschists
Authors: Solinas V. , Melis P. , Premoli A. , Gessa C. 
Published: February 2007

AbstractThe lipidic fraction extracted from Rankers and Cambisols developed under the same pedoclimatic conditions was studied using chemical and physical methods. Their amounts extracted from different horizons varied from 0.10 to 0.66 g/100 g soil or from 2.7 to 33.3 g/100 g soil organic matter. UV‐visible, NMR and IR analyses indicate a rather homogeneous constitution of the lipidic fraction of the examined soils, characterized by a prevalence of long aliphatic saturated chains and only traces of aromatic compounds. X‐ray diffractometry gives evidence of the presence in all horizons of ozocerite, a crystalline mineral wax which can be considered an accumulation metabolic product.The characteristics of the lipids of these soils, shown by the acid number and by the E2/E3 ratio, can be used as an index of their bioactivity.
Effect of Irrigation Water Quality on Release/Precipitation of Ions in a Vertic Ustochrept
Authors: Dubey D. D. , Gupta Ram K. , Tiwari S. C. , Sharma O. P. 
Published: February 2007

AbstractA laboratory study was conducted on a smectitic clay soil (Vertic Ustochrept) to assess the release/precipitation of ions from cation balance as a result of irrigation with chloride, chloride‐bicarbonate and chloride‐sulphate water each containing 50 meq/l t.e.c.The study shows that irrigation waters having electrolyte concentration of 50 meq/l or more containing either chloride or chloride and bicarbonate ions should not be used for irrigating these soils irrespective of their SAR because they create sodicity. The waters containing both chloride and sulphate ions result in calcium precipitate buildup in soil. Although indiscriminate use of such waters may lead to concurrent buildup of salinity in the absence of adequate leaching.
Quantity and intensity relationships in predicting P availability of soils in Sri Lanka
Authors: Kumaragamage Darshani , Keerthisinghe Gamini 
Published: February 2007

AbstractIn a greenhouse experiment, P uptake by rye grass (Lolium multiflorium L.), from four representative soils of Sri Lanka were found to be signifikantly correlated with P intensity (r = 0.65**) and quantity (r = 0.68**) measurements. The incorporation of maximum buffer capacity (MBC) values in multiple regression improved the relationship of P uptake with P quantity but not with P intensity. Multiple regression equation indicated that at equal quantity levels, increasing buffer capacity tends to increase P uptake, indicating that the quantity parameter was buffered by MBC.A seedling experiment of 14 days duration using mustard (Brassica juncea L.) seedlings illustrated that P intensity had a more pronounced effect on P uptake (r = 0.80***) than P quantity (r = 0.43*). The incorporation of MBC values improved the relationship between P quantity and P uptake, but unlike the previous experiment the multiple regression equation indicated a negative relationship between MBC and P uptake at equal quantity levels confirming the importance of P intensity when P uptake is considered for a shot period.
Kurzzeittests zur Abschätzung langfristiger Wirkungen potentieller anorganischer Schadstoffe auf die mikrobielle Aktivität von Böden
Authors: Wilke Berndt‐Michael , Keuffel Anne B. 
Published: February 2007

AbstractEs wurde versucht, mit Perfusions‐ und Kleinlysimeteranlagen langfristige Effekte von Cadmium, Blei und Fluor auf die mikrobielle Aktivität einer sandigen Braunerde im Kurzzeittest zu simulieren. Als Vergleichsobjekt diente der Schadstoffdüngungsversuch B 4 der Biologischen Bundesanstalt in Berlin. Mit der Perfusionstechnik war es möglich, Langzeit‐wirkungen von Blei‐ und Cadmiumbelastungen auf die Dehydrogenase‐aktivität des Versuchsbodens nachzuvollziehen. Nur extrem hohe Zusätze von 200 mg Cd/kg und 4000 mg Pb/kg Boden wirkten stärker hemmend als im Langzeitversuch. Durch Freisetzung von OH‐Ionen und organischer Substanz wurden negative Effekte der Fluorgaben im Perfusionsversuch teilweise kompensiert.Die Kleinlysimetertechnik war weniger geeignet, Langzeitwirkungen der Schadstoffe im Kurzzeitexperiment zu erfassen, da hier störende Begleitionen und nicht sorbierte Schadstoffe nur sehr langsam ausgewaschen werden. Dehydrogenaseaktivitätmessungen zeigten im Vergleich zu ATP‐Gehalten und Nitrifikation die langfristige Hemmung der mikrobiellen Aktivität am besten an.
Entwicklung eines Computerverfahrens zur Berechnung der hydraulischen Leitfähigkeit von wassergesättigten Böden mit der Bohrlochmethode
Authors: Kretzschmar Ruben , Huwe Bernd , Van Ploeg Rienk R. Der 
Published: February 2007

AbstractEin iteratives Verfahren wurde entwickelt für die Berechnung der Wasserleitfähigkeit mit der Bohrlochmethode. Ergebnisse wurden verglichen mit Daten von Ernst (1950) und von Boast und Kirkham (1971). Die erzielten Ergebnisse waren denen von Boast und Kirkham sehr ähnlich, aber unterschieden sich vielfach erheblich von denen von Ernst. Das DIN‐Verfahren (DIN‐Norm 19682) ist damit in Frage gestellt.Im Vergleich zu dem Verfahren von Boast und Kirkham bietet das iterative Verfahren einen wesentlich Vorteil. Es ist einfach und ermöglicht die Berechnung von c‐Werten, welche bei Boast und Kirkham (1971) nicht tabelliert sind. Allerdings ist das Verfahren mit einigen Rechenaufwand verbunden. Die notwendigen Berechnungen lassen sich jedoch auf einem Personal Computer (PC) durchführen und erlauben eine beliege Genauigkeit. Ein Computerprogramm (in Quick‐BASIC) wird Interessenten auf Wunsch zugeschickt.
Estimation of phosphorus uptake capacity by different zones of the primary root of soil‐grown maize (Zea mays L.)
Authors: Ernst Manfred , Römheld Volker , Marschner Horst 
Published: February 2007

AbstractA method is described which allows determination of the nutrient uptake capacity by different zones of individual roots of soil‐grown plants. Examples are given for phosphorus uptake by different zones of the primary root of maize. Agar strips with labelled phosphorus (32P) are placed on the soil‐root interface of root zones of different age. After 24 h autoradiographs are made of the soil‐root interface and phosphorus uptake rates determined by plant analysis.Along the primary root the relative phosphorus uptake capacity declines per unit root length from 100% in 1 day old root zones to about 25–30% in 26 day old root zones. The change in the extension of the phosphorus (32P) depletion zone along the root axis indicates that the uptake capacity for phosphorus of root hairs was maximal upto 4 days and declined thereafter. The decline in capacity for phosphorus uptake from apical to basal root zones probably reflects the decline in root hair viability. The relative high uptake capacity in basal root zones is therefore at least partially due to the uptake capacity of the cortical cells.
Characterization of the soil aeration status by plant and soil analyses
Authors: Glinski J. , Schlichting E. , Stepniewska Z. 
Published: February 2007

AbstractIn differently aerated sites of two catenae under forest (Luvisols) and meadow (Gleysols) in Poland it was investigated if aeration in the period 1980–1983 could be characterized by the indicator I0 = N (in plants : soils): Mn (in plants : soils). In the Luvisol catena I0 was significantly correlated with ODR and in the Gleysol catena with ODR and Eh, but in neither of them with air volume. In both catenae “active” and “total” manganese fractions were a suitable basis for I0 calculation. In the Gleysol catena the investigation of top‐ (0–20) and subsoil (20–50 cm) appeared to be necessary when only the “active” Mn is considered.
Distribution and Concentration of Pb and Cd in Two Adjacent Luvisols under Grassland and Forest in Denmark
Authors: Jensen Niels Philip , Svensmark Bo 
Published: February 2007

AbstractThe effect of land use (forest and grassland) on the deposition and mobility of Pb and Cd has been studied by extraction with 1M HCl, 1M NH4Ac/HAc and 1M NH4Ac. The soils were described pedologically and the main physical and chemical parameters were determined. The Pb concentration in the A horizon is higher in the profile under forest than in the profile under grassland. We assign this difference to the filter action of the forest. The Cd concentration is highest in the grassland profile because the forest soil is more degraded and Cd is leached to a higher degree in this soil. Both metals are more mobile (easier to extract) in the forest because the forest soil is most acidic, and because a greater part is bound to organic compounds (humic and fulvic acids) which are more abundant in the forest than in the grassland. The concentrations of Pb and Cd in the A horizons are 26 ppm and 0.1 ppm under the forest and 9 ppm and 0.2 ppm under grassland, respectively.
Zum jahreszeitlichen Nitratgehalt und zur Nitratauswaschung von landwirtschaftlich genutzten Böden in Baden‐Württemberg
Authors: Gölz‐Huwe Hildegard , Simon Wolfgang , Huwe Bernd , van Der Ploeg Rienk R. 
Published: February 2007

AbstractAn fünf Stellen in Baden‐Württemberg wurden zwischen 1984 und 1987 umfassende Untersuchungen zum Stickstoffhaushalt von Böden landwirtschaftlicher Nutzflächen durchgeführt. Dabei wurde auch die Nitratdynamik im durchwurzelten Bodenbereich erfaßt und eine Vielzahl von Nmin‐Proben gezogen.Es zeigte sich, daß der Nmin‐Vorrat im Boden (bzw. der Nitrat‐Vorrat) jahreszeitlich keine Konstante ist, sondern daß charakteristische Jahresgänge auftreten, mit Maxima im Frühling und im Herbst. Das Maximum im Herbst unterliegt einer potentiellen Auswaschungsgefährdung. Es wurde weiter festgestellt, daß die Nitratauswaschung über Winter mit dem Nmin‐Wert (bzw. mit dem Nitratwert) im Herbst korreliert, aber nicht mit ihm identisch ist. Außerdem ergab sich, daß die Verlagerung von Nitrat über Winter in leichten Böden vorwiegend als Mischungsvorgang betrachtet werden kann, aber in schweren Böden eher als kombinierter Mischungs‐ und Verdrängungsprozeß gesehen werden muß.
Bacterial composition and N2‐fixation of some Egyptian soils cultivated with wheat (Triticum aestivum L.)
Authors: Fayez M. 
Published: February 2007

AbstractThe composition of the microflora, N2‐fixing bacteria particularly, in different soils cultivated with wheat in Egypt was investigated in some samples collected from the fields after applying the agricultural practices recommended for wheat cultivation and just before sowing. The influence of carbon sources, mineral nitrogen and water regimes on potential dinitrogen fixation (acetylene reduction assay) in soils was investigated. The bacterial population densities including‐N2‐fixing organisms were related to a number of environmental factors such as organic matter content. Among diazotrophs, Azotobacter spp. and Azospirillum spp. were encountered in higher densities in comparison with clostridia. Unamended soils showed a lower acetylene‐reducing activity (0.5–61.5 nmoles C2H4 g−1 h−1). Addition of glucose (1% w/w) greatly enhanced such activity being the highest (86.9–2846.5 nmoles C2H4 g−1 h−1) in the clay soil with the highest organic carbon content (1.42%). Glucose amendment had no significant influence on acetylene reduction in the saline soil. N2‐fixation in barley straw‐amended (1%) soils was not much higher than in unamended soils. Concentrations of up to 70 ppm ammonium‐nitrogen depressed N2‐fixation in soils that received barley straw. Acetylene reduction in submerged soil increased after addition of cellulose. Non‐flooded conditions favoured N2‐fixation in the fertile clay soil amended with sucrose.
Distribution and decomposition pattern of cutin and suberin in forest soils
Authors: Kögel‐Knabner Ingrid , Ziegler Frank , Riederer Markus , Zech Wolfgang 
Published: February 2007

AbstractThe composition and decomposition pattern of cutin and suberin in forest soils have been determined by chemical degradation (transesterification) and subsequent gaschromatographic analysis. Cutin and suberin are mainly confined to the forest floor horizons. With increasing soil depth an increasing contribution of suberin due to root litter is observed.
Zur Verwendung von Gesteinsmehlen in der Landwirtschaft. I. Chemisch‐mineralogische Zusammensetzung und Eignung von Gesteinsmehlen als Düngemittel
Authors: Blum W. E. H. , Herbinger B. , Mentler A. , Ottner F. , Pollak M. , Unger E. , Wenzel W. W. 
Published: February 2007

AbstractFünf Gesteinsmehle unterschiedlicher chemisch‐mineralogischer Zusammensetzung wurden bezüglich ihrer Eignung als Düngemittel in der Landwirtschaft untersucht.Die Nährelementwirkung der Gesteinsmehle wird vor allem von der mineralogischen Zusammensetzung und dem Vermahlungsgrad bestimmt, jedoch nur in geringem Maße von den Nährelementgesamtgehalten.Der geringe Gehalt verfügbarer Nährstoffe (unter 1%) und der hohe Anteil an für die Pflanzenernährung bedeutungslosen Stoffen (über 70% oxidisches Si, Al und Fe) stellen den Einsatz als Düngemittel, zumindest in annuellen Anbausystemen, in Frage.Die Unterschiede zwischen den untersuchten Gesteinsmehlen sind so groß, daß der Begriff “Gesteinsmehl” für sich allein keine Aussagekraft besitzt.
Modellanlage zur Bestimmung von Ammoniakverlusten aus organischen und mineralischen Düngern unter kontrollierten Bedingungen
Authors: Vilsmeier Klaus , Rank Martina , Amberger Anton 
Published: February 2007

AbstractEs wurde ein geschlossen‐dynamisches Modell mit kontinuierlicher Erfassung der Ammoniakverluste entwickelt.Das NH3, das von der Bodenoberfläche entweicht, wird in eine Säurevorlage eingeleitet. Der pH‐Anstieg entspricht dieser NH3‐Menge und wird mit einem Datenerfassungsgerät registriert.Die Windgeschwindigkeit ist im Bereich von 100 bis 400 1 Luft/h, das entspricht einem 12 bis 40‐fachen Luftaustausch/min, die Temperatur zwischen +5° und +30°C einstellbar. Darüberhinaus kann die Luftfeuchtigkeit gezielt reguliert werden.Die Prüfung des Modells ergab eine Abweichung von max. 0.6% zwischen pH‐Messung und Destillation.Die durchschnittliche Wiederfindungsrate betrug 97.2%.
Zum Einfluß von pH und organischem Kohlenstoffgehalt auf die Löslichkeit von Eisen, Blei, Mangan und Zink in Waldböden
Authors: Neite Heinz 
Published: February 2007

AbstractZahlreiche Bodenfaktoren bestimmen die Löslichkeit von Schwermetallen in Böden. Der pH‐Wert und der Gehalt an organischem Kohlenstoff beeinflussen in erster Linie die Gehalte austauschbarer und damit potentiell pflanzenverfügbarer Schwermetalle.Aus der Bestandesmitte und den vom Stammablaufwasser der Buchen beeinflußten Bodenbereichen wurden Proben aus dem Ah‐Horizont in Buchenwäldern untersucht. Die Löslichkeit von Eisen, Blei, Mangan und Zink wird in Abhängigkeit vom pH‐Wert und dem Gehalt an organischem Kohlenstoff dargestellt. Die Ergebnisse zeigen, daß höhere austauschbare Eisen‐ und Bleigehalte, unabhängig vom Gehalt an organischem Kohlenstoff, erst bei pH‐Werten unter 3.5 bzw. 4.5 nachweisbar sind. Mangan und Zink sind dagegen schon bei pH‐Werten unter 5.0 austauschbar und werden bei pH‐Werten unter 3.0 zu über 90% aus dem Ah‐Horizont ausgewaschen. Die Auswirkungen hoher löslicher Eisen‐ und Bleigehalte auf die Ausbreitung krautiger Pflanzenarten werden diskutiert.
Osmotic potentials and solute concentrations in sugar beet plants cultivated with varying potassium/sodium ratios
Authors: Lindhauer Meinolf G. , Haeder Hans E. , Beringer Helmut 
Published: February 2007

AbstractCell saps from leaves, petioles and storage root of sugar beet plants were analysed to indicate the possible specific and/or non‐specific (osmotic) function of K and Na ions for the regulation of assimilate partitioning in sugar beet. Plants were cultivated up to 94 days in nutrient solutions containing either 4.5 mol m−3 K + 0.5 mol m−3 Na (K plants) or 0.5 mol m−3 K + 4.5 mol m−3 Na (Na plants) or 0.5 mol m−3 K + 0.5 mol m−3 Na (control). Osmotic potentials of the cell sap of leaf blades (−1.4 to −1.6 MPa) and petioles (−1.6 to −2.0 MPa), respectively, were rather low and similar. It was concluded that in these organs Na may replace K in its osmoregulatory functions. While shoot growth was favoured by Na, a principally improved translocation of K into the taproot was noted. This was ‐ especially in the K‐treatment ‐ associated with increased growth of the storage root and a simultaneously stimulated sucrose accumulation. The results are discussed in terms of a different compartmentation of K, Na and Cl within the cell and within the whole plant and of a specific role of potassium in the process of assimilate translocation and storage.