bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zur Feldspatverwitterung und ihrer Bedeutung für die Tonmineralbildung
Authors: Bronger A. , Kalk E. 
Published: February 2007

Weathering of feldspars and their importance for the formation of clay mineralsIn quaternary sediments weathering and transformation of layer silicates, and in particular of biotites play a dominant role in the formation of clay minerals in soils of the moderately (semi) humid climate. In contrast, conflicting results were published concerning the participation of feldspar weathering for pedogenetic clay mineral formation. Another question is, whether formation of clay minerals in the fractions 0,6–0,2 μ m and<0,2μ m by chemical weathering of micas and feldspars is the dominating process, or the formation of „pseudo clay minerals”︁ in the fraction 2–0,6 μ m by cryoclastic desintegration of micas and feldspars, as proposed by several authors. It is not yet clear, which clay minerals are formed from the weathering products of feldspars. — A necessary condition for a conclusive study of these problems is the vertical sedimentary homogeneity of the soil forming material.In eight loess soils investigated of very different genesis (a syrosem, chernozems, brown forest soils and a „braunlehm”︁) there were no indications for clay formation in the coarse clay fraction (2–0,6μm) by physical weathering of feldspars. This was also true for the loess‐syrosem of young Würm age, where the former climatic conditions should have promoted this process.In the chernozems, the brown forest soils and the braunlehm the proportion of illite and Smectite newly formed were about 25–40% and 45–50% respectively. They are derived mainly from layer silicates but also from feldspars. In the chernozems 15–20%, the recent brown forest soils 20–25%, in a brown forest soil from the last interglacial period more than 30% and in the braunlehm of middle pleistocene age more than 40% of the original feldspars were destroyed by chemical weathering and had participated in clay formation, especially in the formation of smectites.
Umwandlungen von Dreischichtsilikaten unter K‐Abgabe und K‐Aufnahme
Authors: Niederbudde E. A. 
Published: February 2007

Transformation of three‐layer silicates through K‐release and K‐uptake (A review).In soils formed from unconsilidated sediments with illite‐vermiculite‐smectite mixtures in their clay fractions the clay mineral transformation from illite to vermiculite and smectite between pH 5 and 7 cannot be considered so far as proven on the grounds of available analytical data. Studies of soil profiles showed that the formation of illite from expandable three layer silicates predominates over the formation of smectite from illite. Practically all samples of loess and calcareous tills of the areas discussed contain smectites. K loesses between pH 5 and 7 are probably very small, because K released during the formation of vermiculites from micas is immediately fixed by smectitic layers which are converted to illite. In those soils potential K fixation of the clay fraction (« 2 μ) is lower than in the corresponding parent sediments despite of vermiculite formation in the soils. Further analytical data (X‐ray, interlattice‐K, K‐selectivity, specific surface) support the hypothesis of illitization of smectites during soil formation.
Bildung und Eigenschaften amorpher Tonbestandteile in Böden des gemäßigt‐humiden Klimabereichs
Authors: Gebhardt H. 
Published: February 2007

Formation and properties of amorphous clay constituents in soils of the temperate‐humid climate regionA review of literature and of some own work was given on formation and properties of amorphous clay constituents which occur along with crystalline clay minerals in soils. By that the importance of soil amorphous material with respect to pedologic‐agricultural and social‐environmental problems was tried to emphasize.At the beginning some clarification of the different terms used for inorganic amorphous clay constituents and a sort of difinition of the different kinds of amorphous materials seemed to be evident. Then, the occurence and the formation of amorphous material in soils of the temperate‐humid climate region was commentated. As a result of this it was stated that amorphous clay constituents occur mainly as coatings on negatively charged surfaces of crystalline layer silicates. From the grouping of amorphous substances around negatively charged cores (layer silicates or AlIV‐cores in allophanic soils, respectively) it was deduced that the organisation of amorphous clay constituents and allophanes as well as synthetic aluminosilicates might be due to an unique structural principle, which was tried to explain more detailed.The methods used for determination of amorphous materials, especially allophanes, were discussed. Since the determination of amorphous clay constituents by chemical dissolution techniques is ambiguous with respect to soils containing different weathering stages of crystalline layer silicates as well, some suggestions were made for characterizing amorphous substances in soils by cation exchange and anion adsorption properties. Finally the importance of exchange‐reactions caused by specific adsorption of ions and molecules (e.g. nutrients and pesticides) was indicated. Furthermore, the possibility was mentioned that harmful environmental substances might be bound (neutralized) and waste nutrients might be recycled by specific adsorption on amorphous soil constituents.
Bestand, Umwandlung und Neubildung von Tonmineralen in küstennahen Sedimenten der Nordsee
Authors: Brümmer Gerhard , Schroeder Diedrich 
Published: February 2007

Content, Transformation and Neoformation of Clay Minerals in near shore Sediments of the North SeaFrom literature and our own results, approximate quantitative values are given on the mineral content of clay and silt fractions of marine sediments from the Wadden Sea. Besides this, the extent of clay mineral transformation and neoformation in a marine environment is discussed.According to our knowledge, the extent of clay mineral transformation and neoformation must be unimportant because the sea water and pore solution of the sediments seems to be ‐ with the exception of a small Mg‐surplus — something like an equilibrium solution for three‐and fourlayer minerals, which neither favors a considerable base fixation nor base release. Therefore illite neoformation during halmyrolysis or early diagenesis seems to be impossible because of unfavourable relations of potassium to all other cations in the sea water. Obviously the neoformation of illite is connected with later diagenesis. The processes of clay mineral neoformation in a marine evironment are probably restricted to the formation of amorphous (Mg‐) Fe‐Si‐particles, which may be first steps in the formation of chamosites, chlorites or smectites.
Elektrochemisches Verhalten harnstofflöslicher Komponenten von Weizenkleberproteinen
Authors: Günzel G. 
Published: February 2007

Electrochemical Behavior of Urea Soluble Components of Gluten Proteins of WheatProtein zones of urea soluble gluten proteins of wheat samples from different cultivars and locations were analyzed after 2 dimensional separation by sucrose‐density‐gradient isoelectric focusing and disk polyacrylamide‐gel electrophoresis.More than 50% of the urea soluble proteins was focused in a range from pH 6,5–7,6. The major concentration in all samples was observed close to pH 7,0 as indicated by the main peak in all absorption diagrams.Electrophoretic separation of proteins of equal isoelectric characteristics yielded fractions differing mainly in charges.Two dimensional separation yielded more than 40 protein fractions. The pattern of these fractions was more influenced by environmental effects than by cultivars. No relation between protein pattern and baking quality was observed.
The physiology of salt injury in plant production
Authors: Oertli J. J. 
Published: February 2007

Die Physiologie der Salzschädigung in der PflanzenproduktionDas Pflanzenwachstum bei verschiedener Salinität wird an einem Modell der Zellstrekkung untersucht. In diesem Modell wird angenommen, daß die Geschwindigkeit der Zellstreckung durch die Produktion von Osmolalität in der Zelle via Stofftransport begrenzt wird. Eine osmotische Anpassung, d.h. konstanter Turgordruck, wird vorausgesetzt.Modell und Beobachtungen stimmen in folgenden Punkten überein: a) Es gibt eine optimale äußere Lösungskonzentration, bei der die Zellstreckungsrate maximal ist, b) bei hohen Salzkonzentrationen nimmt die Zellstreckungsrate trotz osmotischer Anpassung ab, c) niedere (stark negative) Wasserpotentiale, die durch nicht aufnehmbare Osmotika (oder durch eine Matrix) verursacht werden, reduzieren immer die Zellstreckungsrate, d) in Mischlösungen verschieben die nicht aufnehmbaren Osmotika die Optimumkonzentration aufnehmbarer Osmotika zu höheren Werten. Die Zellstreckungsraten werden dabei aber kleiner. e) Schnelle Stoffaufnahme bedeutet größere Produktion von Osmolalität im Zellsaft und fördert dadurch die Zellstreckung. b) Während des nicht stationären Zustandes, der auf eine Versetzung von Geweben aus verdünnten in mehr konzentrierte Lösungen folgt, verschiebt sich das Optimum allmählich zu höheren äußeren Konzentrationen.Stoffaufnahme und Auxinwirkung zeigen verschiedene pH Optima bei der Zellstreckung. Die Zellstreckungsrate wird durch das pH Optimum der Stoffaufnahme dominiert außer in Anfangsstadien.Die Teilungsrate von Scenedesmus quadricauda zeigt ebenfalls eine optimale äußere Konzentration. In konzentrierten Lösungen werden weniger, dafür aber größere Zellen gefunden.
The role of magnesium in plant nutrition
Authors: Kirkby E. A. , Mengel K. 
Published: February 2007

Die Rolle des Magnesiums in der PflanzenernährungIn dem Beitrag wird die Bedeutung des Mg in der Pflanzenernährung diskutiert. Er behandelt den Boden in seiner Eigenschaft als Mg‐Quelle der Pflanze. Aufnahme und Verteilung von Mg in der Pflanze, physiologische Funktionen des Mg, Mg‐Mangel und die Rolle des Mg bei der Ernährung von Kulturpflanzen.
Einfluß einer Stickstoff‐Spätdüngung auf das Korneiweiß einer lysinreichen Maishybride
Authors: Zink F. , Wilberg E. 
Published: February 2007

Effect of Late Application of Nitrogen on the Grain Protein of a Maize Hybrid Rich in Lysine1. In pot experiments the influence of an additional late N fertilizer application at time of flowering on a high yielding lysine‐rich experimental maize hybrid has been determined.2. N‐fertilization at flowering increased the total‐N and the lysine‐contant of the grains. The lysine‐N in % of total‐N was constant at 5,1%. Comparable values from a former investigation with an opaque‐ and a standard hybrid are 6,0% lysine‐N and 4,0% lysine‐N of total‐N, respectively.3. The ratio of prolamine to gluteline was 1:1. N‐fertilization did not change this ratio.4. The amino‐acid pattern of the single protein fractions, albumine globuline, prolamine and gluteline was very different, but it was not changed by N‐fertilization.5. Dissecting embryo and endosperm, demonstrated that by late N‐fertilization the growth of embryo was promoted more than that of the endosperm. The embryo contributed 30% to total‐N and 44% to total‐lysine‐N of the grain and was not changed by the late N‐application.6. At cultivating such improved hybrids it may be expected that the protein quality will not be changed by application of high amounts of N‐fertilizer, whereas the protein quantity will be increased.
Aufnahme und Verteilung von 15N‐markiertem Harnstoff bei Phaseolus vulgaris L
Authors: Hentschel G. 
Published: February 2007

The Uptake and Distribution of 15N‐Labelled Urea by Phaseolus vulgaris LThe uptake of two‐fold 15N‐labelled urea via the root system of 21 days old plants of Phaseolus vulgaris in comparison with 15N‐marked ammonium chloride has been investigated. The concentration of urea or ammonium resp. was 3 mmol/l. The plants were allowed to take up the labelled nitrogen for an 8 hours period. The determination of the 15N‐frequency was carried out by emission spectrometry.The results demonstrate that urea is taken up as a whole undestructed molecule. Also there is evidence for a 7‐fold enrichment of urea in the exsudation sap in comparison with the urea concentration in the nutrition solution. Inhibition of the metabolic activity of the roots (2,4‐DNP, KCN, AsO4, N2) reduces both the urea and the ammonium absorption to a considerable rate. Variations of the transpiration, of the Ca/K ratios or pH in the nutrition solution have none or only a very small influence on the uptake of urea. There may be the possibility for the existence of a common mechanism for the absorption of both urea and ammonium.
Untersuchungen zur Bedeutung des Ernährungszustandes von Kulturpflanzen für ihre Salztoleranz
Authors: Schleiff U. , Finck A. 
Published: February 2007

Investigations on the significance of the nutritional status of plants for their salt toleranceIn order to explain the causes of salt damages on crops in the Sibari Plain (Southern Italy) the nutrient contents of plants were used in addition to soil data.Increasing Na‐ and Mg‐salinity reduced the K‐contents of wheat plants during sprouting below the (preliminary) critical value of 30%o and the Ca‐contents below the value of 3%o in spite of high gypsum contents and optimum K‐supply of the soils (compared to soils with low salt contents). The content of nutrient elements can be improved by an increased nutrient supply up to the optimum range, and the content of detrimental elements in plants can be reduced below toxic limits. The specific toxicity of Mg‐salts (believed to be especially high) could be prevented by optimum nutrition of the plants until general salt effects became dominant factors of damage.At optimum nutrient supply 6–7%o Mg in the tops of corn plants were toxic in greenhouse experiments. In the field even at high Mg‐supply of the soils no more than 2,5%o Mg were found in cereals. At optimum K‐supply more than 1–2%o Na in wheat plants reduced the yield.The salt tolerance of plants, therefore, can be increased by proper fertilisation.
Der Einfluß von Ancymidol und Ethrel auf den Gibberellinsäuregehalt (GA3) von Getreidepflanzen
Authors: Sadeghian E. , Kühn H. 
Published: February 2007

Influence of Ancymidol and Ethrel on the synthesis of gibberellic acid (GA3) in cereal plants.In pot experiments with oat, barley and rye both growth regulators Ancymidol and Ethrel considerably reduced the GA3 content in the 3 plant species. Ancymidol was approximately 10 times more effective than Ethrel. This higher effectivity of Ancymidol on the GA3 content and the different structure of the Ancymidol molecule compared to Ethrel makes it probable that Ancymidol inhibits the GA synthesis in a different way than Ethrel (or CCC).Although Ethrel was less effective in reducing the GA content it decreased the stalk length more than Ancymidol. It is concluded that Ethrel not only influences the GA induced growth but also other processes which regulate the length growth of plants.
Bodenhydrologische Methoden zur Untersuchung ungestörter, skelettreicher Böden
Authors: Benecke P. , Beese F. , van der Ploeg R. R. 
Published: February 2007

Soil hydrological methods for investigations on undisturbed samples of skeleton‐rich soilsNew methods are proposed, which allow the determination of moisture transmission properties of stony soils. A soil sampling technique is discussed whereby small monoliths are isolated from the surrounding soil and covered with polyester‐soaked glassfiber sheets. With use of such irregularly shaped columns the soil moisture characteristic and the unsaturated hydraulic conductivity are determined by laboratory procedures. Starting with a saturated column, suction is applied and the resulting outflow is measured. At the same time the suction in the sample is registered and also the hydraulic gradient within the sample is determined.Also discussed is a procedure to install tensiometers in stony soils. The installation provides reliable data and the maintenance is easy. By building in a heating system in the tensiometers, these can be operated all year round.
Quantitative Erfassung der reduzierten Substanzen in Unterwasserböden
Authors: Fischer W. R. , Baumann G. 
Published: February 2007

Quantitative determination of reduced substances in subhydric soilsThe determination of reduced substances is possible by rapid oxidation with a diluted potassium dichromate/sulfuric acid solution at room temperature, and subsequent titration with FeSO4 solution. These values (meq/100 ml of fresh sample) show a nonlinear, negative correlation with redox potential, and increase with increasing content of organic material. Sulfides, expressed as FeS, amount to appr. 50 % of the reduction equivalents. Subhydric soils rich in nutrients show an increasing amount of reduced substances with increasing depth, whereas oligotrophic and mesotrophic soils give no distinct depth function.
Dissolution and plant uptake of P from Ca phosphates with varying particle size in two soils I. Dissolution studies
Authors: Metwally A. I. , Omar M. , El‐Baz S. 
Published: February 2007

Auflösung von Ca‐Phosphaten und P‐Aufnahme durch die Pflanze in zwei Böden bei unterschiedlicher Körnung dieser P‐Quellen. I. Auflösung der Ca‐PhosphateIn einem Alluvial‐ und einem Kalkboden wurde in Laborversuchen mit Hilfe von drei markierten Ca‐Phosphaten (MCP, DCPD u. HA) der Einfluß der Wasserlöslichkeit und der Oberfläche auf die Stabilität dieser Verbindungen untersucht.Mit abnehmender Teilchengröße von DCPD nahm der 32P‐Anteil im Boden, der mit 0.5 M KH2PO4 rücktauschbar war, relativ zu, während er bei HA sehr niedrig und nur wenig durch den Teilchendurchmesser beeinflußt war; bei MCP dagegen wurde der rücktauschbare Anteil höher mit zunehmender Größe des Düngerkorns. Zunehmende Bodenfeuchte und Temperatur steigerten das rücktauschbare 32P in allen Fällen, während es mit der Inkubationsdauer zwar bei DCPD erhöht, bei MCP jedoch gesenkt wurde. Nach 8 Wochen Inkubationszeit war zwischen pulverisiertem (« 0,18 mm) DCPD und MCP kaum mehr ein Unterschied zu bemerken. Im Kalkboden (stL, 0,9% org. S., 30,6% CaCO3, pH 8,5) war der rücktauschbare 32P‐Anteil bei allen P‐Quellen niedriger als im Alluvialboden (T, 1,2%org. S., 2,5% CaCO3, pH 7,8), weil hier pH‐Wert und CaCO3‐Gehalt tiefer lagen.Offensichtlich wurde der Anteil an rücktauschbarem 32P aus DCPD und HA vor allem durch deren Lösungsrate, der aus MCP dagegen durch dessen Immobilisierungsrate kontrolliert.
Cationic environment and hydrophysical properties of tropical soils
Authors: Rengasamy P. , Krishna Murti G. S. R. , Kathavate Y. V. 
Published: February 2007

Kationen‐Milieu und hydrophysikalische Eigenschaften tropischer BödenDer Einfluß eines wechselnden Kationen‐Milieus auf hydrophysikalische Eigenschaften (Wasserbindungen, hydraulische Leitfähigkeit, kapillarer Aufstieg und Infiltrationsverhalten) einiger tropischer Böden Indiens wurde untersucht. In den schwarzen Böden herrschte Smektit vor, in den lateritischen Kaolinit, während in den roten und alluvialen Böden Smektit und Kaolinit in gleichen Anteilen vorhanden waren. Folgende Kationen wurden untersucht: Na+, K+, Ca++, Mg++. Die Ergebnisse werden nachstehend zusammengefaßt: 1. Die genannten hydrophysikalischen Eigenschaften hängen hauptsächlich vom Bodentyp und insbesondere vom vorherrschenden Tonmineral ab. 2. Zweiwertige Ionen erhöhen die hydraulische Leitfähigkeit, den kapillaren Anstieg und die Infiltrationsrate; einwertige Ionen dagegen verursachen eine beträchtliche Reduktion. 3. Exponentielle Beziehungen zwischen austauschbarem Na (ESP) oder austauschbarem K (EPP) und der zugehörigen hydraulischen Leitfähigkeit wurde erhalten. Diese Beziehungen variieren mit den Böden und ihrer Tonmineralausstattung. Für Na und K wurde für alle Böden aufgrund der ESP‐ und EPP‐Werte ein kritischer Grenzwert gefunden, an dem die hydraulische Leitfähigkeit auf die Hälfte ihres ursprünglichen Wertes vermindert ist.
Outlines of a computer simulation model on residual and added nitrogen changes and transport in soils
Authors: Hagin J. , Amberger A. , Kruh G. , Segall E. 
Published: February 2007

Grundzüge eines Computersimulationsmodelles über die Veränderungen und den Transport von Boden‐ u. DüngerstickstoffEs wurde ein Computermodell entwickelt über die Veränderungen und den Transport von Stickstoff in Böden. Der theoretische Hintergrund und die notwendigen Annahmen für die Aufstellung eines solchen Programmes werden dargelegt. Die Umsetzungen von org. Stickstoff in Ammonium bzw. Nitrat sowie die Denitrifikation von Nitrat werden dargestellt als eine Reaktionsgleichung ersten Grades. Die Reaktionskonstanten und einige Parameter werden aufgezeigt und die Einflußgrößen der Umweltfaktoren auf die Reaktionsraten beschrieben. Das gebildete oder zugegebene Nitrat bewegt sich durch das Bodenprofil und kann verlorengehen durch Auswaschung, Aufnahme von Pflanzen bzw. immobilisiert oder denitrifiziert werden.
Einfluß exogener und endogener Faktoren auf den Calciumgehalt von Paprika‐ und Bohnenfrüchten
Authors: Mix G. P. , Marschner H. 
Published: February 2007

Effect of external and internal factors on the calcium content of paprika and bean fruitsIn water culture experiments with paprika and bean plants the effect of Ca supply, transpiration and growth rate on the Ca content of the fruits has been studied.A 10‐fold increase in Ca supply only slightly increased the Ca content. The Ca content of the paprika fruits was increased considerably at high transpiration rates of either the whole shoot or the single fruit. High transpiration also increased the Mg content but had no effect on the K content. In bean high transpiration rates only increased the Ca content in the early stages of fruit development.The ratio of Ca translocation versus water loss by transpiration sharply declined during fruit growth in both species. In paprika the highest ratio (μg Ca/ml) in the fruits corresponded with the ratio in the leaves. In bean fruits, however, this ratio distinctly exceeded that of fully developed leaves.At high transpiration rates of the shoot 20% of the Ca (45Ca) injected into the fruit were translocated out of the fruit. At low transpiration rates of the shoot the corresponding value was below 1%.Most of all the growth rate of the fruits affected the Ca content. With increasing growth rate the Ca transport into the fruits was hardly altered which in turn led to a sharp decrease of the Ca content per unit dry weight.The results support the idea of the Ca transport into the fruit via the xylem. This Ca transport — i.e. also the Ca content of the fruit — is regulated and is also to be influenced by direct or indirect alterations of the water transport in the xylem.
Ein Verfahren zur Bestimmung der Lagerungsdichte skelettreicher oder geringmächtiger Bodenhorizonte
Authors: Becher H. H. , Wilke B.‐M. 
Published: February 2007

A method for bulk density determination of gravel rich or thin soil horizonsA limitation of bulk density determinations using the core sample method is that soil horizons must be thick enough for coring and nearly free of rock material. The significance of the proposed method lies in the fact that it is applicable also to soil samples rich in rock fragments and/or thin horizons. The samples are impregnated in the laboratory using an epoxy resin. Bulk density (ρb) is determined after hardening according to the following equation:magnified imageρf = density of soil material Bulk densities determined by the new method were found to agree well with such resulting from the core sample method.