bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lignin signature of subalpine Rendzinas (Tangel‐ and Moderrendzina) in the Bavarian Alps
Authors: Kögel Ingrid , Ziegler Frank , Zech Wolfgang 
Published: February 2007

AbstractSimple phenolic lignin degradation products released from alkaline CuO oxidation are used to characterize the lignin component of a Tangelrendzina and a Moderrendzina. The sum of CuO oxidation products describes the overall lignin decomposition pattern. The ratio of acid/aldehyde of the vanillyl unit and the ratio of syringyl/vanillyl units give an indication of the alteration of the remnant lignin molecule.In both soils the sum of lignin oxidation products shows a pronounced decrease with depth. In the Oh, Ca horizon of the Tangelrendzina and the Ah of the Moderrendzina an accumulation of lignin‐derived phenolic compounds is observed. The strong increase of the acid/aldehyde ratio at the transition from the humus to the mineral horizons in both soils and the decrease of the syringyl/vanillyl ratio in the Moderrendzina demonstrate a considerable chemical alteration of the remnant lignin molecule (oxidation of side‐chain, enrichment with vanillyl units) with progressive decomposition and humification of litter material. The depth functions of the lignin parameters are influenced by decomposition of lignin, accumulation of water‐soluble lignin fragments and the input of root litter.
Einfluß langjähriger Gülledüngung auf den Nährstoffhaushalt des Bodens. 1. Mitteilung: N‐Akkumulation und N‐Nachlieferungsvermögen
Authors: Scherer Heinrich W. , Werner Wilfried , Kohl Andrea 
Published: February 2007

AbstractIn der vorliegenden Arbeit wurde der Einfluß der Gülledüngung im Vergleich zur Mineraldüngung auf den Stickstoff‐Haushalt und das Stickstoff‐Nachlieferungsvermögen von 3 Lößparabraunerden bis in 90 cm Tiefe untersucht.Folgende Ergebnisse wurden erzielt:
– Langjährige Gülledüngung resultierte in einem Anstieg des Gesamt‐N‐Gehaltes nicht nur in der Krume sondern bis in die Schicht 60–90 cm.
– Der Anstieg des Gesamt‐N‐Gehaltes ist in 2 Böden sehr deutlich auf die hydrolysierbaren organischen N‐Verbindungen und in dem Boden mit der absolut geringeren N‐Anreicherung auf die nicht hydrolysierbaren organischen N‐Verbindungen zurückzuführen.
– Der Einfluß der Gülledüngung auf die Gehalte an spezifisch gebundenem NH4+ erwies sich als von der K‐Absättigung der Tonminerale abhängig.
– Im Bebrütungsversuch zeigten die begüllten Böden sowohl zu Beginn als auch am Ende der Vegetationsperiode bis in die Tiefe von 90 cm ein signifikant höheres N‐Mineralisierungsvermögen.
– Zwischen dem N‐Nachlieferungsvermögen und dem Gehalt an hydrolysierbaren organischen N‐Verbindungen bzw. der mittels EUF ermittelten Norg‐Fraktion besteht eine hoch signifikante Korrelation.
– Langjährige Gülledüngung führte erwartungsgemäß während der gesamten Vegetationsperiode zu höheren Nmin‐Gehalten.
Zum Vergleich von Penetrometermessungen, durchgeführt bei unterschiedlichem Wassergehalt
Authors: Borchert Heinz , Graf R. 
Published: February 2007

AbstractMit Hilfe einer großen Zahl von Geländemessungen wurde eine empirische Beziehung zwischen Bodenwassergehalt und Penetrometerwiderstand hergeleitet. Die untersuchten Böden wurden dabei unterteilt aufgrund der Bodenart und der Rohdichte. Die gezeigten Kurven ermöglichen einen Vergleich von Penetrometermessungen, welche bei unterschiedlichem Bodenwassergehalt durchgeführt wurden.
An Improved Turbidimetric Estimation of Total Sulfur in Plant Samples
Authors: Mathur P. N. , Sharma D. D. , Jain G. L. 
Published: February 2007

AbstractThe estimation of total sulfur content in plant samples by the nitric acid‐perchloric acid wet oxidation, when used with the Tabatabai and Bremner's adaptation of the Barium chloride‐gelatin method of Dodgson, gives lower results as compared to the magnesium nitrate oxidation, particularly for samples low in sulfur content. For samples containing relatively high sulfur content, both methods of oxidation give comparable results.
Investigation on the Stabilization of the Humus in Mollisols
Authors: Tsutsuki Kiyoshi , Suzuki Chikage , Kuwatsuka Shozo , Becker‐Heidmann Peter , Scharpenseel Hans‐Wilhelm 
Published: February 2007

AbstractSoil organic matter in Mollisols is often preserved for an extremely long period (e.g. > 3000 years). We confirmed that the stable organic matter in Mollisols is the medium to coarse sized (0.2–2.0 μm) clay‐humus complex with humic acid combined with calcium as the main organic constituent. The argillic horizon contained relatively large amounts of clay‐humus complexes and had relatively high carbon contents, humic acid/fulvic acid ratios and degrees of humification of humic acid. Medium clay and coarse clay fractions preserved the organic carbon most efficiently. Highly humified humic acid could be detected even in the uppermost part of the Ah horizon and was probably stabilized in lower horizons by forming a complex with clay fractions.
Spatial variability of groundwater solute concentrations at the water table under arable land and coniferous forest. Part 3: Field data for a coniferous forest and statistical analysis
Authors: Böttcher Jürgen , Strebel Otto 
Published: February 2007

AbstractThe spatial variability of groundwater solute concentrations at the water table beneath a fine to medium sandy soil (Gleyic Podzol) under a 45‐years old pine stand was investigated. Samples were taken within the first decimeter below the groundwater table at horizontal intervals of 0.5 m along a 30 m transect in between two rows of trees. Nitrate, sulfate, and aluminum concentrations and pH were determined and analyzed by geostatistical and spectral analysis methods.Semivariance analysis shows spatial dependence in the data (except for nitrate) up to ranges of between 1.7 and 3 m. Spectral analysis indicates periodic variations with a period of 4 ‐ 5 m. The periods for sulfate and aluminum are synchronous and 180° out‐of‐phase with the pH curve. The sulfate and aluminum maxima and pH minima correspond to areas within edges of the tree canopies (canopy drip). Differences in the acid input into the weakly buffering soil caused by the interception deposition of atmospheric constituents at the canopy result in a regular pattern in the concentrations of certain solutes in the uppermost groundwater. The variogram and spectrogram of the nitrate concentration indicate the presence of a trend. The cospectrogram for nitrate and pH has a peak that corresponds to synchronous short‐range (about 2 m) variations, i.e. a small‐scale correlation between nitrate concentration and pH.
Effect of the herbicide MCPA on VA mycorrhizal infection and growth of Pisum sativum
Authors: Garcia‐Romera Inmaculada , Ocampo Juan A. 
Published: February 2007

AbstractThe effect of the hormonal herbicide MCPA on VA mycorrhizal infection and on pea plant growth was examined. Plant growth was decreased by MCPA applied at the rate of 120 ppm. The VA infections of pea roots inoculated with G. mosseae was decreased by the MCPA when applied at high dosis (120 ppm), but those of indigenous endophytes were decreased at the rate of 12 and 120 ppm. MCPA applied to VA inoculated pots eight weeks before pea planting also decreased the VA infection of these plants. These results suggest that VA mycorrhizas was affected not only through the plant but also directly by the application of the herbicide.Glomus mosseae may help plants recover from the deleterious effect of MCPA when applied at intermediary (12 ppm) but not at high dosis (120 ppm).
Einige Bemerkungen zur Bestimmung der Wasserleitfähigkeit mit der Bohrlochmethode
Authors: van der Ploeg Rienk R. , Huwe Bernd 
Published: February 2007

AbstractMit der Bohrlochmethode erzielte Leitfähigkeitswerte können, in Abhängigkeit von der benutzten Rechenprozedur, variieren. In der vorliegenden Arbeit werden mit dem Verfahren von Ernst (1950) errechnete Werte verglichen mit Werten, die mit der Methode von Boast und Kirkham (1971) erzielt wurden. Unterschiede von mehr als 25 Prozent wurden festgestellt. Daraus wird geschlossen, daß Vorsicht angebracht ist bei der Berechnung von Leitfähigkeitswerten nach der Bohrlochmethode. Das Verfahren von Boast und Kirkham (1971) erscheint am zuverlässigsten.
Nitrifikation von Gülle‐N in Abhängigkeit von Ausbringungstermin, pH‐Wert des Bodens und Dicyandiamidzusatz
Authors: Amberger Anton , Vilsmeier Klaus 
Published: February 2007

AbstractIn Modellversuchen wurde die Nitratbildung nach Gülledüngung in Abhängigkeit vom pH‐Wert des Bodens und Dicyandiamidzusatz unter simulierten Freilandtemperaturen von Oktober bzw November bis Juli untersucht.Im Boden mit pH 5.7 war ein Zusatz von 20 mg/kg DCD zu im Oktober ausgebrachter Gülle ausreichend, um die erst im März beginnende Nitrifikation sehr deutlich zu reduzieren.Im Boden mit pH 7.2 wurde die vor Winter bereits größtenteils ablaufende NO3‐Bildung durch 20 mg/kg DCD bis April/Mai verzögert. Höhere DCD‐Mengen bewirkten eine weitere Verzögerung um ca. einen Monat.Nach Gülledüngung Ende November (Bodentemperatur 0°C) wurde die Nitrifikation durch den Dicyandiamidzusatz um bis zu 3 Monate verzögert.
Note on the genesis and ecology of “White Pulp Soils” in NE‐ China
Authors: Rong‐ji Xia , Schlichting Ernst 
Published: February 2007

Abstract“White Pulp Soils” are eutric Planosols, their permeability profile being caused more by stratification than by lessivage and most likely not by ferrolysis. For climatic reasons their water/air regime differs very much from many other surface water soils, dry periods being more typical for the early and wet ones for the late summer. This may influence the diagnostic weight of the profile morphology and the transferability of ecological threshold values from stagnosols of other regions.
Chemical composition of the organic matter in forest soils: The humus layer
Authors: Kögel‐Knabner Ingrid , Zech Wolfgang , Hatcher Patrick G. 
Published: February 2007

AbstractDecomposition and humification were studied within three types of forest humus (mull, moder, and mor) by means of CPMAS13C NMR spectroscopy combined with degradative methods. The NMR data show that O‐alkyl carbon decreases in all soils, and alkyl as well as carboxyl carbon increase as depth and decomposition increase; the percentage of aromatic carbon remains constant at about 25%. With increasing depth the amount of carbon that can be identified as belonging to specific compound classes by wet chemical methods decreases from 60% to 40%. Microbial polysaccharides and the proportion of non polysaccharide O‐alkyl carbon increase with depth. A selective preservation of recalcitrant, condensed lignin structural units is also observed.In order to relate the spectroscopic and chemical data from investigations of whole soils with studies of humification, samples were fractionated into fulvic acid, humic acid, and humin fractions. The fulvic acid fraction contains large concentrations of carbohydrates irrespective of the soil horizon. The humic acid fraction contains less polysaccharides, but high amounts of alkyl carbon and aromatic structures. The percentage of aromatic carbon existing in the humic acid fraction increases with depth, probably reflecting the amount and degree of oxidative decomposition of lignin. A loss of methoxyl and phenolic groups is evident in the13C NMR spectra of the humic acid fraction. The humin fraction resembles relatively unchanged plant‐derived materials as evident from the lignin parameters and carbohydrate contents. All the observed data seem to indicate that humic acids originate form oxidative degradation of humin or plant litter.
Influence of prolonged use of sewage effluent in irrigation on heavy metal accumulation in soils and plants
Authors: Aboulroos S. A. , Holah Sh. , Badawy S. H. 
Published: February 2007

AbstractTotal content of Fe, Mn, Zn, Cu, Pb, Cd, Ni and Co in soils irrigated with sewage effluent increased with increasing years of using sewage effluent in irrigation. Iron and Co applied to the soil from sewage effluent were immobilized mainly in unavailable form; Pb, Cd, and Ni in moderately available form; and Mn, Zn, and Cu in highly available form. The concentrations of Fe, Mn, Zn and Cu in tops of alfalfa and leaves of corn grown on these soils increased substantially with increased levels of available metal content of the soil, while those of other metals were little affected. As for orange, continuous increase in leaves metal content with time was found for Fe, Mn, Zn, Co and Cd. The concentrations of Cd, Co, Ni and Pb in corn grains and orange fruits were several times higher than normal, and this reduces their suitability for human consumption.
Greenhouse Study on the Effects of the Urease Inhibitors Phenyl Phosphorodiamidate and N‐(n‐butyl) Thiophosphoric Triamide on the Efficiency of Urea Applied to Flooded Rice
Authors: Byrnes Bernard H. , Gutser Reinhold , Amberger Anton 
Published: February 2007

AbstractUrea was split applied to transplanted rice in a greenhouse experiment with two‐thirds applied as labeled15N urea at 15 days after transplanting (DAT) and one‐third (not labeled) at 42 DAT to determine the effect of the urease inhibitors phenyl phosphorodiamidate (PPDA) and N‐(n‐butyl) thiophosphoric triamide (NBPT) on urea hydrolysis, plant uptake, yield, and loss of fertilizer N. An acidifying agent [Al2(SO4)3] and an algicide were used to reduce the floodwater pH and thus slow the degradation of PPDA, keeping it effective for a longer period. Algicide addition extended the effectiveness of PPDA inhibition by about 2 days and increased plant uptake and grain yield significantly over that with urea use alone. Al2(SO4)3addition extended the effectiveness of PPDA only about 1 day, increased N uptake slightly, but failed to increase grain yield. NBPT effectively slowed urea hydrolysis, more than doubled plant uptake over that with urea alone, and increased grain yield by 38%. Percolation at 0.5 cm per day caused plant N uptake to increase by about 6% in all treatments but it was not essential for the inhibitors to have a beneficial effect. For the first split application, fertilizer losses of 50% from urea were decreased to about 10% by use of NBPT and to 28% with PPDA alone, and by combination of PPDA with the algicide losses were 22%.
Nitrogen supply to cereals and sugar beet by mass flow and diffusion on a silty loam soil
Authors: Strebel Otto , Duynisveld Wilhelmus H. M. 
Published: February 2007

AbstractIn a four‐year field study the nitrogen supply by mass flow and diffusion to cereals (spring wheat, winter barley, winter wheat) and sugar beet was investigated on a silty loam soil. The rates of water withdrawal, N mass flow and N diffusion were determined as a function of soil depth and time.The contribution to the N supply to roots by mass flow was 15–33% and mainly confined to the topsoil layer. The N supply by diffusion plays with 67–85% the dominant role, particularly in deeper rootzone layers. During periods of high N uptake, the N inflow (per unit root length and time) ranges between 0.26–2.07 μmol/(m · d) at various rootzone layers for cereal, and between 3.80–8.98 μmol/(m · d) for sugar beet, respectively. As a consequence of the high proportion of diffusion supply, at harvest the whole rootzone was largely depleted of nitrate. Thus, nitrate leaching losses during winter were small, the average nitrate concentration of the yearly groundwater recharge being only 7.9 mg N/l.Additionally, some results on supply of K, Ca, Mg and Cl for spring wheat and sugar beet are given. Diffusion supply prevails for K, and in the case of sugar beet for Mg and Cl also. Mass flow of Ca exceeded uptake considerably.
Mobilization and turnover of soil phosphorus in the rhizosphere
Authors: Helal Helal M. , Dressler Arthur 
Published: February 2007

AbstractRecent progress in methods enables a better understanding of the turnover of P in the rhizosphere. Examples of this progress are the separation of soil layers differing in proximity to the roots, improved methods for extraction and fractionation of soil P, application of 32P isotope dilution analysis to follow P fluxes between various fractions and direct determination of microbially bound P and of root phosphatases.
These methods were combined to investigate the following aspects
–labile P pools, the P fluxes between these pools and their contribution to the P supply to growing maize roots
–the role of microbial biomass in these interactions and the partition of mobilized P between plants and microorganisms
–modifications of sorption and transport of P in the rhizosphere
–plant availability of native and added organic phosphates, and the relative significance of root and soil phosphatases.
There is a significant transformation of P in the rhizosphere with a corresponding redistribution among fractions of different plant availability. About 9% of the inorganic 32P added to soil were incorporated within 2 weeks into microbial and organic fractions. The transfer of P from non‐exchangeable forms exceeded the depletion of the exchangeable P by a factor of 5. About 53% of the mobilized P originated from inorganic, the remaining 47% from organic fractions. Of the mobilized P 80% was taken up by the plants and 20% was found in the microbial biomass. Up to 90% of the P in the rhizosphere soil solution was organic with a maximum just outside the root zone. Soluble inositol hexaphosphate modified the sorption of inorganic P, thus shifting its equilibrium solution concentration. The phosphatase activity of the roots is considerable. Both root phosphatase activity and the utilization of inositol hexaphosphate depend on the P supply and nutritional status of plants with regard to P.It is concluded that the rhizosphere is a key site of P transformation with a significant mobilization of P from the non‐exchangeable inorganic and organic fractions. Organic P fractions not only play a significant role as a P source but also modify important soil parameters related to the sorption and transport of P in the rhizosphere.
pH values and redox potentials in microsites of the rhizosphere
Authors: Fischer Walter R. , Flessa Heiner , Schaller Günther 
Published: February 2007

AbstractRedox potentials (Eh) and pH values in the rhizosphere 0–2 mm from growing roots of field beans (Vicia faba L.) indicated reducing conditions near the root tip and along the zone of elongation which were probably caused by root exudates. For roots of other plant species (e.g. maize), a drop of Eh in the rhizosphere does not necessarily reflect reduction processes, but may be due to pH changes, according to the Nernst equation. Eh values near dying roots decreased due to the O2 consumption by microorganisms, this effect being detectable at a distance greater than 3 mm from the root surface.
Plant nutritional and soil factors in relation to microbial activity in the rhizosphere, with particular emphasis on denitrification
Authors: Trolldenier Günter 
Published: February 2007

AbstractExamples of the effect of mineral nutrition of plants (N, P, K, Mg, Fe) on microbial activity in the rhizosphere are presented with emphasis on our own studies related to root exudation, bacterial numbers, oxygen consumption and denitrification. Direct effects concern changes of pH, e.g. by liming. As the microbial community in the rhizosphere depends on decomposable organic substances released from roots, plant nutrition also indirectly affects microbial activity via its influence on plant metabolism and growth. Important factors affecting denitrification in the rhizosphere are, besides stimulation of denitrifiers by root exudation, air‐filled porosity and readily decomposable organic matter content of the soil.
Hormonal interactions in the rhizosphere of maize (Zea mays L.) and their effects on plant development
Authors: Müller Martin , Deigele Claudia , Ziegler Hubert 
Published: February 2007

AbstractThe phytohormones indole acetic acid (IAA), abscisic acid (ABA), isopentenyladenosine (iPA), dihydrozeatin riboside (DHZR), and zeatinriboside (ZR) were determined quantitatively using monoclonal antibodies by an enzyme immunoassay in the following samples: a) culture filtrates of known bacterial species, growing naturally in close, loose or without contact with higher plants; b) culture filtrates of heterogeneous populations of microorganisms, isolated from the rhizoplane and rhizosphere of maize as well as from root‐free soil; c) sterile and nonsterile maize root exudates; d) in the rhizosphere of field‐grown maize plants and in soil fractions distant from the roots (bulk soil).ABA was not detected in the culture filtrates of bacteria and ZR was not found in bulk soil and rhizosphere soil of field‐grown maize. All phytohormones were present in the other samples analyzed. Bacterial cultures with cell concentrations roughly equal to those in the rhizosphere of field‐grown maize may produce under optimal laboratory conditions phytohormone concentrations comparable to those measured in the rhizosphere of field‐grown maize. During the whole vegetation period there was a steep phytohormone gradient in the first centimeter of soil around a maize root in the field. Inoculation of maize seedlings growing in nutrient solution with rhizosphere bacteria resulted in a synergistic increase in phytohormone concentration in comparison to the sum of hormone production by sterile plant roots and by bacteria cultures.Using regression analysis, the relationship between phytohormone concentration changes in the rhizosphere and different morphological characteristics of the maize plant were shown to be highly significant.
Carbon and nitrogen mineralization of white clover plants (Trifolium repens) of different age during aerobic incubation with soil
Authors: Kirchmann Holger , Bergqvist Roger 
Published: February 2007

AbstractA 4‐month aerobic incubation experiment was conducted measuring carbon and nitrogen mineralization from white clover in soil at 25°C and optimal moisture conditions. Cumulative carbon mineralization from clover followed a double exponential function and was similar for tops and roots amounting to 77.5% of non‐lignin carbon initially present. Rate constants for the rapidly and slowly mineralized carbon fractions amounted to 0.21 d−1and 0.02 d−1respectively and were identical for tops and roots. Cumulative mineralization of nitrogen followed single first‐order kinetics and was lower for older tops (31%) than younger ones (42%) and roots mineralized least relative amounts (28%). Rate constants of nitrogen mineralization from tops of different ages were fairly similar (0.058 d−1) whereas those for roots were lower (0.035 d−1). A simple predictive measure for potential N mineralization of plant material was proposed assuming a C/N ratio of 8 in the stabilized material and a constant fraction of the non‐lignin carbon to be mineralized.
Utilization of mineral nitrogen in the subsoil by winter wheat
Authors: Kuhlmann H. , Barraclough P. B. , Weir A. H. 
Published: February 2007

AbstractUptake of nitrogen from the subsoil (30–200 cm) by winter wheat has been measured in field experiments on deep loess‐parabrown soils in northern Germany and at Rothamsted (England) for different crop rotations and manuring schemes. The results can be summarised as follows:

The mineral nitrogen content of the subsoil varies widely depending on farming practice.
The effective depth limit for N uptake by winter wheat appears to be 150 cm.
Averaged over 22 sites, 33% of the total N uptake was from the subsoil (range 9–75%); 25% was from the 30–90 cm soil layer and 8% from the 90–150 cm soil layer.
Decreasing the N supply to the topsoil increased N uptake from the subsoil.
N uptake from the subsoil is not dependent on water uptake from the subsoil; nitrate is readily transported to absorbing roots by diffusion.
When deciding on the rate of fertilizer N to apply in early spring, soil mineral N to a depth of 90 cm should be taken into account. For subsequent dressings, the soil mineral N between 90–150 cm depth needs to be considered.