bluuebunny/crossref_metadata_2025 huggingface dataset:
Veränderungen von Dreischicht‐Tonmineralen durch natives K in holozänen Lößböden Mitteldeutschlands und Niederbayerns
Authors: Niederbudde E. A.
Published: February 2007

Changes of three‐layer clay minerals by native K in holocene loess derived soils of Central Germany and Lower Bavaria.

Transformations of the clay minerals illite, vermiculite and smectite were determined in Central German (31 profiles) and Lower Bavarian loess districts (5 profiles) using 31–36 soil properties. To get significant differences between solum and sediment, the multivariate diskriminant analysis was applied.

In the Central German loess district the following properties were crucial, to receive significant separation between solum‐horizons and sediments: smectite content, several values of potassium fixation, interlattice potassium. Important were also some parameter of the K‐Ca‐exchange curve: Activity ratio \documentclass{article}\pagestyle{empty}\begin{document}$ \left({\frac{{{\rm aK}}}{{\sqrt {{\rm aCa}}}}} \right) $\end{document} of a soil solution in equilibrium with a soil (ARo), buffering capacity of the soil for K at equilibrium (BCKE), labile K(K1), exchange capacity of the exchange sites with a specific affinity for K minus labile K(ECx—K1). The differences of these values can be explained by assuming that (at pH 6–7) the beidellitic layers of smectites of the parent loess were transformed to illitic layers in the solum‐horizons.

In the Lower Bavarian loess landscape potassium fixation, total K in clay fraction (< 2 μm) and the parameters of the K‐Ca‐exchange curve indicate the same clay mineral transformation as in Central Germany. Smectite values were not introduced to the diskriminant function, because they were highly significantly correlated with potassium fixation. In this case potassium fixation has caused a better separation between the solum‐horizons and the parent loess than X‐ray data.

From these results, from total ‐K of the fraction 2–20μm (solum‐horizons smaller than sediments) and the vermiculite content fo the clay fraction, it can be concluded, that the rate of potassium release from micas and the rate of potassium fixation by beidellitic sheets during the Holocene period were nearly equal.
Chrom und Quecksilber in einem seit 80 Jahren mit städtischem Abwasser berieselten Boden
Authors: El‐Bassam N. , Poelstra P. , Frissel M. J.
Published: February 2007

Chromium and mercury in a soil after 80 years of treatment with urban sewage water.

A soil (tab. 1) which is since 80 years under irrigation with sewage water contains 112 ppm Cr and 1.5 ppm Hg (Fig. 1). The sewage water presently contains 0.07 ppm chromium and 0.002 ppm mercury. In order to study the migration and leaching of chromium in the soil experiments were carried out with 51Cr as CrO42‐ under aerobic and 51Cr als Cr3+ under anaerobic conditions in undisturbed soil columns. In all cases chromium was adsorbed in the layer 0–5 cm (Fig. 2 and 3). Similar experiments with 203Hg as HgCl2 (Fig. 4) showed that mercury ist adsorbed near the surface. These experiments confirmed our results of ground water analyses, neither chromium nor mercury contaminated the ground water.
Die Aufnahme und Verlagerung des Phosphorsäurediäthylesters im Vergleich zum Orthophosphat
Authors: Allam N.
Published: February 2007

Uptake and Translocation of Diethyl Phosphoric acid Ester in Comparison to the Orthophosphate..

The uptake of the diethyl phosphoric acid ester (DEP) through intact adventive roots of maize plants and its further translocation to the shoots was studied over a wide range of concentrations (0.001–50.0 mM P/L) in comparison to the orthophosphate (MP). The effect of the relative humidity (r.h.) and the metabolic inhibitor Na N3 on both processes, uptake and translocation, was also investigated.

At low concentrations the plants tended to retain a greater part of the MP intaked in the absorbing roots. Depression of the transpiration streaming influenced relatively the phosphate translocation to the shoots. The higher the MP‐outside‐concentration was, the greater the effect of the transpiration streaming was on its translocation. Treatment with 10‐4 MNaN3 inhibited MP‐accumulation but not its translocation from the treated roots.

The results showed that passive processes are mainly responsible for the DEP‐uptake and translocation by the maize plants. Both processes were dependent to a great extent on the transpiration streaming.

The r.h. affected the translocation patterns of both DEP and MP dissimilarly at low concentration, though, they come close to each other when their outside concentrations were increased.

The results are discussed on the basis of the symplasm theory (2) and the dual mechanisms of ion uptake (28).
Halmverkürzungen bei Winter‐ und Sommerroggen durch Ethrel (2‐Chloräthylphosphonsäure)
Authors: Raafat A. , Kühn H.
Published: February 2007

Reduction of stalk length in winter and summer rye by Ethrel (2‐chloroethylphosphonic acid).

In pot experiments with winter and summer rye Ethrel (2‐chloroethylphosphonic acid) considerably reduced stalk length so that a favourable effect on lodging can be expected. The shortening effect strongly depends on the time of application. Grain yield is scarcely affected. The experiments give indication for the optimal concentration and the amount of active substance required.
Erosionsbedingte Stoffverteilung in zwei hopfengenutzten Kleinlandschaften der Hallertau (Bayern)
Authors: Schwertmann U. , Huith M.
Published: February 2007

Spatial distribution of some elements on two microlandscapes in Bavaria under hop growing as influenced by soil erosion..

In order to gain information about lateral soil movement on loess covered slopes the spatial distribution of Cu (applied as fungicide), total P and Corg. were measured in two microlandscapes under continuous hop growing. The depth functions of these elements clearly indicate a strong lateral mass movement before but also mainly after hop growing commenced (25 years ago). Using a geometric series the soil loss at various positions was estimated to range between 1 and 20 mm per year which is in the same range as the depth of colluvium in the depression as seen from the depth functions.
The exchangeable ion effect on the thermal decomposition of Wyoming Bentonite
Authors: Tahoun Salah A. , El‐Sayed Karimat M.
Published: February 2007

Der Effekt des austauschbaren Ions auf die thermische Zersetzung von Wyoming‐Bentonit..

Homoionische Li−, Ca−, Al− und Fe‐Montmorillonite wurden 6h auf Temperaturen zwischen 600 und 1200°C erhitzt. Dabei geht austauschbares Li in vakante Oktaederpositionen des Tonminerals und substituiert anschließend inhomogen Al. Deshalb wurde hier die deutliche Abnahme der Kristallgröße des Li‐Montmorillonits im Gegensatz zum beobachteten Erhitzungseffekt bei den anderen Systemen zur Erklärung herangezogen. Abgesehen vom Cristobalit, der als Hochtemperaturphase in allen Systemen auftrat, entstanden in den unterschiedlichen Systemen verschiedene Phasen. Austauschbares Li, Ca und Fe bildeten Spodumen, Anorthit und Hämatit, wogegen austauschbares Al in die Tonmatrix aufgenommen wurde.
Manganese and Copper Deficiency of Plants as a Characteristic Defect of Lowmoor Peat Soils
Authors: Szalay A. , Sámsoni Z. , Szilágyi M.
Published: February 2007

Mangan‐ und Kupfermangel der Pflanzen als ein charakteristischer Defekt der Torfböden.

In der vorliegenden Arbeit werden die wichtigsten Ergebnisse eines ausgedehnten Untersuchungsprogrammes über einige Eigenschaften von Torfböden dargestellt. Diese Untersuchungen wurden durch frühere Laboruntersuchungen mit Radioisotopen eingeleitet, in denen gezeigt werden konnte, daß unlösliche Torf‐Huminsäuren einen hohen Retentionsfaktor (R.F.) für kationische Mikronährstoffe haben.

Jetzt vorgelegte umfangreiche Analysendaten von Pflanzen von Torfstandorten beweisen, daß Pflanzen von Torfböden im Vergleich mit guten Mineralböden in bezug auf Mangan und auch auf Kupfer unternährt sind. Eine Düngung der Torfböden mit Mn2+‐ und Cu2+‐Salzen konnte diese Mangelerscheinung nicht beseitigen, da die starke Kationensorption an unlöslichen Huminsäuren die Aufnehmbarkeit verhindert. Eine Blattbesprühung mit Mn2+ und Cu2+ versorgte jedoch die Pflanzen ausreichend und beseitigte die Mangelerscheinungen.

Die Bedeutung dieser Beobachtungen für die Nutzbarmachung der riesigen Torfflächen in der nördlichen Hemisphäre wird betont.
Zum Einfluß landwirtschaftlicher und forstlicher Nutzung auf die Wasser‐ und Luftverhältnisse typischer Böden aus Löß Nordwürttembergs
Authors: Blume H. ‐P. , Zimmermann U.
Published: February 2007

Soil water and air regime under forest and agriculture in loess soils in South‐West Germany.

Investigations on loess soils of South‐West Germany showed distinct differences in the water and air regime under forest and agriculture. The water content was higher and the air content lower under cultivation and grassland as compared to forest. These results are caused by less transpiration of agriculture crops on cultivated plots and also by a higher bulk density of this soil due to tillage.
Sodium‐calcium and magnesium exchange equilibria in soils
Authors: Aboulroos Samir A.
Published: February 2007

Natrium ‐ (Calcium + Magnesium) ‐ Austauschgleichgewichte in Böden.

Beckett's approach has been used to describe the Na‐(Ca + Mg) exchange isotherm in twenty soil samples that differed in texture and salinity. The data obtained from the isotherms were compared with the values of exchangeable sodium obtained by ammonium acetate and the concentration ratios (Na/ °Ca+Mg) calculated from the saturation paste extract.

The Na‐Q/I relation was always linear for each of the studied soils with no curvature at the lower values of concentration ratio. Values of ‐ Δ Na0 obtained from the isotherms were highly correlated with exchangeable Na (r2 + 0.89). The equilibrium concentration ratios of the isotherms were similar to those obtained from the saturated paste extract in the non‐saline soils, and were much lower in the case of the salt affected soils. The slope of the Na‐Q/I relation appeared to be a soil characteristic not affected by either Na depletion from the soil or Na addition up to 5 me./100 g. soil. The PBCNa values were highly correlated with the C.E.C. values of the soil (r2 + 0.97).
Einfluß der Saugspannung auf den Wasserentzug durch die Wurzeln einer Grasvegetation
Authors: Flühler H. , Richard F. , Thalmann K. , Borer F.
Published: February 2007

Relations between root water uptake and soil moisture tension.

The root water uptake Q expressed as sink term of the continuity equation was computed using exclusivly field measured data of a post‐irrigation water transport study. The experiment was carried out in an undisturbed Loess soil monolith.

The soil moisture redistribution influenced by the evapotranspiration of the grass cover and the soil moisture characteristics were measured independently using the identical experimental layout.

The data show a clear relationship between the root water uptake Q and the soil moisture tension S. Within the tension range of approx. 0–100 mbar the uptake Q decreases drastically with water desaturation. Within the upper part of the rooting zone this decrease is more pronounced and starts at a lower tension.
Evaluation of various parameters for available phosphorus in alluvial and calcareous soils of Eypt
Authors: Metwally A. I. , Hamdy H. , El‐Baz S.
Published: February 2007

Bewertung verschiedener Parameter zur Feststellung des pflanzenverfügbaren Phosphats in alluvialen und kalkhaltigen Böden Ägyptens.

Mit Hilfe von 32P wurde in Alluvial‐ und Kalkböden die Bewertung unterschiedlicher Parameter (Intensität, Kapazität und Kombination beider mit einem kinetischen Faktor) zur Kennzeichnung des pflanzenverfügbaren P vorgenommen.

Zwischen dem P‐Gehalt in Weidelgras und der Intensität (P im 0,01 M CaCl2‐Extrakt, Verh. Boden/Lösungsmittel + 1/20, Schüttelzeit + 18 h) ergaben sich keine gesicherten Beziehungen. Die durch Isotopen‐Austausch und im Bicarbonat‐Extrakt gemessene Kapazität war dagegen sehr hoch korreliert mit der tatsächlichen P‐Aufnahme von Weidelgras in beiden Bodengruppen. Der E‐Wert (gemessen nach 14 d) ergab bei den Kapazitätsparametern die besten Beziehungen, gefolgt vom L‐Wert und dem E‐Wert nach 18 h, während die Bicarbonat‐Extraktion die schlechteste Korrelation lieferte.

Am besten allerdings war die P‐Aufnahme durch die Pflanzen korreliert mit der P‐Menge, die durch Anionenaustauscher aus der Bodenlösung innerhalb von 16 h entfernt wurde. Dies stützt die Hypothese, wonach neben Intensität und Kapazität die Wiederauffüllungsrate von P in der Bodenlösung hinsichtlich seiner Pflanzenverfügbarkeit starke Bedeutung hat.
Effect of phosphate dissolving bacteria and phosphate fertilization on the P‐uptake by pea plants cultivated in a calcareous soil
Authors: Kabesh M. O. , Saber M. S. M. , Yousry M.
Published: February 2007

Einfluß von phosphatlösenden Bakterien und Phosphatdüngung auf die Phosphataufnahme von Erbsenpflanzen auf Kalkböden.

In Gefäßversuchen im Gewächshaus wurde in Gegenwart und Abwesenheit von phosphatlösenden Bakterien (PDB) der Einfluß von Superphosphat und Thomasphosphat auf die Phosphataufnahme von Erbsenpflanzen aus einem Kalkboden untersucht. Durch Beimpfung mit PDB und/oder durch die Phosphatdüngung wurde die Phosphataufnahme der Erbsenpflanzen erhöht. Alleinige Anwendung von PDB, Superphosphat oder Thomasphosphat erhöhte die Phosphataufnahme um 14,3, 19,1 bzw. 6,7% gegenüber den ungedüngten Kontrollen. Durch Kombination von PDB mit Superphosphat bzw. Thomasphosphat erhöhte sich die Phosphataufnahme um 44,1% bzw. 30% gegenüber der Kontrolle.
Studies on Microbial Fertilizers. III. Effect of phosphate and silicate dissolving bacteria on the uptake of phosphorus and potassium from calcareous soils by sorghum helepensis
Authors: Saber M. S. M. , El‐Sherif A. F. , Osman A. Z.
Published: February 2007

Einfluß von phosphat‐ und silikat‐auflösenden Bakterien auf die P‐ und K‐Aufnahme von Sorghum helepensis aus kalkhaltigen Böden..

Der Einfluß einer kombinierten Impfung mit phosphat‐ und silikatauflösenden Bakterien (Bacillus megaterium var. phosphaticum bzw. Bacillus sp) auf die P‐ und K‐Aufnahme von Sorghum helepensis wurde in Topfversuchen ermittelt. Als Substrat dienten kalkhaltige Böden mit 25,54 bzw. 96% CaCO3.

Während kombinierte Impfung die K‐Aufnahme nicht beeinflussen konnte, wurde die P‐Aufnahme in allen Versuchsvarianten deutlich erhöht. Der P‐Anteil im Sudangras aus markiertem Superphosphat nahm in den beimpften Varianten deutlich ab.
Dissolution and Plant uptake of P from Ca phosphates with varying particle size in two soils. II. Plant uptake by alfalfa and rye grass
Authors: Metwally A. I. , El‐Baz S.
Published: February 2007

P uptake by rye grass and alfalfa from smaller particle size of DCPD (≦ .18 mm) was larger than that from larger granules (0.4–0.5, 1.0–1.25, and 1.5–1.75 mm). Differences, however, became smaller with increasing time of contact. However powdered MCP was superior to all DCPD particles size fraction in an alluvial clay and a calcareous sandy clay loam indicating that under such alkaline reaction, the rate of dissolution is more limiting than the rate of immobilization. Results also indicate that the phosphate mobility in the highly calcareous was much lower than in the clay soil due to high pH and carbonate content.
Einfluß von Reifedauer, Temperatur und Sauerstoffversorgung auf die Bildung von ungesättigten Fettsäuren und Tocopherolen in Sonnenblumenfrüchten
Authors: Dompert W. U. , Beringer H.
Published: February 2007

Influence of ripening, temperature and oxygen supply on the synthesis of unsaturated fatty acids and tocopherols in sunflower seeds

The ratio of vitamin E (tocopherol)/polyunsaturated fatty acids (T/PUFA) is of importance in the storage and consumption of oils and diets. In previous experiments low temperature and cool climate during seed development of sunflowers were found to decrease the T/PUFA in the seeds (Beringer and Saxena, 1968; Dompert et al., 1975). This may be due to a) a prolonged „filling period”︁ at low temperatures and/or b) a direct effect of temperature on the synthesis of oil and tocopherol in the seeds.

Harvesting sunflower seeds, grown in a climate‐chamber at 22°C, at 1, 8, 15, 25, 31 and 40 days after pollination revealed an intensive lipid synthesis in the seeds between 8 and 31 days after pollination, thereafter a small decline of total lipids occured. Total tocopherols, with α‐tocopherol dominating, were synthesized nearly parallel to total lipids. Accordingly a ratio of 1 mg tocopherol/g seed‐oil and approximately 3–4 mg tocopherol/g linoleic acid respectively from 8 days after pollination till maturity was found.

Increased growth temperatures (day and night same) from 10 to 22 up to 35°C from flowering till maturity caused a decrease in oil content and linoleic acid percentages. An attempt to compensate the stimulating effect of low temperatures on fatty acid desaturases by flushing sunflower‐heads with gas mixtures of 21% O2 (10°C plants), of 28% O2 (22°C plants) and 38% O2 (35°C plants) according to Harris and James (1969) resulted in only slight increases of linoleic acid, which were with 23,5% at 35°C and 40,7% at 22°C still much lower than at 10°C, where linoleic acid was linoleic acid was 62,8% of total fatty acids. Under natural conditions a direct influence of growth temperature seems therefore more likely in determining the fatty acid composition than temperature dependant rates of O2‐diffusion into the seed tissue. Unlike fatty acid synthesis the synthesis of tocopherols was not significantly influenced by the growth temperature. But due to decreasing oil content and linoleic acid percentages at higher temperatures the α‐Tocopherol/g oil as well as the α‐tocopherol/g linoleic acid was continuously raised. The latter increased from 0,9 at 10°C up to 7,8 at 35°C i. e., the ratio of 1 I. U. vitamin E/g PUFA required in animal and human nutrition was achieved at all temperatures tested.

The parallelism of oil‐ and tocopherol‐content in developing sunflower seeds on the one side and the large, temperature dependant variability of the T/PUFA‐ratio on the other side suggest, that no „stoichiometric”︁ relation exists between the synthesis of tocopherols and fatty acids in sunflower seeds. Fatty acid desaturases in oil seeds are membrane‐bound enzymes and tocopherol might be involved as an antioxydative stabilizer of the membrane as it is known from animal tissues (McCay et al., 1971).
Berechnung des labilen Phosphats aus Phosphat‐Pufferkurven (Q/I‐Kurven)
Authors: Schwertmann U. , Fischer W. R. , Knittel H.
Published: February 2007

Calculation of labile phosphate from phosphate buffer curves

A procedure to calculate labile P from phosphate buffer curves (Q/I curves) is presented. It treats the buffer curves as Langmuir adsorption isotherms and calculates the labile P by extrapolation to zero. In a long term P fertilizer trial the labile P calculated in this way was nearly equal to the increase in plant available P as extracted by calcium lactate. From a heavily fertilized vineyard soil, on the other hand, more P was extracted by 3 · 10−3 M CaCl2 during the first extractions than calculated from the buffer curves whereas on further extractions the two quantities approached each other.
Der Umsatz von Pflanzenwurzeln im Laufe der Vegetationsperiode und dessen Beitrag zur „Bodenatmung”︁
Authors: Sauerbeck D. , Johnen B.
Published: February 2007

The Turnover of Plant Roots during the Growth Period and its Influence on “Soll Respiration”

Mustard and wheat plants were grown under 14CO2, their roots being tightly separated from the shoot sphere. Root formation, root respiration, and root decomposition could thus be followed during the plant development by radiometric methods. The total quantity of organic root matter in soil at harvest time turned out to be 20–50% larger than the amount of root residues as determined by ordinary washing procedures.

Depending on the plant and duration of the experiment, an additional amount of up to three times more than this remaining root carbon was already mineralized during the vegetation period. Only one fifth of this 14CO2‐production could be attributed to the respiration of living root tissue, all the remainder seemed to be due to the microbial decomposition of dead roots, root residues and root excretions. Root respiration and root decomposition together produced almost four fifths of the total evolving CO2‐quantity, whilst the contribution from soil organic matter breakdown did not exceed one fourth of it.

According to these data, the total rhizo‐deposition amounts to 3–4 times as much organic substance than what can be found as root residues at harvest time. This rich supply of readily decomposable organic matter leads to a most intensive turnover in the rhizosphere, which should be of considerable influence on the dynamic processes in soil.
Bestimmung von hydraulischen Parametern für die Wasserhaushaltsuntersuchungen im natürlich gelagerten Boden. Ein Vergleich von Feld‐ und Laboratoriumsmethoden
Authors: Flühler H. , Germann P. , Richard F. , Leuenberger J.
Published: February 2007

Determination of hydraulic parameters to estimate water movement and water storage in undisturbed soil. A comparison of field and laboratory methods.

The soil moisture characteristics and the unsaturated conductivity were measured under field and laboratory conditions. In an undisturbed soil monolith in continous connection with the underlying loess‐soil‐layer 60 tensiometer and a neutronprobe‐accestube were used respectively to determine the matric potential and water content changes during a transient drainage experiment. Within the matric potential range of 0 to approximately −50 to −100 mbar the soil moisture characteristics determined in the laboratory and in the field are substantially different. When the matric potential is more negative than −100 mbar the slope of these curves and hence the specific moisture capacities are relatively well comparable.

The field‐measured conductivity functions differ considerably from those values which were either measured under lab‐conditions or computed from the soil moisture characteristics data. The conductivities are expressed as a function of the matric potential which is possibly the major reason for these remarkable differences. However, the changes in water content in this dense silty clay loam are too small to express the unsaturated conductivity as a function of the absolute water content. The most serious problems in extrapolating the results of the less time consuming laborcalculation methods to field conditions arise in that range of matric potentials where water movement is significant.
Effect of straw and ammonium nitrate on growth, nitrogen fixation and yield of soybeans
Authors: Shivashankar K. , Vlassal K. , Livens J.
Published: February 2007

Einfluß von Stroh und Ammoniumnitrat auf Wachstum, Stickstoffixierung und Ertrag von Sojabohnen

In einem Gefäßversuch mit sandigem Lehmboden wurde dem Einfluß von Stroh und Ammoniumnitrat auf Wachstum, symbiotische N2‐Bindung und Ertrag von Glycine max (L) Merr. cult. Caloria nachgegangen.

Die Versuchsglieder waren: Kontrolle, 9 und 18 g Stroh/Gefäß und 0,9 und 1,8 g N/Gefäß in Form von NH4NO3. Die Verabreichung von Stroh bei der Aussaat erhöhte die N2‐Bindung gegenüber der Kontrolle. Weiter erhöhte die Strohdüngung, besonders bei hoher Gabe, Blattzahl, Blattgewicht, Trockenmasse und den Samenertrag. Düngung mit 0,9 g N/Gefäß ergab einen Mehrertrag von 86%.
Evaporation, drainage and unsaturated hydraulic conductivity of tilled and untilled fallow soil
Authors: Ehlers W. , van der Ploeg R. R.
Published: February 2007

Evaporation, Tiefensickerung und ungesättigte hydraulische Leitfähigkeit auf bearbeiteter und unbearbeiteter Brache

Auf einer brach gehaltenen Löß‐Parabraunerde wurden die Evaporations‐ und Versickerungsraten sowie die ungesättigte hydraulische Leitfähigkeit bestimmt. Die Versuchsfläche war in eine konventionell bearbeitete und in eine über vier Jahre nicht mehr bearbeitete Vergleichsparzelle aufgeteilt. Während der Versuchsdauer wurde der Boden von einer Mulchdecke freigehalten. Tensiometer wurden in 10, 20, 30, 40, 60, 80, 100, 120, 150 und 180 cm Tiefe installiert und täglich abgelesen. Zweimal wöchentlich wurden Bodenproben zur Feuchtebestimmung bis 2m Tiefe entnommen. Sie wurden in 10 cm lange Abschnitte aufgeteilt. Während längerer Zeiten ohne Niederschlag entwickelte sich im Boden eine Wasserscheide, die sich langsam im Bodenprofil abwärts bewegte. Mit Hilfe dieser Wasserscheide konnten die Evaporations‐ und Versickerungsrate sowie die ungesättigte hydraulische Leitfähigkeit berechnet werden. Die Raten für Evaporation und Tiefensickerung waren im Frühjahr am höchsten. Zum Herbst hin nahmen sie ab. Die über die gesamten niederschlagsfreien Perioden ermittelte Durchschnittsrate für Evaporation und Versickerung war auf beiden Bearbeitungsvarianten gleich hoch. Die Werte für die ungesättigte hydraulische Leitfähigkeit streuen bei gleicher Wasserspannung erheblich. Wahrscheinlich ist diese Streuung auf Hysterese und örtliche Bodenunterschiede zurückzuführen. In den Schichten von 20–30 und 30–40 cm des unbearbeiteten Bodens liegen die Leitfähigkeitswerte im Bereich geringer Wasserspannungen (< 100 cm H2O) höher als im bearbeiteten Boden. Das Ergebnis scheint darauf hinzudeuten, daß der unbearbeitete Boden im niedrigen Wasserspannungsbereich über ein kontinuierliches System von Grobporen verfügt und daß dieses Grobporen‐System im bearbeiteten Boden regelmäßig zerstört wird.
Einfluß von N‐Lignin auf Wachstum und N‐Stoffwechsel von Weizen‐Zellsuspensionskulturen
Authors: Golvano P. , Harms H. , Söchtig H.
Published: February 2007

The effects of N‐Lignin on growth and N‐metabolism in wheat cells in suspension cultures

N‐Lignin is an organic N‐fertilizer which is synthesized from waste liquors of the pulp industry by oxydative ammonisation. Nearly 40% of its N‐content is available as ammonium, the rest is linked in organic compounds.

Water‐soluble fractions of N‐Lignin were added to the nutrient solutions of wheat cells in suspension cultures in order to study the effects on growth and N‐metabolism. The experiments show that N‐Lignin is a suitable nitrogen source for growing wheat cells. The best growth was achieved when 50% of the total nitrogen content of the medium were added as N‐Lignin nitrogen. This mixture of N‐Lignin and nitrate was even superior to the standard B‐5‐medium with respect to the final dry weight. However, higher concentrations of N‐Lignin inhibited cell growth. The effect of N‐Lignin on cell growth is not only influenced by ammonia. If wheat cells were grown on media with ammonium‐N as the sole nitrogen source acids of the citrate cycle had to be added to support growth. This was not necessary with N‐Lignin. N‐Lignin therefore seems to effect the energy metabolism.

High amounts of ammonium‐N or the reduced N‐fractions of N‐Lignin respectively resulted in an increase of certain amino acids and especially of the two amides glutamine and asparagine.

Furthermore root formation was observed with cells grown in media containing N‐Lignin or ammonium‐N. The root formation seemed to be correlated with added amounts of reduced nitrogen. Root formation was not observed with cell cultures incubated with N‐Lignin solutions which were made free of ammonium‐ions with a cation exchanger (Amberlite IR‐120) loadad with potassium. This indicates that the differentiation of roots in the normally embryonic cells is due to the ammonium‐N content of N‐Lignin.

A possible correlation between the content of glutamine and asparagine and the formation of roots is discussed.
Sensitivity of a simulation model on nitrate out flow from soil profile to parameters representing various climatic and agrotechnical conditions
Authors: Hagin J. , Amberger A. , Segall E. , Kruh G.
Published: February 2007

Empfindlichkeit eines Simulationsmodelles über die Nitratbewegung im Bodenprofil entsprechend verschiedenen klimatischen und ackerbaulichen Bedingungen

Ein Simulationsmodell über den Einfluß von ackerbaulichen Maßnahmen auf die Nitratauswaschung wurde dargestellt für einen schweren Lehm und einen schluffigen Lehmboden. In einem simulierten System reduzierte eine zunehmende Häufigkeit der Beregnung bei konstanter Gesamtwassermenge die Menge an Perkolationswasser sowie die Verluste durch Nitratauswaschung und Denitrifikation. Eine Verdoppelung der Gesamtwassermenge erhöhte die Menge an Perkolationswasser sowie die Denitrifikation beträchtlich, die Stickstoffauswaschung aber um das 10–20fache. Die angewandte Stickstofform (organisch oder anorganisch) sowie die Applikationsrate waren von geringer Bedeutung.

Für einen der Böden konnte gezeigt werden, daß mehr Nitrat ausgewaschen wurde ohne mineralische N‐Düngung und Pflanzenbesatz als wenn das Wasser durch einen normalen Pflanzenbestand transpiriert und Nitrat aufgenommen wurde.
Schwermetallgehalte im Kultursubstrat und Erntegut des Champignons, Agaricus bisporus (Lange) Singer, beim Einsatz von Müllklärschlammkompost
Authors: Domsch K. H. , Grabbe K. , Fleckenstein J.
Published: February 2007

Heavy metal contents in the culture substrate and in the mushroom, Agaricus bisporus, grown in composts mixed with municipal waste and sewage

The addition of increasing quantities of municipal waste compost to conventional horse manure compost resulted in a proportional increase in the heavy metal content of the mixture. The increases ranged between 250% (zinc) and 900% (mercury).

Ninety‐four to ninety‐nine percent of the heavy metals in municipal waste compost are bound in compounds from which they can not be extracted using CaCl2 solution. The amounts extractable from horse manure compost with CaCl22 solution are from 1.5 (zinc)‐ to 33 (mercury)‐times higher.

The influences of the increasing quantities of heavy metals in municipal waste — horse manure composts are demonstrable in the content of these metals in harvested mushroom. This, in turn, corresponds to the availability of the metals. The relative enrichment is greatest with mercury, and least with cadmium. The quantities found in mushrooms, with the exception of mercury, fall within the normal range detected in vegetable crops.
Beeinflussung der Assimilatspeicherungsprozesse in der Sommergerstenähre durch Kinetinbehandlungen
Authors: Aufhammer W. , Solansky S.
Published: February 2007

Effect of kinetin treatments on the accumulation of assimilates in the ears of spring barley

Using individual plants of spring barley, cultivar Emir, during the grain‐filling period the attempt was made to increase the production of assimilates and their storage in the ear by exactly timed and located application of kinetin solution. The production of assimilates in the flag leaf and their distribution were controlled by 14CO2‐labelling.

The experiments showed the following results: 1. Treatments of the whole ear or the growing grain respectively with kinetin solution increased the ability of the ear to attract assimilates and increased the storage of assimilates, formed in the flag leaf. Moreover an increase in the assimilation rate of the flag leaf could be observed. 2. Treatments of the flag leaf blade with kinetin solution induced retention‐effects of assimilates in this organ. After a temporary depression a distinct and continuous increase of the assimilation rate became apparent. 3. After treatments of the ear (resp. the grains) as well as after treatments of the flag leaf increasing yields were achieved as the result of increasing thousand‐kernel‐weights.

The results are discussed under physiological and yielding aspects.
Eine Einrichtung zur Beregnung von Bodensäulen
Authors: Beese F. , Heuer C. , Rodewald W.
Published: February 2007

A device for the irrigation of soil columns

An irrigation device was designed for maintaining a constant water flow in soil columns over a long period of time. The apparatus consists of three construction elements: A balance for the dosage of the water, a sprinkler to distribute the water on the soil surface and an electronic time control to adjust different time steps. The wide range of possible rain intensities is shown. The mean variation of the water pulses and their distribution over the surface are discussed. The apparatus exhibits good results in long duration experiments.
Speicherungsprozesse — die Rolle der Phytohormone
Authors: Dörffling K.
Published: February 2007

Storage processes — the role of plant hormones

The role of plant hormones in the regulation of induction and development of fruits and vegetative storage organs and in the storage process is critically reviewed. Evidence is presented that growth and development of storage organs is regulated by a complex interaction of all known plant hormones. By changing the sink‐capacity the hormones influence the intensity and direction of the assimilate flow. Beyond this more indirect effect on the flow of assimilates few observations indicate a direct effect of hormones on the transport system.
Rolle der Cytokinine bei Blüten‐ und Früchteentwicklung
Authors: Bruinsma J.
Published: February 2007

Role of cytokinins in flower and fruit development

After a survey of the literature on the role of cytokinins in flower development, it is discussed whether the accumulation of cytokinins in developing seeds is a cause or the result of the sink activity of these seeds. Although most data indicate accumulation of cytokinins derived from elsewhere, possible local biosynthesis of cytokinins within developing seeds should be further investigated, particularly in experiments with isolated ovaries and ovules cultured in vitro.
Wachstum und Reife der Weinbeere
Authors: Alleweldt G.
Published: February 2007

Growth and ripening of berry grapes

Berry enlargement shows a characteristical double‐sigmoid curve. It can be shown that there was an increase up to a maximum in the amount of endogenous auxin and cytokinin during the period of the first berry growth and a sudden decrease after having attained a short stop of berry growth. Accumulation of sugars in the fruits begins during period I1 of growth enlargement, at the same time the content of ABA increases. Possible relations between phytohormonal regulation of berry growth and the role of plant hormones as to translocation of carbohydrates from the leaves into the berries are discussed.
Trockensubstanzproduktion und Assimilateinlagerung in das Getreidekorn
Authors: Stoy Volkmar
Published: February 2007

Dry matter production and accumulation of assimilates in cereal grain

The grain yield of a cereal crop is the product of the morphological yield components grain number and grain size and these are in turn the result of the interaction of three main physiological factors, i.e. 1) magnitude of assimilate production (source), 2) storage capacity of
Leaching of Added Selenium in Soils Low in Native Selenium
Authors: Gissel‐Nielsen G. , Hamdy A. A.
Published: February 2007

Auswaschung von zugegebenem Selen aus Böden mit niedrigem Gehalt an nativem Selen

In einem Versuch mit Bodensäulen wurde die Einwirkung von organischer Substanz und Kalk auf die Auswaschung und die Verteilung von Selenit‐Zusatz untersucht. Den wassergesättigten Bodenproben in Säulen mit einem Durchmesser von 4,25 cm und einer Länge von 16–20 cm wurde mit 75Se markiertes Na2SeO3 zugesetzt. Die Auswaschung wurde unmittelbar darauf begonnen und im Verlauf 1 Woche 11 Wasser zugesetzt. Der überwiegende Teil des Selenits bewegte sich nicht durch den Boden; nur einige % konnten im Sickerwasser nachgewiesen werden. Die Auswaschung war im sandigen Boden am größten. Sie wurde durch Zusatz von Kalk erhöht, durch Zusatz von organischer Substanz jedoch herabgesetzt. Die Auswaschung erfolgte vorwiegend während der ersten paar Tage. In anderen Experimenten konnte gezeigt werden, daß die Fixierung von Selenit im Boden einige Tage braucht, um den Gleichgewichtszustand zu erreichen. Es wird daher gefolgert, daß in den meisten Fällen eine Auswaschung von Selenit nach Zugabe zu Mineralböden unter den dänischen Feldbedingungen im Kurzzeitzyklus des Selens in der Umwelt unerheblich ist.
Wirkung von Ancymidol auf Längenwachstum und Chlorophyllgehalt von Helianthus annuus L. in Wasserkultur
Authors: Höfner W.
Published: February 2007

Effect of Ancymidol on growth and chlorophyll content of Helianthus annuus L. in water culture experiments

Height of young sunflower plants in water culture was shortened up to 30 % by 0,75 ppm ancymidol in the nutrient solution.

The chlorophyll concentration of the aerial plant parts increased from 15 to 30 %under the influence of 0,75 ppm ancymidol, the amount of chlorphyll per plant however was not changed compared with the control.

The reduced height of the ancymidol plants was accompanied by a reduced fresh weight, in some cases also by a lowered dry weight of plants. Dry weight of the roots of ancymidol plants was not changed.
Fotometrische Messung der PEP‐Carboxylase‐Aktivität in Maisblättern unter Berücksichtigung des Entwicklungszustandes der Pflanze
Authors: Möller G. , Stamp P. , Geisler G.
Published: February 2007

Photometric estimation of the activity of phosphoenolpyruvate carboxylase in maize leaves as depending on plant development

In order to measure photometrically the activity of Phosphoenolpyruvate carboxylase in homogenates of maize leaves, a method for larger test series was developed. When optimal conditions for the mixture, the pH‐value and the temperature of the test mixture had been developed, reliable values were measured.

The activities of Phosphoenolpyruvate carboxylase are dependant on the age of maize leaves. The activities increased during the first ten days of leaf development. The following twenty days were marked by a relatively small reduction of the activity. Thereafter a steady decline of the activity took place.
Extraktion freier Aminosäuren aus Pilzsporen (Phycomyces blakesleeanus)
Authors: Furch B. , Steinberg Ch.
Published: February 2007

Extraction of free amino acids from fungal spores (Phycornyces blakesleeanus)

Because extraction conditions are crucial for the reliability of biochemical analysis of fungal spore materia1, comparative investigations on methods were conducted, using the amount of free amino acids as a parameter of exhaustive extraction. It was found that optimal conditions are: Extraction in a Soxhlet apparatus with methanol as extracting medium (for 8 hours under reduced pressure and 40°C boiling temperature) or treatment with ice‐cold perchloric acid (10 % for 30 minutes) or trichloroacetic acid (10 % for 30 minutes). A pretreatment of the material by desintegration was not necessary. Extraction with hot water (70 or l00T) or with ethanol, propanol, butanol, 3,3 %perchloric or trichloroacetic acid proved to be inappropriate.

All of the common amino acids were detected in the extracts except proline and phenylalanine. A few amino acids make up the majority of the pool (glutamic acid, glutamine, aspartic acid, asparagine, alanine and y‐butyric acid). These amino acids comprised about 80% of the total intracellular pool (ca. 12000 moles/l00mg spores) and account for nearly 2% of the spore dry weight. Sacrosine, probably being present in considerable amounts, could not be determined quantitatively.
A contribution to the study of ZnCl+ adsorption by soils
Authors: Papanicolaou E. P. , Nobeli Catherine
Published: February 2007

Beitrag zum Studium der ZnCl+ ‐Adsorption durch Böden

In 3 carbonatfreien und 3 kalkhaltigen Bodenproben aus verschiedenen Bezirken Griechenlands und in einem Yolo‐Lehm aus Davis, Kalifornien wurde die Menge des adsorbierten Zinks bestimmt durch isotopische Verdünnung von mit 65Zn‐markiertem ZnCl2 und außerdem aus der Differenz zwischen Gesamt‐Zink und Gesamt‐Chlorid. Zusätzlich wurde die Menge des adsorbierten Chlorids durch isotopische Verdünnung von mit 36Cl‐markiertem ZnCl2 bestimmt. Man kann aus den Ergebnissen folgern, daß die Menge des Komplex‐Ions ZnCl+ nicht bedeutsam ist. Die Ergebnisse zeigen, daß die beobachteten Diskrepanzen im Fall der kalkhaltigen Böden wahrscheinlich durch die Ausfällung oder Immobilisation des Zinks oder durch die Löslichkeit der Zn‐Fällungsprodukte in der Extraktionslösung zu erklären sind.
Effects of fungicides on the microbiology and biochemistry of soils — a review
Authors: Wainwright M.
Published: February 2007

Eingriffe von Fungiziden in die Mikrobiologie und Biochemie von Böden — eine Übersicht

Bereits im Jahre 1970 war das Fungizid Captan das in der Anwendung Dritthäufigste Pestizid in den U.S.A. Damit soll die zunehmende Bedeutung der Fungizide in der Pedosphäre betont werden und eine zusammenfassende Abwägung der verschiedenen Wirkungsweisen dieser Pestizide (a) auf die Besiedlungsdichte an Bodenpilzen, (b) auf die einzelnen Pilzarten in Böden, (c) auf die bakterielle Gesamtflora (heterotrophe und autotrophe Organismen) und (d) auf die Actinomyceten rechtfertigen.

Die Applikation von Fungiziden bewirkt häufig eine vorübergehende Gleichgewichtsstörung der Mikroflora. Wohl am stärksten reagieren die Pilze, einmal in einer starken Abnahme ihrer Gesamtdichte, zum anderen in einer Vermehrung bestimmter Gattungen (oft Trichoderma und Penicillium spp.). Unter den Bakterien sind es insbesondere die autotrophen Nitrifikanten (Nitrosomonas spp. und Nitrobacter spp.), welche empfindlich auf die Anwendung von Fungiziden reagieren. Die Hemmung der Nitrifikation macht sich vielfach in einer NH4‐Akkumulation bemerkbar. Gelegentlich auch können geringe Applikationsraten die Nitrifikation fördern. Aber auch die phosphatauflösenden Bakterien scheinen positiv beeinflußt zu werden, was sich in einer Zunahme der CaCl2‐löslichen Bodenphosphate niederschlug. Aber auch andere Kationen wie K und Mg können nach einer Fungizidbehandlung (Benomyl) besser pflanzenverfügbar werden.

Fungizide können darüberhinaus die Zersetzungsrate von Streustoffen signifikant beeinflussen, einmal durch Verminderung der zellulolytischen Pilzflora, zum anderen durch Schwächung der Enzymaktivitäten beim Abbau von Chitin, Zuckern, organischen Phosphaten und Harnstoff.

Schließlich scheinen Fungizide auch das Pflanzenwachstum zu fordern, und dies nicht nur durch Eliminierung von Pflanzenschädlingen. Demgegenüber steht die Beobachtung, daO die Rhizosphärenflora so in Mitleidenschaft gezogen werden kann, daB die pathogenen Organismen in ihrem Invasionsvermögen gestärkt werden.

Die langfristige Wirkung von Fungiziden auf Boden und ihre Eigenschaften ist durchaus noch lückenhaft. Wenig bekannt ist auch über die günstige bzw. ungünstige Wechselwirkung von Fungiziden mit anderen Pestiziden in Boden. Der steigenden Pestizidanwendung im Rahmen der Nahrungsmittelversorgung mus künftig ein verstärkter Informationsstrom über die Wirkungsweise und Auswirkungen dieser chemischen Mittel gegenüberstehen. Eine Integration und Auswertung dieser Erfahrungen und Kenntnisse ist dam dringend erforderlich.
Die Aussagekraft von Gefäßversuchen im Vergleich zu Feldversuchen
Authors: Große‐Brauckmann E.
Published: February 2007

The worth of pot experiments for use in comparison with field trials

In pot experiments most growth factors are at an optimal level. As a result, plant yields often approach the maximum that is genetically possible. The application of pot experiment results to field conditions using pot surface area as a basis of conversion calculations is therefore questionable.

In this paper, data of pot experiments are presented in which competition, as occurs as crop stands in the field, has been simulated by close placement of pots in a special revolving frame structure. Using this set‐up, yields were obtained that corresponded to field grown crops provided that the total area within the frame was used in the conversion calculation and not the pot surface area.

Using the area within the frame as a basis of conversion it was found that the amount of fertilizer applied, nutrient uptake, the number of ear bearing tillers and the thousand‐grain weights were all similar to values obtained in field practice. The ground surface area is thus a suitable conversion factor for the comparison of pot and field experiments.
Auswirkungen der Gamma‐Bestrahlung und Pasteurisierung von Klärschlamm auf seine mikrobiellen Eigenschaften und die Mineralisierung im Boden
Authors: Th. Beck , Schurmann G. , Süß A.
Published: February 2007

Effect of γ‐irradiation and pasteurization of sewage sludge to the microbiological properties and the mineralization in soil

Hygienic aspects of sewage sludge application in agricultural practice are of increasing importance. Because parasites are extremely sensitive to γ‐irradiation a dose of 300 krad is equivalent to pasteurization. The total bacteria count of the sewage sludge is reduced by this dosage by 90 to 99%. Enzymic activity is reduced after radiation at a rate of about 39%. Especially amylase, catalase, and alkaline phosphatase are extremely sensitive to irradiation. Mineralization studies of sewage sludge with different pretreatments in different soil types indicated no significant differences.
Einfluß von Meliorationsmaßnahmen auf die kleinräumliche Variation von Waldbodeneigenschaften
Authors: Rehfuess K. E. , Kantarci D.
Published: February 2007

Influence of amelioration procedures on the small scale spatial variation of forest soil properties

After clearcutting, a podzol‐pseudogley derived from silty loam covering clay and a podzolic brown forest soil of sandy texture were treated as follows: CaPMg‐fertilization either alone or combined with tilling (after herbicide spray) or ploughing (after mechanical stump extraction); planting of young pines, fertilization with N in the third growing season.

Eight years after initiation of the trials, the coefficients of variation for stoniness and bulk density didn't differ between treatments. On the other hand there was clear evidence, that the clearcutand the subsequent amelioration techniques had increased the variability of the organic floor weight as well as of the pH, the carbon and nitrogen contents of the top mineral soil. These effects presumably are due to an irregular mixing of fertilized raw humus and A‐horizon material with subsoil layers by harvesting procedures, tilling or ploughing and bioturbation.
The nature of amorphous materials in alluvial soils
Authors: Rao T. V. , Singh Gurcharan , Krishna Murti G. S. R.
Published: February 2007

Die Natur des amorphen Materials in alluvialen Böden

Die Natur von amorphem Material in der Tonfraktion (≤2μ) einiger alluvialer Böden Indiens wurde untersucht. Die Bodentone hatten beträchtliche Anteile an Smectit (22–40 %), Illit (10–28 %), Kaolinit (13–18 %) und Quarz (22–40 %). Das amorphe Material wurde auf der Basis des von Krishna Murti et al. (1976) vorgeschlagenen Modells charakterisiert. Der berechnete OH‐Wasser‐Gehalt betrug durchschnittlich 15,7 %, die Kationen‐Austauschkapazität (gemessen bei pH 7,0) variierte von 65,2 bis 255,3 mval/100g und zeigte eine hohe negative Korrelation zu der äußeren Hydroxyaluminiumpolymer‐Komponente, die die Brauchbarkeit des Modells für das amorphe Material in diesen Böden bestätigt.
Entstehung und pedologische Wirkung glaziärer Frostspalten einer norddeutschen Moränenlandschaft
Authors: Blume H.‐P. , Hoffmann R.
Published: February 2007

Formation and pedological influence of glacial frostwedges of a moraine landscape in the north of Germany

Glossudal‐soilscapes of West‐Berlin show a net of frost cracks filled with sand. We think that cracks were filled by wind blown sand during the Pommern‐phase of the Weichselglaciation. Later on frost action and sedimentation of aeolian sand changed with each other under periglacial conditions followed by clay migration, mainly under holocene conditions. Sand wedges arise the variability of oecological conditions.