Wurzelstudien und Phosphat-Aufnahme von Weidelgras und Rotklee unter Feldbedingungen

Root studies and phosphorus uptake of rye-grass and red clover under field conditions Root parameters (fresh weight, density, surface, length, cation exchange capacity) and phosphate uptake were studied with rye grass and red clover, grown in the field on a brown podsolic soil. In all root parameters, ry grass was superior to red clover. Also, phosphate uptake of rye grass was higher than that of red clover. The greatest difference between both species was found in root length, that of rye grass being about five times longer than that of red clover. Rye grass had longer root hairs than red clover; whereas root diameter of clover was about twice as thick the average rye grass. Significant correlations were observed between root parameters and phosphate uptake in the plants studied. The highest correlation coefficients were obtained for the relationship P-uptake versus root length (clover 0.91***, grass 0.87***) and P-uptake versus root fresh weight (clover 0.92***, grass 0.88***). The phosphate uptake per unit root parameters was significantly higher in red clover, compared with rye grass, for the parameters root fresh weight, cation exchange capacity and root length. Because of this high P-uptake rate for clover it is assumed that clover also requires a higher P-concentration in soil solution as compared with grass. Thus grass may still grow with low P concentrations in the soil solution without P deficiency at which clover cannot grow. It is for this reason that in mixed swards clover is depressed by grass, if the available P in the soil is low.     

Variabilität der Sulfatsorption in einem Gley-Podsol aus Sand unter Kiefernforst

Variability of sulfate sorption in a sandy Gleyic Podzol under a pine stand In acid forest soils sulfate can be stored by sorption processes. We studied the vertical heterogeneity and the horizontal variability of sulfate sorption in a sandy forest soil under a pine stand. Disturbed soil samples were taken from the horizons of a Gleyic Podzol (vertical heterogeneity). From a 120-m transect, 25 soil samples were taken from depth increment 35—50 cm and 65—80 cm at 5-m intervals by means of a hand auger (horizontal variability). In batch experiments, sulfate sorption isotherms were measured for all profile and transect samples. The Freundlich equation is suitable to describe the individual isotherms. The sulfate sorption isotherms show considerable differences in the horizons of the profile, systematic relations between the isotherm parameters and soil properties are not obvious. In order to quantify the spatial variability of the sulfate sorption isotherms, a scaling technique is used. The spatial distribution of scale factors for depth 35—50 cm along the transect reveals a periodicity of about 17 m length. The same recurrent pattern is also identified in the spatial distribution of the cumulative sulfate deposition by canopy throughfall along the transect, and in the spatial distribution of contents of iron and aluminium oxides soluble in oxalic acid at depth level 35—50 cm. This does, however, not refer to organic carbon content and pH at this depth. From these results it is concluded that in this soil at depth 35—50 cm oxide contents are related to the amount of sulfate deposition by throughfall. In spatial ranges with high sulfate and thus acid deposition, oxide contents of the soil are decreased by accelerated podzolization, and therefore, also the sulfate sorption of the soil is low in these ranges. The period length of this recurrent pattern of about 17 m is probably only an apparent period length that results from aliasing, because a very probably real periodicity of 3—4 m length, related to the canopy edge distribution of the pine trees along the transect, is sampled at an interval of 5 m. In the subsoil (65—80 cm depth) such relations could not be detected.     

Die Verteilung der stabilen Kohlenstoffisotope 13C/12C in einem Pseudogley unter Wald

The distribution of the stable carbon isotopes ¹³C/¹²C in a pseudogley under forest In a pseudogley, a soil with purched surface water, the δ¹³C-values of organic carbon have been analysed. A linear depletion of 1.5% has been observed in the A_h-horizons ranging down to 18cm. The following A_eS_w- and S_w-layers display an enrichment which amounts to 2% at a depth of 55cm. Below this depth in the IIS_d-layers the δ¹³C-values are almost constant showing a value of about -25.4%. Model calculations indicate that displacement effects may be responsible for the depletion of the ¹³C-isotope in the A_h-horizons, while mineralization should account for the enrichment of the ¹³C-isotope in the adjoining S_w-horizons.     

Zur Stickstoffdynamik unter Exkrementflecken bei Weidegang

Nitrogen Dynamics Under Excrement Patches in Pastures Soil mineral nitrogen contents in relation to time were measured under excrement patches on three pastures in Lower Saxony. The highest values were found under patches of urine on a pasture grazed by suckling cows. The herbage dry matter of that pasture showed a crude protein content of 19 %. The contents of mineral nitrogen under urine patches were less on a comparable pasture utilized by milking cows. The concentrations were still less on a cow grazed pasture, which remained unfertilized over a period of ten years. The content of NH₄-N under urine affected areas increased distinctly in the whole soil profile, within one day of deposition. High NO₃-N concentrations were found even in deeper soil layers after one week. The nitrogen concentrations under patches of urine approximated the values under not urine affected parts of the pasture within three months. The increments of mineral nitrogen under patches of faeces were insignificant.     

Berechnung der bodengrundatmung unter feldversuchsbedingungen

Nach Abbau aller Primärsubstanzen geht der Boden in den “Grundatmungszustand (GRA)”; über.—Am praktischen Beispiel einer Feldversuchsparzelle werden die in zeitlicher Folge gemessenen C_CO2‐Intensitäten zunächst in ihrer Temperaturabhängigkeit (T) quantifiziert (nach van't Hoff bzw. Arrhenius). Danach erfolgt die Ermittlung der Abhängigkeit der GRA von der Bodenfeuchte (W).—Nach der nun möglichen Korrektur der gemessenen C_Co₂—Werte auf konstante T und optimalen Wassergehalt (W_opt) konnte der eigentliche “Substratabbau”; der GRA als (Pseude‐) Reaktion I. Ordnung isoliert werden. Mit Hilfe der daraus abgeleiteten Parameter (Reaktionsgeschwindigkeitskonstante und Mineralisierungspotential) ließen sich, unter Nutzung der abgeleiteten T‐ und W‐Funktionen, die natürlich variierenden Cco₂‐Werte der Parzelle berechnen und mit den tatsächlich gemessenen vergleichen. ‐Diskutiert werden u.a. die “Doppeltlogarithmische Linearität”; als Kriterium für die GRA sowie die Überlagerung mehrerer Reaktionen erster Ordnung.     

Mechanismen der aggregatstabilisierung in einem tonboden mittels branntkalk

In the present paper, investigations are described which were conducted to find out how stabilization observed in a field experiment was effective if the applied lime was very largely in contact with the surfaces of aggregates.Shearing of undisturbed samples from the field experiment showed a decrease of maximum shearing resistance in the limed soil. Ultimate strength, however, was not measurable in the unlimed control because no yield-stress-equilibrium was reached.In laboratory samples (10–50 g CaO/1000 cm³ of soil) an increase of the angle of internal friction and a simultaneous decrease in cohesion were found with increased application of lime. Again no ultimate strength could be measured for the unlimed samples.Compaction tests on laboratory samples showed significant differences in structure that were in line with increasing resistance of the sample to shearing.These results suggest that the additional stability of the limed aggregates was due to preserving aggregate boundaries. This helped to avoid the development of neutral stresses in the aggregates when under load. The effect was found to be more strongly expressed in laboratory samples because their aggregates were smaller than those in the field soil.     

Zur Darstellung von Schichtwechseln in periglazialen Decklagen des Bayerischen Waldes unter besonderer Berücksichtigung der Mittellage und ihrer Eigenschaften

On the presentation of layering in periglacial slope deposits Methods are discussed that appear suitable for more precisely subdividing periglacial slope deposits and their material composition beyond the level of field observation. The study area is the Bavarian Forest region and its surroundings in eastern Bavaria. As a first step significant information concerning layer changes and material characteristics is derived from grain-size distribution. For methodological reasons a further mathematical abstraction in the sense of layering coefficients is not feasible, however. Heavy mineral spectra allow the distinction of layers with eolian influence from loess-free layers and point out material relationships. In addition they characterize the degree of weathering of both the periglacial deposits and the underlying bedrock. The Laacher See tephra as a means of dating is unfortunately absent in the study area. Principal and trace elements of the fine soil fraction are sensitive indicators of material change. The study of pedogenic oxides of various fractions reveal that the substrate of the periglacial slope deposits is composed of material modified by soil-forming processes prior to sedimentation. This is especially true for the middle layer, the analysis and origin of which stand at the center of this contribution. X-ray diffraction analysis of the clay fraction helps differentiate pedogenic transformations and sedimentary characteristics. It equally supplies evidence of considerable eolian influx of clay and silt in the main and the middle layer. The diagnostic characteristics of the individual layers are presented; peculiarities of the middle layer as well as divergencies from the criteria found in the literature are dicussed.     

Zur Technik der Sortimentserhaltung

Zusammenfassung Die Sorten eines Sortiments durch lange Zeit unverändert zu erhalten, bietet erhebliche Schwierigkeiten. In manchen Fällen (gewisse Fremdbestäuber) ist es überhaupt unmöglich, in anderen gelingt es nur für kurze Zeit, allgemein nur für bestimmte Merkmale, für die es praktisch durchführbare Kontrollmöglichkeiten gibt.Es werden einige der in Gatersleben angewendeten einfachen Verfahren beschrieben, um die durch natürliche Auslese, ungewollte Kreuzungen, Auftreten von Mutationen sowie mechanische Vermischungen eintretenden Veränderungen möglichst weitgehend auszuschalten. Das sind u.a. disjunktiver Anbau der Sorten, einfache Isolationen, Sicherheitsmaßnahmen bei Aussaat, Ernte und Ernteaufarbeitung. Dazu kommen allgemeine Kontrollmaßnahmen und in bestimmten Abständen durchgeführte Echtheitsprüfungen durch Vergleich mit dem Sortimentsarchiv.     

Analyse der K-Düngewirkung an einem Humuspelosol-Standort

Analysis of the K-fertilizing effect on a Humuspelosol site The result of a K-fertilizing experiment with a nearly pure cereal rotation on a Humuspelosol (eutric Cambisol) 1973 poor in ?available”? K and strongly K fixing (see Fig. 1) was analysed by investigating plant and soil samples taken 1981 and 1982. About 1200 kg K₂₀/ha were fixed, thus did not change the ?available”? K, but restored the reserves to such an extent that the plants were supplied sufficiently from it. Amounts exceeding 2400 kg K₂O/ha could not be held in the main rooting space (0–40 cm). Even 180 kg K₂O/ha/a in the course of the experiment restored the reserves sufficiently, leading to an (at best) normal fertilizer requirement at this site (with low Mg supply possibly limiting the yields), despite its still low content of ?available”? K. Apparently, here the LUFA threshold values are too high and/or the lactate method is not a suitable basis for statements about the fertilizer requirement.     

Untersuchungen über die Freisetzung der Bioelemente aus der organischen Substanz der Humusauflage in einem Buchenbestand

Investigations on the Transfer of Bioelements from Organic Matter to Soil Solution in the Humus Layer of a Beech Stand Monthly and annual fluxes of bioelements were measured in two levels: (a) at the soil surface (= input) and (b) at the lower boundary of the humus layer (= output) by determination of amount and concentration of the precipitation (canopy drip), of the litter and of the seepage. Seepage was collected with funnel lysimeters. By comparison of both fluxes (input-output-analysis) for some bioelements mathematical equations could be derived which describe the transfer of these elements from organic matter to soil solution. The results are explained as consequence of the different bonds of the elements in leaf tissues and in humus substances.     

Zur allgemeinen Systematik der Kulturpflanzen II

Ohne ZusammenfassungI in: Die Kulturpflanze 1 (1953 138–155.     

Zur Nutzung vonAllium-Wildarten der mongolischen Flora

Zusammenfassung Allium-Arten gehören zu den regelmäßig und traditionell von der mongolischen Bevölkerung genutzten Wildpflanzen, die vor allem als Würzmittel für die sonst vorzugsweise auf tierischen Produkten beruhende Kost dienen. Besondere Bedeutung haben dabeiA. altaicum, A. victorialis undA. ramosum, bei denen die Sammlung von Zwiebeln bzw. oberirdischer Pflanzenteile nicht nur für den individuellen Bedarf, sondern auch für die Marktversorgung erfolgt. Als Ausgangsmaterial zur Herstellung eines Winterkraftfutters sindA. polyrrhizum undA. mongolicum in den Halbwüstengebieten der MVR von hohem wirtschaftlichem Wert. Bei einigen Arten(A. altaicum, A. macrostemon) hat die intensive Nutzung zur Verringerung der natürlichen Bestände geführt.

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The use of wild species ofAllium in the mongolian flora

Summary Wild species ofAllium have been used regularly and traditionally by the Mongolian people mainly as spice plants for their food which is based mostly on animal products. The most important species areA. altaicum, A. victorialis andA. ramosum, gatherings of their bulbs resp. overground parts does happen not only for individual purposes but for the market, too. FromA. polyrrhizum andA. mongolicum dry pellets are prepared as forage (mostly for sheep) for the winter time, therefore these taxa are economically very useful especially in the semidesert regions of the country. Extensive collecting resulted in population shrinkngs of some species(A. altaicum, A. macrostemon).

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Allium

Allium , . A. altaicum, A. victorialis A. ramosum, , .A. polyrrhizum A. mongolicum . (A. altaicum, A. macrostemon) .

     

Zur Physiologie und Biochemie der Glykosidbildung

Zusammenfassung An Hand der Literatur und von eigenen Versuchen wird die Physiologie und Biochemie der Bildung von Glykosiden erörtert. Im Vordergrund stehen dabei einfache Phenolglykoside. Es hat sich gezeigt, daß die Glykosidbildung in starkem Maße zu Zeiten einer erhöhten Stoffwechselaktivität erfolgt und vornehmlich in grünen Blättern ohne Mitwirkung der Wurzel abläuft. In biochemischer Hinsicht kann die Glykosidbildung als Gruppenübertragungsreaktion charakterisiert werden, bei der der Zucker durch Anknüpfung an Uridindiphosphat aktiviert werden muß.

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Summary With regard to citations in literature and own investigations the physiology and biochemistry of glycoside biogenesis are discussed. Simple phenolic glycosides are considered preferably. It could be shown that glycoside formation is taking place to a considerable extent at the time when the metabolic activity is increased and that this reaction occurs especially in green leaves without interaction of the root. With regard to biochemistry glycoside formation can be characterized as a group transferring reaction, in wich the sugar unit must be activated by uridine diphosphate.

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. . , , . , ; .

     

Zur Untersuchung der verschiedenen Formen von Chlorophyll in der lebenden Pflanze durch Anwendung der Derivativ-Spektrophotometrie

Zusammenfassung Die Anwendung der Derivativ-Spektrophotometrie ermöglicht eine bessere Auflösung der sich sehr stark überlagernden Absorptionsbanden der verschiedenen Chlorophyll a-Formen in vivo im Vergleich zur üblichen spektroskopischen Technik. Untersuchungen von Gleichungen zur Beschreibung der Form von Absorptionsbanden und ihren 1. und 2. Ableitungen führen zu dem Ergebnis, daß sich durch die Differentiation die Halbwertsbreite verringert und damit das Auflösungsvermögen erhöht. Die 2. Ableitung zeigt sich dabei der 1. Ableitung überlegen.Apparative Möglichkeiten für die direkte Registrierung differenzierter Absorptionskurven werden untersucht. Unter Anwendung eines dabei auftretenden einfachen Prinzips wurde eine Apparatur gebaut, mit der neben der Extinktion und ihrer 1. Ableitung auch die 2. Ableitung nach der Wellenlänge registriert werden kann, die bisher nicht für Untersuchungen der Blattpigmente herangezogen wurde.Einige mit diesem Gerät aufgezeichnete Spektren demonstrieren die Vorteile der Derivativ-Spektrophotometrie, insbesondere für die Untersuchung der photosynthetischen Pigmente in vivo.

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Summary The strongly overlapping absorption bands of chlorophyll a forms in vivo are better resolved by derivative spectrophotometry than by ordinary absorption spectra. It was possible to demonstrate by eximation of equations describing the form of absorption bands and their first and second derivatives, that the half width of an absorption band is reduced by differentiation and therefore the resolving power is increased. The second derivative is shown to be superior to the first one.By examining apparative possibilities for recording directly differentiated absorption curves a simple principle was found, according to which an apparatus was constructed, that allows to record the direct absorbance spectrum, its first and its second derivative.Till now the second derivative of the absorption spectrum is not used for studying the leaf pigments.Some spectra, recorded with this apparatus, demonstrate the advantages of derivative spectrophotometry, especially for analysing photosynthetic pigments in vivo.

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am ¶rt;au « » a in vivo . , , , , , . , . . , ¶rt; , . , « » in vivo.

     

Untersuchung der potentiellen Stickstoff-Mineralisation in Trumao-Böden und einem Pseudogley

Total porosity and pore size distribution in untilled and tilled loess soils . Soil core samples were taken from untilled and tilled soils of a no-tillage experiment to determine total porosity and pore size distribution. The soil samples were collected at short time intervals during 1969–1971 from 2–6 cm depth of a Grey Brown Podzolic Soil (Typudalf) deriverd from loess. 1. Total porosity differed in untilled and tilled plots on the average by 4.7 vol.% (table 2). The seasonal changes are more pronounced on the tilled soil. Higher values of total porosity are observed during spring and fall, as compared to summer. Values are influenced by soil cultivation, rainfall and green manure crops (fig. 1a, b). 2. The changes of the fraction of large pores (> 30 μ), expressed on a volume basis, are similar to the changes in total porosity in direction but greater in extent. On the contrary the seasonal changes of the fractions of medium pores (3–30 μ), small pores (0,2–3,0 μ) and very small pores (< 0, 2 μ) appear to be independent from changes in total porosity (fig. la, b). 3. Fig. 2, showing the relation between total porosity and pore size distribution, may induce the wrong impression, that a decrease in total porosity results in an increase of the quantity of small and very small pores, accompanied with an excessive reduction of the quantity of large pores. If this relation is based on weight (100 g of solid soil particles) and not on volume (100 cm³ of soil particles and pores), it becomes clear, that compacting and loosening the soil investigated affect mainly the amount of large pores. 4. The seasonal changes of soil water content in the field influence pore size distribution. Under the condition of constant total porosity increasing water content at sampling date induces a pore size redistribution in favour of the pores > 300 μ and 1,5–3,0 μ (table 3). 5. A decrease in total porosity does not induce an increase in the homogeneity of the soil investigated (fig. 3). 6. The average total porosity of the untilled and tilled soil is near the lower and upper limit respectively of the range, which is considered to be the optimum for air capacity.     

Zur Genese von Schwarzerden auf der Sontheimer Hochterrasse in der Donauniederung bei Ulm

Pedogenesis of chernozems in the upper river terrace of the Danubian river near Ulm (South West Germany) The “chernozem-like” soils in the upper river terrace of the Danubian river near Ulm (FRG) were examinated. Field analyses as well as soil physical and chemical, clay mineralogical and pollen analyses were carried out. The parent material of the soils was identified as loess, on the basis of its texture, clay mineral composition, structure, carbonate content, the presence of loess molluscs, and the location on an upper river terrace with loess findings in the surrounding. Characteristic pedogenetic processes, such as deliming, silicate weathering, formation of oxides and hydroxides, neoformation of clay minerals and clay translocation prove a non-groundwater-influenced development of the soils within at least the last 8000 years. Therefore an accumulation of organic matter under anaerobic conditions during the peat formation in the lower river terrace nearby was not possible. According to this finding, it can be deducted that the humus accumulation may be due to influences of continental climate and forest steppe during the preboreal period, whereby the humus horizons were formed at deeper horizons through bioturbation. After the groundwater level was raised in boreal age, the steppe stage of the soils had ended and the fluctuating levels of groundwater, rich in carbonates, stabilized humic substances. Thus strong degradation of the soils to date was prevented. Therefore the soils under study could be classified as gleyic Chernozems or luvic Phaeozems.     

Zur Kenntnis der Chromoplasten vonCyphomandra betacea Sendtn

Ohne Zusammenfassung