Untersuchungen über den Einfluß von Gibberellinsäurespritzungen auf den Ertrag,die Anatomie der Wurzel und die Karotinverteilung bei Karotten

Investigations on the Influence of Gibberellic Acid Treatments on Yield, Root Anatomy and Carotene Distribution of Carrot Plants . Application of GA₃ onto the shoots of carrot plants increases shoot growth whereas root growth was reduced. Furthermore, due to the GA₃-application carotene content (Table 2) in the shoots was increased and decreased in the roots. Anatomical investigations of the roots revealed that apparently the reduction of root growth after GA₃-application was due to a decrease of phloem oriented cambial activity (Table 3).     

Zelluloseabbau während der Heißrotte von Siedlungsabfällen

Degradation of cellulose during high-temperature composting of municipal wastes Model experiments were carried out to investigate the breakdown of cellulose during the decomposition of municipal wastes at high temperatures. At 70°C only small amounts of cellulose were decomposed. But a very considerable breakdown of cellulose was observed at temperatures of 65°C and below, i.e. at temperatures suitable for the growth and activity of thermophilic microorganisms.     

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.     

Wirkung der Kaliumdüngung auf die Kaliumverfügbarkeit in der Rhizosphäre von Raps

Influence of potassium supply on the availability of potassium in the rhizosphere of rape (Brassica napus) Potassium depletion of the soil in the proximity of roots was studied in order to obtain quantitative information on the availability of potassium. For this purpose rape seedlings were grown in pots which separate roots from soil by a fine meshed screen; root hairs penetrated the screen. The soil adjacent to the screen was sliced by microtome into layers about 0.1 mm thick which were separately analysed for k. Plant roots strongly depleted the soil in their proximity; further distant ranges remained unchanged. A loess derived loam, brought to different levels of exchangeable K by precropping or K application, was equally depleted to 150 μmoles/100g soil at the root surface. Therefore, the quantity of K released from this source increased with initial K level. In addition, the distance of the depletion zone extended with K level from 4,6 to 6.3 mm from the surface of the root cylinder. Hence, the volume of soil contributing K to the root increased from 0.7 to 1.2 cm³ per cm root length. The combination of these two parameters, i.e. the quantity of exchangeable soil K released per unit of root length increased by a factor of 20 whereas exchangeable soil K was raised by a factor of 4.5 only. K uptake of the plants after 4 days was in agreement with the depletion of exchangeable soil K in the high K treatment only. The other treatments had obviously taken up considerable percentages of nonexchangeable K. This fraction was released from the soil ranging less than 1.5 mm from the root. The distance of the K depletion zone was also extended by application of NaCl and MgCl². Because of cation exchange, K concentration of the soil solution was increased, K buffer power decreased and, therefore, K diffusion was enhanced. It is concluded that plants in the field do not uniformly deplete the total rooted soil volume. Whereas roots in their proximity strongly deplete the soil including parts of nonexchangeable K they do not even use exchangeable K in a slightly greater distance. The quantity of K available per unit of root length is, therefore, determined by both - the degree of soil K depletion at the root surface and -the distance of the depletion zone, i.e. the volume of soil that contributes K to the root. Either factor was markedly affected by the level of soil K and thus by K application.     

Über Sorption und Wirkung von Blei auf die biologische Aktivität terrestrischer Humusformen

Lead sorption and effect of lead pollution on biological activity of different types of humus forms Effects of Pb(NO₃)₂ on biological activity (e. g. respiration and enzyme activity) of mull, moder and mor soils were investigated under controlled laboratory conditions. Lead sorption capacity of investigated humus forms decreased in the order mull > moder > mor. Soil respiration was inhibited after addition of 10 mg Pb/g soil at lead concentrations > 1 μg Pb/ml of soil solutions of the mor and moder profiles. Highly significant positive regression coefficients were obtained for decreases in soil respiration and decreases in dehydrogenase-, phosphatase- and arylsulfatase activities of O-horizons. It is assumed that minor enzymatic acitivities after lead addition result from its effect on enzyme producing organisms. After additions of 200 mg Pb/g soil biological activities of investigated humus layers were also affected by a marked increase of acidity of soil solutions. This ?secondary”? effect was also obtained using Ca(NO₃)₂ in pollution experiments.     

Über die Wirkung von Pydanon auf Halmlänge und Ertrag von Winterweizen und Winterroggen

Influence of Pydanon upon Stalk Length and Grain Yield of Winter Rye and Winter Wheat. . In pot experiments with three varieties of winter rye a considerable reduction of stalk length was obtained by the growth regulator Pydanon without a significant reduction of grain yield. The necessary amount of active substance however was rather high and the period of time for optimal application was limited. Winter wheat did not respond to Pydanon.     

Untersuchungen über die Auswirkung von Bestandskalkungen auf die Bodenvegetation in Fichtenforsten

Zusammenfassung In anthropogenen Fichtenforsten wurden die Auswirkungen von Kalkdüngungsversuchen auf die Bodenvegetation nach zehn Jahren untersucht. Eine auffällige Begrünung hebt die gekalkten Flächen deutlich von den vegetationsarmen, fast nur von azidophilen Moosen besiedelten ungedüngten Nullparzellen ab.Neben regelmäßig auftretenden, meist stickstoffliebenden allgemeinen Kalkungszeigern wieEpilobium montanum oderMycelis muralis treten nach Kalkung Trennartengruppen auf, die Rückschlüsse auf Standort, geographische Situation und Höhenstufe zulassen. Sie enthalten überwiegend Laubwaldelemente, ohne daß sich jedoch die spezifische Artenkombination der natürlichen Laubwaldgesellschaft des Standortes vollständig einstellt.

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Summary In anthropogeneous spruce forests the effects of experments with quicklime fertilizing on the vegetation were studied after ten years. A striking verdure differs the calcium fertilized areas significantly from the unfertilized plots which are poor in vegetation and only covered by acidophile mosses.In addition to regularly appearing mostly nitrophile general calciumfertilizing indicators as e. g.Epilobium montanum orMycelis muralis after calcium-fertilizing groups of differentiating species can be noted which allow conclusions concerning position, geographical situation and height-level of vegetation. They mostly contain elements of woods of deciduous trees. The specific combination of species of natural communities of woods of deciduous trees, however, does not appear completely.

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Über die Wirkung von Phenylphosphoniumsäure auf Ertrag,Korn/Stroh-Verhältnis und Stickstoffaufnahme bei Getreide

The Effect of Phenyl Phosphonic Acid upon Yield, Grain/Straw Ratio and Nitrogen Uptake of Cereals . The investigations presented confirm positive effects of phenyl phosphonic acid upon grain/straw ratio obtained by other authors. This improvement however resulted from a decreased yield of straw and not from an increased yield of grain, and was not accompanied by reduction of straw length. It is therefore of no advantage. An increase in the yield of grain and increased nitrogen uptake reported by other authors due to the application of phenyl phosphonic acid were not confirmed by the results of the present study.     

Untersuchungen über den Einfluß des Kinetins und des Eisens auf den Nukleinsäure- und Proteinstoffwechsel von Karottengewebekulturen

The Influence of Kinetin and Iron on Nucleic Acid and Protein Metabolism of Carrot Tissue Cultures Carrot-root tissues cultured in a nutrient solution containing Kinetin had a high rate of cell division, that led to an undifferentiated callus, and a relatively low DNA content per cell. The same tissues growing without Kinetin had a smaller rate of cell division and a higher DNA content, and showed the ability to form roots. By addition of ³²P to the nutrient solution, the cultures growing with Kinetin showed a higher specific activity of DNA than those growing without Kinetin. From previous experiments and results of other workers the possibility of the occurence of a metabolic labile DNA fraction in the cultures which grew without Kinetin is discussed. A comparison between the influence of iron and Kinetin on cell division activity, root formation, DNA, RNA and amino acid content of the tissue cultures was made on a cell basis. Iron deficiency or absence of Kinetin in the nutrient solution reduced the cell division activity of carrot tissue cultures and increased the content of DNA, RNA and soluble amino acids. The protein content was reduced by iron deficiency but was increased by the absence of Kinetin. Cultures, growing without Kinetin were able to form roots, while those, growing in an iron deficient medium were unable to show the latter phenomenon.     

Über die auswirkung quartärer tektonik auf die altpleistozänen Mittelrhein-Terrassen

Above the narrow Rhine-Valley of the Middle-Rhine-Area usually five, sometimes six Old-Pleistocene river terraces can be traced. Between Bingen and Oberlahnstein they show neither tectonic warping nor a distinct longitudinal gradient. A similar situation exists in the Lower-Middle-Rhine-Area. From this follows that during the Quaternary an “en bloc uplift” of the central Rheinische Schiefergebirge along the Rhine-Valley took place. Only the basin of Neuwied developed differently. As the river-terraces must have had a longitudinal gradient in the beginning, a stronger postsedimentary uplift of the northern area has to be taken into account.     

Untersuchungen über den N-Stoffwechsel und den N-Transport dekapitierter Wurzeln

Investigations on the N-metabolism and N-transport in decapitated roots Experiments were carried out on roots and bleeding sap of decapitated pumpkin plants supplied with nitrate-N to investigate the nitrogen metabolism and transport of nitrogen in relation to the time after decapitation. 1. Up to two hours after decapitation absorbed nitrate was metabolized into organically bound nitrogen. The rate at which this occurred decreased with time and subsequently the turnover was strongly depressed. 2. 30 free amino acids were detected in the bleeding sap. These amounted to 25% of the organically bound nitrogen. Amino acids of the glutamate family dominated, especially glutamine and arginine. In the course of the first hour, the relative proportion of glutamine-N increased; at the same time the total concentration of amino acids was slightly reduced. More pronounced shifts in this fraction were observed after two hours, indicating the occurrence of catabolic processes. In the root neither the total concentration of free amino acids nor the composition of this fraction was altered within the two hour period. However, the composition differed substantially from that of the bleeding sap. 3. By aid of gel filtration, compounds in the bleeding sap were detected with molecular weights from 200 to 5000 and with free NH₂-groups. 4. Up to the end of the two hour period the activities of nitrate reductase, glutamate-dehydrogenase and glutamate-oxalacetate-transaminase remained almost fully functional. A slight and reversible decrease in the activity of nitrate reductase in the roots in the first half hour proved to be coincident with rising rates of nitrate accumulation and strongly decreasing rates of organically bound N accumulation. The results are discussed in relation to the interruption of carbohydrate supply to the root following decapitation. In addition, differences are pointed out between the contents of nitrogen compounds in the roots and in the bleeding sap.     

Vergleichende Untersuchungen über das unterschiedliche Wachstum von Getreide im Feldbestand und in Gefäßen

Comparative investigations on the different growth of cereals in the field and in pots . Yields from pot trials, referred to soil surface area or soil volume, are generally higher than those obtained from field trials. The transposition of pot trial results to field conditions is thus debatable. Yields of summer wheat, obtained in the trials, described in this paper, were with the same fertiliser level about 47% higher in the pot trials than in the field. Additional nitrogen fertiliser even led to pot yields about 170% above the field yields. Phosphate fertiliser alone had no effect with the soils used. Nitrogen and phosphorus, on the other hand, particularly improved yields, so that pot yields in question were about 224% higher than those in the field. The phosphate content of the grain from pot and field trials only varied slightly, whilst in the straw it was greatly dependent on the yield and fertiliser applied. The lactate-soluble phosphate towards the end of the trials also largely corresponded to the uptake and fertiliser level. Ear number in the pot trials was higher than in the field trials by a factor of 2.5–3.1., depending on fertiliser application. The corn/straw ratio was approximately the same at 1:1.66 with the same fertiliser in both field and soil. With the higher fertiliser levels, usual in pot trials the ratio narrowed to 1:1.06. The comparatively higher pot yields are therefore in the first place the result of higher fertiliser applications. Competition for light and water, diminished in comparision to field plants, of pot plants plays a small role under normal weather conditions, on the other hand, but becomes active with much higher nutrient supplies.     

Sorption und Wirkung von Arsen auf die mikrobielle Aktivität von Waldhumusformen

Arsenate adsorption and effects of arsenate pollution on microbial activity of different types of humus soils Perfusion experiments using Na₂HAsO₄ were carried out in order to investigate adsorption and effects of arsenate on microbial activity of L-, O-, and A-horizons of a mull, a moder, and a mor soil. Arsenic adsorption of mineral A-horizons was positively influenced by their contents of amorphous Al- and Fe-oxides. It is assumed that arsenic was mainly precipitated as Al-, Mn- or Ca-arsenate in the organic layers during the perfusion experiments. The Freundlich equation was valid to describe As-adsorption of all layers under investigation. Microorganisms seemed to be very tolerant to arsenate pollution. Soil respiration and enzyme activities were reduced when liquid concentrations exceeded 8 μg As/ml. Extremely high As-additions (up to 10 mg As/g) did not reduce microbial processes to a greater degree than lower ones of 0,5 mg As/g.