bluuebunny/crossref_metadata_2025_split huggingface dataset:
Der Einfluß von Niederschlag und Höhenlage auf den Humusgehalt ostafrikanischer Böden
Authors: Jagnow G. 
Published: February 2007

The influence of precipitation and altitude on the humus content of East African soilsPositive correlations were found between the log of the carbon and nitrogen content of the 0–15 cm soil layer, altitude and average annual precipitation of 20 grassland soils, 13 forest soils and 21 cultivated soils at altitudes of 10–2840 m and a precipitation of 380–2410 mm in Kenya, Tanzania and Uganda. For each of the soil groups equations with the two variables altitude and precipitation were derived, which accounted for 76–93 per cent of the variation of the carbon (0,42–5,62%) and nitrogen (0,04–0,71%) content. There was no correlation between altitude, precipitation and the C/N ratio of the soils.
Reaktionen von Ca‐Montmorillonit und Ca‐Vermiculit mit Kohlensäure
Authors: Veith J. , Schwertmann U. 
Published: February 2007

Reaction of Ca‐Montmorillonite and Ca‐Vermiculite with CO2The treatment of Ca‐montmorillonite and Ca‐vermiculite with carbonic acid (Pco2 = 2 atm) has shown the following results:In the pH range of ± 3.9–6.0 Ca is exchanged by H directly only on pH dependent (variable) charge sites (Cav), whereas, Ca on permanent charge sites (Cap) is exchanged only by lattice cations mainly Al released by proton attack. Therefore, with regard to proton uptake from carbonic acid the two Ca‐clays behave as extremely weak acids.The exchange of Cav proceeds rapidly that of Cap much more slowly, the first one is essentially reversible the latter at least not within a short period of time. The proportion of Cav is found from a graphical extrapolation of the Ca saturation‐pH‐function (fig. 3).Al released during the initial stage of the reaction is non exchangeable, prevents the expandable minerals partly from collapsing on K tratement (verm. much more than mont.) and has an OH/Al ratio of about 2. On treating the same clay sample several times or at low suspension concentrations exchangeable Al with OH/Al = O occurs. Exchangeable hydrogen was never detected. Vermiculite is less resistent against carbonic acid than montmorillonite.The results were discussed in respect to the mechanism of release of lattice constituents and in respect to Al release under the influence of CO2‐concentrations of soils.
Der Einfluß variierter Düngergaben von Stickstoff, Kupfer und Magnesium auf den Ertrag von Hafer
Authors: Kühn H. , Judel G. K. 
Published: February 2007

The Influence of varying Amounts of Nitrogen, Copper and Magnesium on the Yield of Oat1. In pot experiments with oat high amounts of copper (500 mg) copper sulfate/pot, comparable to 50 kg (Cu/ha) together with a high nitrogen supply as calcium nitrate led to a remarkable increase in yield of grain in comparison to a normal copper fertilization (50 mg copper sulfate/pot, comparable to 5 kg Cu/ha). When using high amounts of ammonium sulfate the observed effect of high amounts of copper was only small.2. According to the results and to the copper content and copper uptake of the plant it was concluded, that nitrogen fertilization given as ammonium sulfate increased the availability of soil copper and/or fertilizer copper presumably by affecting the soil reaction. Nitrogen fertilization given as calcium nitrate therefore needs a higher copper level in the root medium either from soil or fertilizers in order to obtain the maximum yield.3. It was assumed that the form of nitrogen fertilizers was responsible for the different availability of copper in these experiments, as the amount of available copper in the soil increased with the lowering of soil pH due to ammonium sulfate addition.4. The high copper supply to the soil remarkably reduced the harmful effect of high amounts of nitrogen given as calcium nitrate but not as ammonium sulfate.5. The nitrogen fertilization with calcium nitrate, especially in combination with a high copper supply, resulted in the reducing effect of a magnesium deficiency.6. The harmful effect of high amounts of nitrogen, especially in the ammonium sulfate form, upon yield was reduced by an optimal magnesium supply.7. The results presented suggest that for evaluating the copper status of the soil and for estimating the demands of copper fertilization, soil reaction and its change by the form of nitrogen fertilizers should more be taken in consideration.
Der Einfluß der Kalium‐Ernährung auf den Gehalt und das Spektrum löslicher Aminoverbindungen in Rotklee (Trifolium pratense L.)
Authors: Koch K. , Mengel K. 
Published: February 2007

Effect of potassium nutrition on the content and the spectrum of soluble amino compounds in Red Clover1. A better K nutrition of Red Clover (Trifolium pratense) resulted in higher contents of soluble amino acids of the upper plant parts. The plants of the treatment with the highest K application showed nearly double as high contents of glutamic acid, aspartic acid, alanine and γ‐aminobutyric acid than the plants of the K0 treatment. The content of asparagine was not as much affected by the K nutrition and the content of glutamine was even lowered.2. Red Clover responded on the K treatment with its content of soluble amino compounds quite different than non leguminous plant species which show decreasing contents of soluble amino acids with an increasing K nutrition. Therefore it is concluded, that the K nutrition of legumes affects the N2‐fixation of Rhizobium leguminosarum.3. The higher contents of soluble amino compounds did not influence the protein content of the upper plant parts. But with the better K supply the yields were increased considerably and therefore also higher yields of proteins were harvested. Very low K supply resulted in a high protein content, due to an inhibition of plant growth.
Identifizierung und Bestimmung einiger Gibberelline und der Einfluß von Chlorcholinchlorid (CCC) auf das Gibberellinspektrum der einzelnen Getreidearten
Authors: Sadeghian E. 
Published: February 2007

Identification and determination of some gibberellins in the gibberellin spectrum of some cereals, als affected by CCC treatmentThe gibberellin contents of wheat, barley and oat plants, treated with CCC, were studied during the vegetative period. It was possible to identify a characteristic gibberellin spectrum for every cereal plant examined, although the variation was in a limited number of gibberellin forms. A great variation in the content of individual gibberellic acid forms was noticed, as well, among the different cereals studied. The highest content of gibberellins was found with GA3. The content of GA5 was lower than that of GA9 while was not generally higher than that of GA8. CCC‐treated cereal plants showed lower values of gibberellins when compared with those of control. On the other hand, CCC treatment did not affect the content of gibberellins in the spikes which showed a considerably high content of GA3, GA5 and GA9. A higher content of GA7 was observed in both barley and oats, but not in the case of wheat, during tillering stage. However it was difficult, from the results of the present work, to indicate whether GA7 is reponsible for the week effect of CCC obtained with both barley and oats or not.
Zur pflanzenphysiologischen Bedeutung des Selens. I. Mitteilung: Die oxydative Bildung von Selenit und Selenat und deren analytische Bestimmung in den Testsubstraten
Authors: Kramer W. , Ziechmann W. 
Published: February 2007

AbstractIn belüfteten Hydroponik‐ und Quarzsandgefäßen wurde der Lichteinfluß auf die oxydative Bildung von Selenit und Selenat aus elementarem Selen, die des Selenats aus Selenit und die reduktive Ausscheidung von elementarem Selen und Selenit untersucht. Die gebildeten Mengen an Selenit wurden nach einer 8wöchigen Versuchsdauer mit Hilfe einer Differenzmethode bestimmt.Die Einwirkung von Licht bewirkte während der Versuchsperiode eine relative Erhöhung des Selenat‐ und eine geringere Bildung des Selenitanteils bei Anwesenheit von elementarem Selen. Die zu Beginn der Oxydationsversuche zugegebene Nährlösung begünstigte unter Lichteinwirkung beim angewendeten elementarem Selen eine Erhöhung des Selenit‐ und eine Herabsetzung des Selenatanteiles.Bei der Anwendung von Natriumselenit zeigten sich in den Hydroponikgefäßen kaum Unterschiede in den Ausfällung von elementarem Selen durch unterschiedlichen Lichteinfluß und Nährlösungszusatz. Dieser kam nur bei den Quarzsandgefäßen zum Ausdruck, wo unter der Einwirkung des Lichtes ohne Nährlösung durch Vorherrschen der reduktiven Bedingungen mehr elementares Selen gebildet wurde und somit weniger Selenat vorhanden war als bei Anwesenheit der Nährlösung.
Der Einfluß von Bewässerung und Fruchtfolge auf den Humus‐ und Stickstoffhaushalt sowie die Bodenproduktivität in der Gezira (Sudan)
Authors: Jagnow G. 
Published: February 2007

The influence of irrigation and crop rotation on the humus and nitrogen balance and soil productivity in the Sudan Gezira.Yields of Sorghum and Cotton, but not of Dolichos increased up to 3 times from the 10th to the 30th year in an unfertilized, irrigated field experiment on a vertisol with crop rotations of Cotton, Sorghum and Dolichos, esspecially after preceding years of bare fallow. Nitrogen fixation by root nodules and asymbiotic fixation by Azotobacter and blue green algae are discussed as a cause of the increased soil productivity.In a field pot trial with 2.5 cm layers of flooded soil 75 ppm of nitrogen were fixed in 12 weeks by blue green algae. On fertilization with 0.1% K2HPO4 and 0.1% K2HPO4 + 50 ppm Na2MoO4 they fixed 244 and 290 ppm N respectively. Drying and reflooding the soil once to several times caused the N‐fixation to decrease steadily until it stopped with weekly dryings.Strong increases and decreases of organic C and N were observed in moist and also in dry field soil in different seasons as well as short term fluctuations of organic N in dry field soil.
Phosphatsorption einiger Böden in Bayern
Authors: Schwertmann U. , Knittel H. 
Published: February 2007

Phosphate adsorption of some Bavarian soils.Phosphate adsorption isotherms were established in buffered (pH 4.6, 5.5, 7.0) and some in unbuffered (0.01 M CaCl2) systems for 9 soil profiles, 6 of which represent loess soils in various stages of development. In the P‐equilibrium concentration range of 0–10−4 mole/l two to three ranges can be identified, each of which obeys the Langmuir equation. In the lowest concentration range (0–0.2·10−4 mole/l) adsorption is linearly related to equilibrium concentration. For the different Langmuir ranges the adsorption maxima (b) increase and the adsorption coefficients (k) decrease with increasing equilibrium concentration. The maxima depend on buffer‐pH in the order 5.5<4.6<7.0.A single point method similar to the one recently proposed by Bache and Williams (1971) was succesfully applied to obtain b from a single measurement using a significant correlation between b from complete isotherms and the ratio of P adsorbed to that in solution after the addition of a fixed amount of P (0.8–1,6 mg P/g of soil).The b‐values in the equilibrium concentration range of 1–20·10−4 mole/l depend mainly on soil pH (negative) and clay (positive) (multiple correlation coefficient r = 0.858). The common reason for this appears to be the amount of exchangeable Al which is also significantly correlated with b. During soil development the depth function of b changes due to decalcification, drop of pH and migration of clay and iron oxides.
Ermittlung von Grenzwerten optimaler Kupfer‐Versorgung für Hafer und Sommergerste
Authors: Thiel H. , Finck A. 
Published: February 2007

Determination of limiting values of optimum copper supply of oat and barley plants.In order to determine the copper content required by oat and barley plants (limiting values), pot experiments with increased copper supply as well as plants of high yielding fields were analyzed. Because of the great influence of the nitrogen supply on the Cu‐requirement, the limiting values for Cu should always be related to the range of optimum N‐contents (30–40%o N at the beginning of tillering and 12–20%o at the appearance of the panicle).From the pot experiments the following limiting values in the dry matter of the aerial parts of oats can bei deduced: 5 ppm Cu at the beginning of tillering and 3 ppm at the appearance of the panicle. For (spring sown) barley the corresponding values are 5.5 and 3.5 ppm Cu.The limiting values obtained from the field samples are 4 ppm for oats and 5 ppm für barley (both valid for a yield level of 5 t/ha).In view of their higher yield level, the data of the pot experiments are considered the ‘theoretical’ limiting values.
Der Einfluß der Kaliumkonzentration der ‘Bodenlösung’ auf den Ertrag, den Wasserverbrauch und die K‐Aufnahmearten von Zuckerrüben (Beta vulgaris ssp. esculenta var. altissima)
Authors: Mengel K. , Forster H. 
Published: February 2007

The effect of the potassium concentration of the “soil solution” on the yield, the water consumption and the potassium uptake rates of sugar beets (Beta vulgaris ssp. esculenta var. altissima).1. The object of this experiment was to investigate which K concentration of the nutrient solution can be regarded as optimal for the growth of sugar beets. The nutrient medium was a quartz sand with a nutrient solution, of which the nutrient concentration could be controlled and corrected at any time due to a newly developed technique. Compared with a solution culture this technique enables a contact surface between the roots and the soil solution, which equals more field conditions.2. The experment had three treatments with the following K concentrations: 0.2, 1A and 5.0 me K/1. These K concentrations were controlled and corrected by K additions and were kept approximately constant during the growing period.3. The yields of beet roots and sugar of the treatment “0.2 me K” were significantly lower than the yields of the other two treatments. Although a K concentration of 5.0 me K means a considerable high concentration, the plants of this treatment did not show any depressive effects. Moreover this treatment (5.0 me K) showed the highest yield in beet roots and sugar, which, however, did not differ significantly from the yields of the treatment “1.0 me K”. It is concluded that this K concentration (1.0 me) of the nutrient solution can be regarded as optimal for sugar beet plants. Also under field conditions the order of magnitude of this K concentration in the soil solution may be optimal.4. The daily uptake rates for K were the higher the K concentration of the nutrient solution was. This tendency was particularly obvious in the beginning of the growing period. In each treatments the highest K uptake rates were observed during the maximum leaf growth (2nd half of July).5. High K uptake rates resulted mainly in a considerable increase of the K content of the leaves. But the total cation content (K, Na, Mg, Ca) of the leaves was not affected by these high K uptake rates. In the treatment “0.2 me K” the very low K content of the leaves was compensated quantitatively by higher contents of Ca and Mg. This replacement of K by Ca and Mg, however, could not substitute for the specific functions of K in yield formation.6. The water consumption of the plants related to the weight unit beet roots was the lower the higher the K concentration of the nutrient solution was. Particularly during August and the 1st half of September simultaneously with a higher production of organic material the better K supply resulted in an absolutely lower water consumption.
Effects of temperature, microbial activity, salinity, and pH on the release of nitrogen of sulfur‐coated urea
Authors: Oertli J. J. 
Published: February 2007

Die Wirkung von Temperatur, Mikroorganismenaktivität, Salzgehalt und pH auf die Stickstoff‐Freisetzung von mit Schwefel ummanteltem Harnstoff.Die Wirkung einiger Umweltfaktoren auf die Stickstoffgabe von Schwefel‐umhülltem Harnstoffdünger wurde in Elutionsexperimenten untersucht.Die Nährstoffabgabe nimmt stark zu mit der Temperatur (Q10 ist 5 und höher).Die Abgabe von Harnstoff und dessen Hydrolyse zu Ammoniumionen wird durch Thymol, d.h. durch sterile Bedingungen, stark gehemmt. Impfung mit Thiobacillus thiooxidans fördert die Abgabe bei 34° C, hemmt aber die Hydrolyse des Harnstoffs unter alien Bedingungen.Hohe Eluatkonzentrationen haben relativ wenig Wirkung, und nur eine mäßige Hemmung der weiteren Harnstoffabgabe wird beobachtet. Für die Hydrolyse des Harnstoffs scheint es eine Optimumkonzentration zu geben.Niedrige pH Werte, verursacht durch die Aktivität von Th. thiooxidans gehen parallel mit einer starken Hemmung der Harnstoffhydrolyse und oft mit einer Förderung der Stickstoffabgabe.Aus der Temperaturempfindlichkeit der Stickstoffabgabe wird geschlossen, daß es schwierig sein wird, eine Stickstoffgabe zu bestimmen, die unter allen Bedingungen genügend und dazu auch immer ungiftig ist.
Umwandlung und Verfügbarkeit von Rohphosphat (Hyperphos) verglichen mit aufgeschlossenen Phosphaten unter kontrollierten Temperatur‐ und Feuchtebedingungen
Authors: Scharafat I. , Finck A. 
Published: February 2007

Transformation and availability of rock phosphate (Hyperphos) compared with other fertilizer phosphates under controlled temperature and moisture conditions.In order to characterize the efficient portion of a fertilizer after transformation in soil, in samples of typical soils of Schleswig‐Holstein the easily mobilizable and the mobile P‐content were investigated with specific extractants.The transformation under controlled varied temperature and moisture conditions results first (besides in mobile phosphates) in easily mobilizable Ca‐phosphate. In acid soils this changes gradually into Al‐ and Fe‐phosphate the content of which decreases due to ageing (transformation into hardly mobilizable forms). The pH is the most important factor influencing the kind of transformation whereas high temperature and moisture content mainly increase speed and extent (high temperature accelerating especially the ageing process). The water soluble phosphate is less influenced by temperatur and moisture.The best efficiency of rock phosphates results from rapid transformation (promoted by low pH) into easily mobilizable soil phosphate followed by an ageing‐retarding constellation of factors such as low temperature and moisture.
Zur Entwicklung der Kalium‐Mangelsymptome von Sommerraps
Authors: Pissarek H.‐P. 
Published: February 2007

The development of potassium deficiency symptoms in summer rapeMacroscopic, microscopic and chemical investigations of summer rape plants, grown under glass at different levels of potassium, led to the following results.1. Marginal and intervenal chlorosis of sucessive leaves as well as withering and darkgreen colour can be considered as the early symptoms of potassium deficiency in rape.2. Chlorosis appears often (especially in cases of slight potassium deficiency) first of all in the middle leaves and later in the old leaves.3. With plants, recieving normal amounts of potassium, the highest concentration of potassium is found in the old leaves and the lowest in the young. Only in cases of acute deficiency is this reciprocal.4. The potassium deficiency symptom sequences, given in the literature, appear to be dubious, since the causal relationship, hitherto accepted, between the appearance of collapsed cortical tissue, the enlargement of parenchyma cells and secondary cambium activity does not exist.5. The cambium activity in the stalk with potassium deficiency and so the formation of xylem and phloem is greatly damaged. The formation of structural elements, such as sclerenchyma fibres and woody parenchyma cells, however, is especially affected by this deficiency.6. There are indications that stem necrosis, described as a typical potassium deficiency symptom, is primarily related to parasitic infection favoured by potassium deficiency.
Physiologische Voraussetzungen für die Bildung der Kupfermangelsymptome
Authors: Rahimi A. , Bussler W. 
Published: February 2007

Physiological conditions for the development of copper deficiency symptomsSo as to be able to follow the appearance of copper deficiency symptoms, investigations were initiated to study the time of lignification, transpiration, guard cell mechanism and the growth of epidermis cells.Summarising, it was ascertained that:1) The cause of all typical copper deficiency symptoms, rolling up of the leaves, followed by wilting and death, lies in retarded lignification and incomplete formation of the vascular structure.2) Damaged guard cells must be seen as a late occurring subsequent symptom. This damage appears after the onset of the visible symptoms and still longer after the delay in lignification.3) No relation could be found between the wilting symptoms and the development of epidermis cells.
Potassium release and clay degradation as affected by sodium chloride
Authors: Tahoun S. , Hamdi H. 
Published: February 2007

K‐Abgabe und Tonzersetzung durch NaCl‐Behandlung von S. Tahoun und H. HamdiDer Einfluß von NaCl auf die Kaliumfreisetzung und damit verbundene Veränderungen der Tonminerale einiger alluvialer Böden wurden untersucht. Die Tonfraktion wurde abgetrennt, mit K bzw. Ca gesättigt und anschließend mit 0.5 n NaCl in Intervallen von 12 Stunden 30 Tage behandelt.Aufgrund der Tatsache, daß das vorherrschende Tonmineral Montmorillonit war, wurden beachtliche Mengen Kalium innerhalb weniger Tage ausgetauscht. Mineraleigenes K war sehr resistent gegen die NaCl‐Behandlung. Es kann deshalb angenommen werden, daß die vorliegenden Glimmer Muskovite sind.Die NaCl‐Behandlung bewirkte eine Abnahme der Kristallblattdicke der Tonminerale. Wir schließen daraus, daß ein Bruch an den angewitterten Ecken des Tonmineralgitters aufgetreten ist, so daß kleinere Teilchen sowie amorphe Substanzen entstanden sind.
Die Wirkung von Chlorcholinchlorid (CCC) auf die Ausbildung des Wurzelsystems von Sonnenblumen in Abhängigkeit vom Wassergehalt des Bodens
Authors: Farrahi‐Aschtiani S. , Scharifian S. 
Published: February 2007

The effect of chlorcholinchloride (CCC) on the root formation of sunflower in relation to soil water contentSunflowers were cultivated in pot trials under dry and moist conditions with and without CCC in order to find whether CCC can improve growth under dry conditions. The influence of soil moisture and CCC on the yield and on the anatomy of the roots was investigated. It appears that:1. Growth under dry conditions was improved by the use of CCC2. The stele was much enlarged by CCC which causes a marked increase in root diameter.3. The effect of water deficiency in dry conditions cannot be eliminated by the use of CCC4. The noticeable improvement in root growth under dry conditions after the use of CCC should be investigated further with regard to an improved usage of dry regions.