bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relevance of soil N mineralization, total N demand of crops and efficiency of applied N for fertilizer recommendations for cereals — Theory and application
Authors: Appel Thomas 
Published: February 2007

AbstractOptimal rates of N fertilizer depend mainly on three factors, (1) the total N demand of crops, (2) the amount of available N from sources other than applied N, and (3) the efficiency of fertilization in order to increase plant available N. Predictability and variability of each of these factors affect the precision of N fertilizer recommendations.In a theoretical approach the change of [crop N + extractable inorganic soil N] (CSN) in N‐fertilized cereals can be ascribed to two components, firstly an N rate independent and secondly a strongly N rate dependent one. This approach fits well when applied to an actual data set of N field trials on sandy soils in Hessia, Germany.The N rate dependent change of CSN was interpreted as apparent recovery of applied N indicating the efficiency of fertilization. Apparent recovery rates of applied N varied considerably between field sites and ranged from 33 % to 96 %.The N rate independent change of CSN was dominated by N mineralization, especially during the grain filling period (range: 4 to 61 kg N ha−1), and was significantly (p <0.001) correlated with extractable soil organic N (r = 0.65, CaCl2 extraction; r = 0.51, EUF‐technique).The total N demand of the crops varied widely within each cereal species. For barley and rye the total N demand was closely correlated with the optimal grain yield.The results suggest that in order to improve N fertilizer recommendations the prediction of the total N demand as well as the prediction of the fertilizer efficiency is badly needed. The soil N mineralization appeared to be an important N source for cereals, which was independent from the applied N rate. Soil N tests, which provide an index of mineralizable soil N, merit therefore consideration for adoption into N fertilizer recommendations for cereals.
Evaluation of Some Chelates in Estimating Available Zn for Soybean in Calcareous Soils
Authors: Al‐Mustafa W. A. , Modaihsh A. S. , Abdallah A. E. , El‐Shall A. A. 
Published: February 2007

AbstractSix fertilizer trials on calcareous soils in Saudi Arabia were conducted for the prediction of Zn deficiency in soybean (Glycine max L., var Merr). Zinc level before planting was tested by using 3 different extractants, i.e. DTPA, AB‐DTPA and EDTA. Zinc was applied in the form of ZnSO4 · 7H2O at 0, 5, 10, 15, 20 and 40 kg Zn ha−1. Plant samples were taken at early bloom and tissue was analysed for Zn. Two methods were used to judge the critical deficiency level of Zn: Cate‐Nelson and chisquare models.The critical level estimated according to the Cate‐Nelson method for DTPA extractable soil Zn was 0.43 mg kg−1 in the growing season 1991. EDTA gave a much higher level (1.80 mg kg−1) and AB‐DTPA gave an intermediate level (0.68 mg kg−1). Chi‐square statistical procedure gave a very similar critical level of 0.66 mg kg−1 for AB‐DTPA but lower for either DTPA (0.38 mg kg−1) or EDTA (1.32 mg kg−1). The critical level based for three growing seasons ranged from 0.25 to 0.68, 0.32 to 0.82 and 1.12 to 3.4 mg Zn kg−1 for DTPA, AB‐DTPA and EDTA extractants, respectively.The values obtained by the linear regression equation with soybean leaf concentration were 0.45 and 0.70 mg Zn kg−1 for DTPA and AB‐DTPA, respectively. Such values are very close to those determined by using the Cate‐Nelson method. On the other hand, the value obtained for EDTA (1.15 mg Zn kg−1) was comparatively lower than that calculated by applying the Cate‐Nelson method.
Einfluß des Jahresniederschlags und der Bodenart auf die 137Cs‐Tiefenverteilung in Böden Südchiles
Authors: Schuller Paulina , Ellies Achim 
Published: February 2007

AbstractUntersucht wurde der Einfluß des Jahresniederschlags und der Bodenart auf die Langzeit‐Tiefenverteilung vom globalen Fallout‐137Cs in ungestörten südchilenischen Böden vulkanischer Herkunft. Die Flächenaktivität und die Eindringtiefe nehmen mit dem mittleren Jahresniederschlag zu. Trotz der hohen Regenmenge (970 – 2500 mm a−1) befindet sich der größte Anteil des 137Cs in den ersten 10 cm Bodentiefe. Die vertikale Ausbreitung wird einerseits durch die hohe Adsorptionskapazität der Vulkanascheböden vermindert, andererseits jedoch wird sie in Böden mit einem hohen Grobporenraum zum Teil gefördert. Die Eindringtiefe erreicht in den untersuchten Tonböden nur bis zu 26 cm, in den Schluffböden bis 35 cm und im Sandboden 70 cm Tiefe.
Wirkungen technogener Druckbelastung auf die Spannungsverteilung und das Bodengefüge einer Schwarzerde aus Löß
Authors: Horn Rainer , Werner Dietrich , Baumgartl Thomas , Winterot Christel 
Published: February 2007

AbstractIm Rahmen der Untersuchungen zur Frage nach dem Einfluß der Befahrungshäufigkeit auf die Gefügeentwicklung und Änderung der ökologischen Funktionen in einer Schwarzerde aus Löß wurden bodenmechanische Spannungs‐ und Stabilitätsmessungen sowie röntgenmorphologische Untersuchungen durchgeführt. Es konnte nachgewiesen werden, daß die Spannungskomponenten (orthogonale Scherspannungen und mittlere Normalspannungen ebenso wie die einzelnen Hauptspannungskomponenten) u.a. mit der Häufigkeit der Befahrung variieren. Bei hohem Wassergehalt und oberhalb der Mohr Coulomb Linie liegende Werte für die oktahedrische Scherspannung bei gegebener mittlerer Normalspannung ist damit der Vorgang der knetenden und damit homogenisierenden Verformung als nachhaltig gefügezerstörend zu berücksichtigen. Anhand von Röntgennegativbildauswertungen konnte der Prozeß der Dichtpackung von Aggregaten bzw. der Homogenisierung durch Zerknetung in Gegenwart von leicht beweglichem d.h. schwach gebundenem oder selbst unter Überdruck stehendem Wasser nachgewiesen werden. Die Auswirkungen auf Wasser‐ und Luftleitfähigkeit werden diskutiert.
Aluminium Tolerance of Maize Cultivars as Assessed by Callose Production and Root Elongation
Authors: Llugany Mercé , Massot Nuria , Wissemeier Alexander H. , Poschenrieder Charlotte , Horst Walter J. , Barceló Juan 
Published: February 2007

AbstractThe differences in Al tolerance between 12 maize cultivars were investigated using early stress indicators such as relative root elongation rate, induction of callose formation and Al concentrations in 5 mm root tips. Plants were grown in nutrient solution (pH 4.3) and exposed to 0 (control), 20 or 50 μM Al for 24 h. According to the relative root elongation rates, Regent, C 525 M and Adour 250 were the most Al‐tolerant cultivars, while BR 201 F, Teosinte, Alarik, Burras and HS 7777 were Al‐sensitive. Cultivars Brummi, HS 1230, Lixis and Aladin showed an intermediate behaviour. A significant inverse correlation between relative root‐elongation rates and both Al concentration in root tips and callose concentrations could be established. The usefulness of callose as an early indicator of Al stress and the importance of Al exclusion from root tips as an Al tolerance mechanism are discussed.
Potassium replenishment capacity of illitic soils at their minimal exchangeable K in relation to clay mineralogy
Authors: Rao Ch. Srinivasa , Khera M. S. 
Published: February 2007

AbstractPotassium replenishment capacity of eight soil series with varying illite content of their clay fraction were studied at their minimal exchangeable K through green house experiments. Higher minimal K levels were found in soils with high initial K status. Maximum K uptake values were associated with high minimal K. The % illite also had a significant relationship with minimum K levels. Average daily rates of K replenishment of soils varied between 0.25 and 0.67 mg kg−1 soil after reaching minimum K. The K replenishment rates were found highly correlated with minimal exchangeable K (0.96**). Amount of clay failed to attain the level of significance with K replenishment rate. Soils with higher illite content in their clay showed high K replenishment rates.
Effects of meliorative additives on the adsorption and binding forms of heavy metals in a contaminated topsoil from a former sewage farm
Authors: Marschner Bernd , Henke Uta , Wessolek Gerd 
Published: February 2007

AbstractIn a laboratory study, a heavy metal contaminated topsoil from a former sewage farm in Berlin was amended with different additives: lime, ash/gypsum, bark mulch, brown coal and combinations of these treatments. After 8 weeks of incubation, pH of the lime and ash/gypsum treatments increased to 6.2–6.3 compared to 5.2–5.3 in the control and the other treatments. Organic‐C content rose from 42 g/kg in the control to 46–53 g/kg in the organic amendments. In reaction to the pH‐increase the water soluble fraction of Cd, Cu and Zn was reduced by roughly 60%, 30% and 80% respectively. Cd‐ and Zn‐binding forms as determined with NH4‐acetate‐ and EDTA‐extracts were not affected by the treatments, while the ash/gypsum‐treatment increased EDTA‐extractable Pb by 17%. The exchangeable Cu‐Fraction (NH4‐acetate extract) was reduced in all treatments to 82–93% of the control values, with the greatest effects in the tree bark amendment. The FREUNDLICH adsorption isotherms also show an increased sorption of heavy metals in the lime and ash/gypsum treatments. Organic amendments alone or in combination with lime had little effect on heavy metal adsorption.
Soil Surface Roughness as the Result of Aggregate Size Distribution 1. Report: Measuring and Evaluation Method
Authors: Frede Hans‐Georg , Gäth Stefan 
Published: February 2007

AbstractIt is assumed that the soil surface roughness is related to single aggregate size classes and the evaluation procedure was developed. If is based on the high resolution measurements with a noncontact laser scanner. Single harmonic ozcillations corresponding to aggregate size classes are filtered out from the surface profile using the Fourier analysis. By means of two examples, the advantage of this method over the simple profile length ratio is demonstrated.
Soil Surface Roughness as the Result of Aggregate Size Distribution 2. Report: Change in aggregate size classes caused by erosive rainfalls
Authors: Gäth Stefan , Görk Heike , Frede Hans‐Georg 
Published: February 2007

AbstractThe change of aggregate size classes caused by rainfall was examined using six different silly soils. The surface elevation profile lines were measured with a non‐contact laser scanner with a measurement resolution of O.1 mm. The profile length ratio RZ and, based on the Fourier‐analysis of the elevation profile line, the partial roughness were determined.The results demonstrate that in contrast to the profile length ratio RZ, the evaluation of partial roughness is an adequate method to determine the proportion of aggregate size fractions on total surface roughness. Furthermore, the results show that — independent of the soil texture and history — the smallest aggregate size classes are the most labile fractions. These small and labile aggregate size fractions are involved in the soil erosion process, especially in surface sealing. The extent of surface sealing, however, is influenced by soil texture, too.
Cellular and subcellular compartmentation of sulphate in leaves in relation to low sulphur mobility
Authors: Bell Chris , Fordham Mike , Richardson Paul , Cram John , Tomos Deri 
Published: February 2007

AbstractTracer kinetics and single cell sampling both suggest that S is compartmented differently in vacuoles of epidermal and mesophyll cells. Cytoplasmic S turns over rapidly, but vacuolar turnover in both cell types is too slow to support plant growth, thus accounting in part for the apparent low mobility of S in mature leaves.
Influence of abiotic stress on the GSH/GSSG system of plant cell cultures
Authors: Tepe Monika , Harms Hans 
Published: February 2007

AbstractCell suspension cultures of various crop plants have been used for studying salt and drought stress on the GSH/GSSG‐system, As already recorded for whole plants, cell cultures of different species vary in their glutathione levels. In general, cell cultures of species with relatively high glutathione content are more tolerant to abiotic stress. A high glutathione content alone is not adequate to prevent cell damage and a decrease in cell growth. E.g. the addition of sulphur to stressed cell cultures slightly enhances the GSH content but does not enhance the adaptation of these cells to stress. Thus, the role of glutathione in the adaptation of cells to stress situations seems to be only one component in a more complex response mechanism.
Enhanced sensitivity of a glutathione‐deficient yeast strain to thiram and dimethyldithiocarbamic acid
Authors: Elskens Marc, T. , Penninckx Michel, J. 
Published: February 2007

AbstractThe sensitivity of a glutathione‐deficient mutant of yeast towards thiram and dimethyl dithiocarbamic acid was compared to that of a wild strain. It was shown that the GSH contents of the cell correlated with the toxicity of both drugs, and that glutathione is probably involved in the metabolism of these drugs.
The effect of foliar applied sulphur on individual glucosinolates in oilseed rape seed
Authors: Booth Elaine J. , Batchelor Sheila E. , Walker Kerr C. 
Published: February 2007

AbstractThe effect of foliar applied elemental sulphur on the individual glucosinolate content of oilseed rape seed was studied. Results show that the proportions of individual glucosinolates remained stable despite changes in the amount of sulphur applied, indicating that controlling sulphur availability cannot be used as a management tool to reduce the toxicity of rapeseed meal.
Sulphur amino acid content and nutritive value of pea and cauliflower crude protein as influenced by Sulphur deficiency
Authors: Eppendorfer Wilfried H. , Eggum Bjørn O. 
Published: February 2007

AbstractCystine concentrations (g/16g N) in plant tissue declined more under S deficiency conditions than methionine. In N‐balance trials with rats the negative effect of S deficiency on S amino acid composition of peas and cauliflower resulted in a corresponding decrease of the biological value of the protein.
Sulphur deficiency in oilseed rape and cereals ‐ Experience from Swedish field trials
Authors: Kjellquist Tomas , Gruvaeus Ingemar 
Published: February 2007

AbstractField trials in Sweden have shown responses to S‐fertilizers by rapeseed, but not by barley. These responses varied from 0 to approximately 200 kg/ha seed. They are, however, hard to predict and the criteria of S availability have to be elucidated.
Evaluation of the sulphur status of some soils from Portugal
Authors: Serrão Maria Da Graça , Syers John Keith 
Published: February 2007

AbstractTotal S, extractable SO4, and SO4− retention capacity were determined in a range of soils covering the dominant soil groups in Portugal which are expected to show S deficiency. Total S was relatively low (83–435 mg S kg−1) in all soils and KH2PO4− extractable SO4 was, in general, low for plant growth, ranging from 0.9 to 32.2 mg S kg−1. SO4− retention capacity ranged from −33.1 to 64.7 mg S kg−1 and was negative in many (14 out of 20) of the soils. Most of the soils are expected to be S deficient and show extensive leaching of SO4. Other selected soil properties that may affect the chemistry of SO4 were determined. A highly significant simple correlation was obtained between SO4 adsorbed and extractable Al by the Mehra and Jackson method (CDB‐Al) (r = 0.74; P < 0.001). A multiple regression which included silt improved the correlation of SO4 adsorbed with CDB‐Al (r = 0.79; P < 0.001).
Forms and plant‐availability of sulfur in cattle and pig slurry
Authors: Eriksen Jørgen , Mortensen Jørgen V. , Kjellerup Viggo K. , Kristjansen Ole 
Published: February 2007

AbstractThe contribution of animal slurry to the supply of S to plants was studied. The total‐S content of cattle and pig slurry was significantly correlated to DM and nitrogen content and was composed of sulfide, sulfate and C‐bonded S. During 42 weeks of storage sulfate concentrations decreased and sulfide and C‐bonded S concentrations increased. In a pot experiment plant‐availability of S in slurry was found to be low, 5 to 7% of total‐S.
Bodennutzung und Nitrat‐Stickstoff in der Dränzone von Lößdecken der südlichen Niederrheinischen Bucht
Authors: Henscheid Stefan , Zepp Harald 
Published: February 2007

AbstractMittlere langjährige Stickstoffausträge an 7 Standorten mit Getreide‐Hackfrucht‐Fruchtfolgen werden bestimmt. Die Quantifizierung erfolgt durch die Kombination von Bodenwasserhaushalts‐Simulationsmodellen mit den in der Dränzone unterhalb des Wurzelraums erbohrten Stickstoffgehalten. Bei den mineralisch gedüngten Flächen werden im Mittel 11‐18 und bei den zusätzlich organisch gedüngten 30‐36 kg NO3− N/ha · a ausgetragen.
Morphogenesis and erodibility of soil‐saprolite complexes from magmatic rocks in Swaziland (Southern Africa)
Authors: Scholten Thomas , Felix‐Henningsen Peter , Mushala Hezekiel M. 
Published: February 2007

AbstractThe Kingdom of Swaziland in Southern Africa is affected by diverse forms of severe soil erosion as a consequence of population growth, deforestation, and overgrazing of the grass savanna. The physical, chemical and mineralogical properties of soil‐saprolite complexes show that the presence of relict saprolite underlying the soils is an essential precondition for the development and rapid expansion of deep incising erosion gullies in areas with magmatic rocks. The polygenetic isovolumetric weathering of saprolite led to mass losses of more than 50 vol.‐% due to the formation of solution cavities by leaching in warm and humid climatic phases. Therefore, the saprolite is highly susceptible to erosion. Low structure stability of the saprolite, indicated by shear strength values < 5 kPa, results from a silty texture, absence of organic matter, and low contents of Fe‐ and Al‐oxides and exchangeable Al‐ions. On the contrary, the clay‐rich ferrallitic soils developed from saprolite are comparatively stable against erosion. The relatively high structure stability of the soil, indicated by shear strength values ranging from 7 to 12 kPa, results from the organic matter content of about 3 wt.‐% Corg in the topsoil, up to 7 wt.‐% pedogenic Fe‐ and Al‐oxides, pH(KCI)‐values around 4, and Al‐saturations above 50 %.Concerning the genesis and the susceptibility to erosion, the results show a distinct bipartition of the weathering mantle. Therefore, it is necessary to investigate the site properties and spatial distribution of complete soil‐saprolite complexes from magmatic rocks as a basis of soil erosion control, land evaluation, and land use planning.
Zur Darstellung von Schichtwechseln in periglazialen Decklagen des Bayerischen Waldes unter besonderer Berücksichtigung der Mittellage und ihrer Eigenschaften
Authors: Völkel Jörg 
Published: February 2007

AbstractEs werden Methoden diskutiert, die geeignet erscheinen, die Gliederung periglazialer Decklagen und ihre stoffliche Beschaffenheit über den Feldbefund hinaus zu präzisieren. Untersuchungsgebiet ist der Bayerische Wald und angrenzende Gebiete. Wichtige Informationen hinsichtlich Schichtwechseln und Materialbeschaffenheit gibt bereits die Kornverteilung. Eine weitere rechnerische Abstraktion dieser Daten im Sinne von Schichtungskoeffizienten gelingt aus methodischen Gründen jedoch nicht. Schwermineralspektren trennen die äolisch beeinflußten Lagen von lößfreien Schichtgliedern und zeigen Materialverwandtschaft auf. Darüberhinaus charakterisieren sie den Verwitterungsgrad sowohl der periglazialen Deckschichten als auch des anstehenden Gesteins. Das Laacher See‐Spektrum als Zeitmarke fehlt im Untersuchungsgebiet. Haupt‐ und Spurenelemente des Feinbodens weisen ebenfalls sehr sensibel Materialwechsel nach. Untersuchungen an pedogenen Oxiden unterschiedlicher Fraktionen lassen vermuten, daß das Substrat der periglazialen Deckschichten bereits präsedimentär pedogen überprägt wurde. Das gilt insbesondere für die Mittellage, deren Ansprache und Genese im Vordergrund des Beitrages steht. Röntgendiffraktometrische Untersuchungen an der Tonfraktion dienen der Trennung von pedogenen Transformationen und Sedimenteigenschaften und belegen umfangreichen äolischen Eintrag an Schluff und Ton in die Haupt‐ und Mittellagen. Die Merkmalcharakteristik der einzelnen Schichtglieder wird vorgestellt und die Besonderheiten der Mittellage sowie Abweichungen von den in der Literatur angegebenen Kriterien diskutiert.
DELPHI ‐ Ein Modell zur Langzeitprognose der Verlagerung von Stoffen in Böden
Authors: Hennig Achim 
Published: February 2007

AbstractEs wird ein neues Computermodell zum Verhalten von Stoffen in Böden vorgestellt, dessen Anwendung speziell für Langzeitsimulationen sinnvoll ist. Es unterscheidet sich von anderen Modellen durch

• die Integration eines Kaskadenmodells zur Beschreibung der Wasserbewegung im Boden

• die bodentemperaturabhängige Erfassung monatstypischer Umsetzungsraten

• eine iterative Lösung der Konvektions‐Dispersionsgleichung sowie

• die Möglichkeit, räumlich variable Porenwassergeschwindigkeiten zu berücksichtigen.
Jahreszeitliche Schwefeldynamik semisubhydrischer Salzmarschen
Authors: Bloem Elke , Lüttmann Birgit , Giani Luise 
Published: February 2007

AbstractUntersucht wurde die jahreszeitliche Schwefeldynamik semisubhydrischer Salzmarschen des Neuwarpeler‐Außengrodens (südliche Nordseeküste) von August 1991 bis Oktober 1992. Zur Erfassung der Schwefeldynamik wurde eine fraktionierte Analyse von Schwefel vorgenommen: der Gesamtschwefel (HNO3/HCI‐Aufschluß), der Sulfid‐Schwefel (HCI‐Aufschluß) und der Sulfat‐Schwefel (MgCl2− Extraktion) wurden bestimmt, sowie der organische Schwefel und der Pyrit‐Schwefel errechnet. Die dominierende Schwefelfraktion war Pyrit, gefolgt vom organischen Schwefel, Sulfat und Sulfid. Die Sulfidgehalte veränderten sich nicht wesentlich im Jahresverlauf. Die Sulfatgehalte waren im Sommer am höchsten und im Winter am niedrigsten. Sie waren positiv mit den Chloridgehalten korreliert. Die Gesamtschwefelgehalte waren im Sommer und Winter am höchsten. Sie kennzeichnen eine Zweiphasigkeit der Pyritbildung. Die Redoxpotentiale zeigen, daß im Sommer gleichzeitig mit der Sulfatreduktion und Pyritbildung Reoxidationsprozesse stattfanden.
Zur hydrologischen Bedeutung der organischen Auflage im Wald: Untersuchungsmethoden und erste Ergebnisse
Authors: Thamm Frank , Widmoser Peter 
Published: February 2007

AbstractDas Kompartiment Auflagehumus stellt einen Interzeptionsspeicher für den Kronendurchlaß von Waldökosystemen dar und muß in detaillierten forsthydrologischen Bilanzierungen explizit berücksichtigt werden.In der vorliegenden Arbeit wird die innerhalb des FE‐Vorhabens Ökosystemforschung im Bereich der Bornhöveder Seenkette zur Bestimmung des Mineralbodeninputs (Humussickerung) entwickelte Sammel‐ und Meßtechnik vorgestellt.Neben den eigentlichen Geräten zur Gewinnung der genannten Kompartimentsickerung (Saugplatten und Streulysimeter) werden die Techniken zur kontinuierlichen Erfassung der Flüsse bzw. zur wasserspannungsabhängigen Unterdruckführung beschrieben. Das System zur Sickerwasserregistrierung erbringt eine Auflösung von ca. 0,1 mm. Verschiedene Grafiken illustrieren die Instrumentierung resp. die gemessenen Rohdaten sowie einige beispielhafte Ergebnisse. Darüber hinaus werden die verwendeten. Materialien sowie deren Eigenschaften und Bezugsquellen genannt.