N-Wirkung von Rindergülle unter Zusatz von Dicyandiamid bzw. Stroh in Gefäß- und Lysimeterversuchen

Utilization of N in cattle slurry after addition of Dicyandiamide resp. straw in pot and lysimeter trials In a pot and lysimeter trial, leaching of nitrate of cattle slurry applied at different times (August, September, October, March) was tested with and without addition of DCD, and utilization of N by the following crop was determined. In a pot trial (sandy silt loam), the effect of additional straw manuring was also investigated. Pots were exposed to natural weather conditions from start of experiment (August) until sowing of rye grass (April). Application of straw as well as addition of DCD to slurry reduced leaching of N considerably. DCD addition with and without straw resulted in significantly higher N removals by rye grass. Unlike ammonium nitrogen “preserved” by DCD, slurry nitrogen biologically fixed by the rotting straw, however, was not yet available to the following rye grass crop (May to July). Slurry + straw + DCD generally led to higher amounts of residue N in the soil as a result of N balance. Also in the lysimeter trial, DCD reduced leaching of nitrate especially in vegetationless periods and thus improved the effect of cattle slurry applied in August resp. November (higher yields and N removals by silage maize).     

Zur Genese der Marschböden. I. Der Einfluß von Sediment- und Bodengefüge

On the genesis of tidal marsh soils I. The influence of sediment- and soil-structure The significance of sediment structure for soil structure has often been disregarded when discussing the properties and genesis of tidal marsh soils. After defening several terms that are often misinterpreted, three types of tidal-marsh-soils with different structure are described: 1 . the typical clayey tidal-marsh-soils with very various aggregate structures: The well aired and permeable “SEEMARSCH” (marine-tidal-marsh-soil) with polyhedral and prismatic structure, which is formed from the flaky “card-house” structure of marine sediments rich on salt; the densely paked “BRACKMARSCH” (brackish-tidal-marsh-soil), whose moisture is due to perched water, which coarse prismatic to columnar structure, which is formed from the mainly horizontally orientet structure of brackish sediments due to dispersion; the moderately permeable “FLUSSMARSCH” (tidal-river-marsh-soil), whose wetness is often due to groundwater, with medium to coarse prismatic structure, which is formed from the finely aggregated structure of perimarine tidal-river sediments; 2 . the tidal marsh soils poor in clay, rich in silt and very fine sand with coherent structure and low air porosity, due to a strong tendency towards puddling of the top soil by raindrops, causes the formation of “HAFTNÄSSEMARSCH” (marsh soil whose moisture is due to capillar water); 3 . the tidal-marsh-soils rich in plant remains, clay and with a high level of groundwater often extremly acid, with coherent structure, which formed the generally highly permeable “ORGANOMARSCH”. The conditions of formation of these soils and the soil parameters are discussed also.     

Auswirkungen von Lockerungsmaßnahmen auf das Bodengefüge von Pseudogleyen

Effect of sub-soiling on the physical characteristics of pseudogleys. . Physical studies on eight soils that had been sub-soiled over a range from two to twelve years before, showed that after two years the loosening of the subsoil was still god. The soils that had been sub-soiled eight to twelve years before were only slightly better than the untreated ones. Available water capacity for plants could not be increased. On the other hand it was possible to decrease mechanical compactness of the soil and to cultivate the soil earlier in the year.     

Einfluß von Meliorationsmaßnahmen auf die kleinräumliche Variation von Waldbodeneigenschaften

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.     

Zur Verwendung von Gesteinsmehlen in der Landwirtschaft. I. Chemisch-mineralogische Zusammensetzung und Eignung von Gesteinsmehlen als Düngemittel

The use of rock powders in agriculture. I. Chemical and mineralogical composition and suitability of rock powders for fertilization Five different rock powders were investigated in order to test their suitability for agricultural fertilization. The fertilization effect of rock powders is greatly influenced by the mineralogical composition and the intensity of grinding, but less by the total content of nutrients. The low content of soluble nutrients (less than 1%) and the high portion of elements without any importance for plant nutrition (more than 70% oxigen-bound Si, Al and Fe) raises the question if rock powders can be successfully applied as fertilizers, at least in annual cropping systems. Because of the enormous differences between the investigated rock powders the term “rock powder” does not describe any specific characteristics for the user.     

Wirkung von Ancymidol auf Längenwachstum und Chlorophyllgehalt von Helianthus annuus L. in Wasserkultur

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.     

Der Einfluß von Gibberellinsäurespritzungen auf das Blühverhalten von Karotten

The influence of Gibberellic Acid Treatments on Flowering of Carrots . The influence of GA₃-treatments on flower formation of carrot plants at different light conditions was investigated. No flower formation occurent during natural long day conditions at all GA₃-concentrations (6, 30, 60 ppm). (Fig. 1). Nevertheless under artificial long day conditions flower formation was observed after application of 30 and 60 ppm GA₃. Apparently a positive interaction between GA₃-application and illumination on shooting exists. Conditions leading to the formation of vegetatives apices from generative are described. (Formation of ‘Hochrosetten’, Fig. 2).     

Atmosphärische Deposition von Bioelementen in Agrarökosysteme 1. Mitteilung: Deposition von Bioelementen mit dem Niederschlag

Atmospheric deposition of bioelements in agrar-ecosystems 1. Report: Deposition of bioelements by precipitation The bioelement deposition by precipitation was measured in 1977–1981 in Göttingen (Niedersachsen). The bioelement concentrations and the deposited quantities are in good agreement with the results of other authors. The mean pH-values of the collected precipitation water in 1980 and '81 in Göttingen was 4,60. The difference to the pH-values measured by Ulrich et al. (1979) in the Solling is explained by the different geographical locations of the ecosystems in connection with the transport of dust and variations in the composition of the soils of the areas. From the view of plant nutrition and soil acidification the contribution of the deposition by precipitation is insignificant for agriculture. Only about 6% of the typical annual Ca-leaching from loamy soils are caused by the H⁺ input by precipitation. The rest is caused by other influences, especially the soil respiration.     

Bestimmung von hydraulischen Parametern für die Wasserhaushaltsuntersuchungen im natürlich gelagerten Boden. Ein Vergleich von Feld- und Laboratoriumsmethoden

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.     

Schätzrahmen zur Beurteilung von Ammoniakverlusten nach Ausbringung von Rinderflüssigmist

Assessment of NH₃ emissions after application of cattle slurry Over a two year period at different sites following application of cattle slurry measurements of NH₃ emissions have been carried out using the Integrated Horizontal Flux Method. The objective of these studies was to quantify NH₃ losses under field conditions and to investigate the influence of various environmental factors on the NH₃ emission. Depending on environmental conditions and infiltration rates NH₃ volatilization losses in the described experiments ranged from 12 to 65 per cent of the applied NH₄-N. Of the many factors influencing NH₃ emission three factors were chosen which can easily be measured or at least estimated. Using these factors a framework for an assessment of NH₃ emissions has been set up. Within this framework the expected NH₃ losses are estimated depending on infiltration rate of the slurry, mean aerial temperature, precipitation and time after application (with or without incorporation of manure). This framework offers a practical tool for evaluation of NH₃ losses after application of cattle slurry and may be used to avoid NH₃ losses under different environmental conditions.     

Einfluß von Sorte und Phosphordüngung auf den Phosphorgehalt und die Aktivität der sauren Phosphatasen von Weizen und Gerste. — Ein Beitrag zur Diagnose der P-Versorgung von Pflanzen —

Influence of cultivar and phosphorus application on P concentration and acid phosphatase activity in wheat and barley. — A contribution to the diagnosis of P supply of plants — Acid phosphatase activity compared to total P concentration was studied as a diagnostic criterion of the phosphorus nutritional status of wheat and barley. In a field experiment with wheat cv ‘Sperber’ the influence of P level on P_ase activity and P concentration was monitored at four developmental stages. Significant correlations with grain yield were found for P_ase activity at all four stages whereas P concentration was significantly correlated with grain yield in the early stage (DC 26–27) only. Genetic variability and influence of P supply on P_ase activity and P concentration was studied at low and at high P supply with 9 wheat and 23 barley cultivars grown for 4 and 5 weeks in pot experiments. The variability of P_ase activity caused by cultivars was higher than that caused by P supply. It is, therefore, concluded that the acid phosphatase activity is not suitable as a generally applicable tool for diagnosing P supply. In comparison, total P concentration of the plants was influenced to a higher degree by P supply than by cultivars. Total P is, therefore, more suitable as a criterion for diagnosing P supply of plants than P_ase activity. The samples, though, have to be collected in stages before DC 27.     

Zur Pedogenese und Klassifikation von Marschböden des Unterweserraumes. II. Die Bedeutung von Schwefelmetabolismus,Methanproduktion und Ca/Mg-Verhältnis für die Marschen-Klassifikation

Development and Classification of Marsh Soils from the Unterweser Region, West Germany. II. Importance of Sulfur Metabolism, Methane Production and Ca/Mg Ratio for Classifying Marsh Soils The importance of sulfur metabolism in each step of marsh soil development (Brümmer, 1968) is also confirmed for the marsh soils of the Unterweser region. Sulfur contents and sulfur fractions indicate that soil development has advanced further in brackish marshes than in marine and river marshes. The results give additional evidence that the various properties of marsh soils are only partly caused by sedimentation conditions. – The sedimentation areas (Müller, 1954) apply only to small regions. Thus, methane production predominates in the freshwater area, while sulfate reduction predominates in the marine area. Both processes occur at high rates in the brackish area. Classifying soils on the basis of the Ca/Mg ratio gives the same soil groups as Brümmers classification. Consequently, classifying the marsh soils of Niedersachsen on the basis of Ca/Mg ratio is a suitable method, if the idea that sedimentation conditions cause soil properties – especially the contents of exchangeable Ca and Mg – and the present designations of the soil groups are rejected.     

Einfluß von N-Lignin auf Wachstum und N-Stoffwechsel von Weizen-Zellsuspensionskulturen

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.     

Dosis- Wirkungs-Beziehungen zur Erfassung von Chemikalienwirkungen auf die mikrobielle Aktivität von Böden: I. Kurvenverläufe und Auswertungsmöglichkeiten

Dose response curves: their use in soil microbiological research and possibilities of evaluation The relation between different concentrations of a toxicant in soils and the resulting effects on biological parameters can be described with dose response curves. Dose response curves make it possible to determine the concentrations of a chemical that create definite effects (?Effective Doses”?, e.g. ED₁₀ and ED₅₀ for 10- and 50% inhibitory effects) or to evaluate the rate of increase of inhibition with increasing concentrations. Some of the mostly used ways to extract these parameters from dose response curves are presented and examined with regard to their suitability in soil microbiological research. Besides graphical procedures for the evaluation of dose response curves a mathematical model for fitting quantitative dose response curves is introduced. With this model the confidence intervals of effective doses can be computed. By showing eight frequently appearing shapes of dose response curves the advantages and limitations of different ways to calculate effective doses are discussed.     

Einfluß von Monoethanolamin auf Ertrag und Wasserausnutzung von Sommergerste

Effect of monoethanolamine on yield and water use efficiency of barley The effect of monoethanolamine (EA) on yield and water use efficiency (WUE) of spring barley plants was tested in pot experiments. The application of EA (8 to 12 mg/pot) increased the grain yield and WUE by about 4 to 15 per cent under stress conditions. In addition, EA improved the utilization of fertilizer nitrogen. The yield-increasing effect of EA was associated with an increase of the number of ear-bearing tillers and an improved root growth. The effects of EA were only significant at α = 0.05.     

N-Wirkung von Rindergülle bzw. Jauche mit Dicyandiamid in Feldversuchen

Utilization of N in cattle slurry and liquid manure with Dicyandiamide in field trials In several field trials on deep loess soils, effects of DCD on utilization of N in cattle slurry and liquid manure by silage maize, sugar beets and turf was tested. DCD inhibited nitrification of NH₄ nitrogen added with slurry or liquid manure and thus decreased losses by infiltration or leaching considerably. If measured as so called “N_min nitrogen” at the start of vegetation, amounts of nitrogen actually present in the soil are underrated in plots with slurry or liquid manure + DCD. Addition of DCD at a rate of 30 kg/ha to slurry and 15–30 kg to liquid manure improved in all cases utilization of N in slurry applied in April or between August and November and of liquid manure applied in November. By use of the nitrification inhibitor Dicyandiamide as complement to slurry or liquid manure it is therefore possible to inhibit decomposition of ammonium nitrogen in these organic manures for 2–4 months depending on temperature, and to “preserve” it during periods without vegetation when soils are especially exposed to leaching. By this means, utilization of slurry-nitrogen by the following crop can be improved considerably.