Kaliumwirkung verschiedener Güllen

Potassium effect of different liquid manures In a pot trial on loamy sand (pH 7.0) the solubility and effect of potassium of cattle, pig, and poultry liquid manure was tested with rye grass (Lolium perenne). Potassium of liquid manure is 83–90% soluble in water and up to 100% in calcium chloride. Independent of its origin (animal species) potassium shows a largely similar effect to potassium chloride. Solely potassium from poultry liquid manure was released at a somewhat slower rate. To assess K-requirements in a crop rotation, liquid manure-K can be assumed equal to K of mineral fertilizers.     

Der Einfluß von Cadmium im Boden auf den Ertrag verschiedener Pflanzenarten und deren Cadmiumgehalt

Influence of Cadmium in Soil on the Yield of Various Plant Species and their Cadmium Content In pot experiments the influence of increasing quantities of cadmium in the soil (< 250 mg Cd/kg) on the growth of carrot, bushbean, tomato, ray grass and the cadmium content of various plant parts were studied. Considerable differences of the various plant species are observed. Sensitivity increases in the order: tomato (low) < broccoli < oat < lettuce < ray grass = carrot root < radish < bushbean = pea < spinach (very sensitive). Symptoms of toxicity are found in bush beans only. Fruit, seeds and roots accumulate less cadmium then leaves and straw.     

Die Wirkung verschiedener im Frühjahr und Herbst durchgeführter Bodenbearbeitungsmethoden auf lehmigem Sand

Es werden die Kaliumbilanzen von 6 unterschiedlichen hydromorphen Mineralböden mitgeteilt. Die Untersuchungszeit betrug 13 bis 19 Jahre. Die Lysimeterböden wurden im intensiven Futterbau genutzt. Obwohl die jährliche K‐Düngung im Mittel 18...19 g.m‐²(180...190 kg.ha^?1) betrug, ist bei allen Böden die Bilanz negativ. Der mittlere jährliche K‐Verlust aus dem System Boden schwankt zwischen 5,5 und 21,6 g.m^?2(55...216 kg.ha^?1)· Den höchsten Verlust erlitt ein Sand‐Humusgley, den geringsten ein Tieflehm‐Humusamphigley. Der engste Zusammenhang ergab sich zwischen absolutem K‐Vorrat und dem K‐Verlust.     

Zur nitrifikationshemmenden Wirkung von Dicyandiamid zu Gülle in der Zeit zwischen Spätherbst und Frühjahr

Effect of dicyandiamide on the nitrification of liquid manure between late autumn and spring The influence of soil temperature on the nitrification of slurry manure with and without addition of the nitrification inhibitor dicyandiamide and the decomposition of dicyandiamide was tested in model experiments. 1. NH₄-N of cattle slurry was completely nitrified within 10 or 30 weeks at 4°C or 0°C respectively in a growth chamber. The addition of dicyandiamide retarded the formation of NO₃ in the first case for about 15 weeks (dicyandiamide was completely decomposed after 25 weeks), in the latter case for more than 30 weeks. 2. A simulation of field soil temperatures from October till May in an incubation trial resulted in full nitrification within four weeks, with dicyandiamide within 30 weeks. 3. Slurry mixed with soil, burried in polyethylene-bottles into the top soil of the open field, was nitrified until February when applied at the beginning of November, or until April when applied at the beginning of March. With DCD-addition, however, only one fourth of March-Slurry or hardly half of November-Slurry was nitrified. At the same time, in each case about 30% of the applied amount of DCD was still detectable.     

Das Verhalten von Bleitetraalkylen im Boden und deren Aufnahme durch die Pflanze

The behaviour of leadtetraalkyls in the soil and their uptake by plants In pot experiments the behaviour of the leadtetraalkyls leadtetramethyl and leadtetraethyl in soil and their uptake by spring wheat was investigated. In the soil the leadtetraalkyls were converted quickly to water soluble lead compounds, which showed a high plant toxicity and plant availability. Consequently there was a relatively large lead enrichment in the vegetative and generative plant parts. At higher concentration also a yield depression occured. Comparable amounts of lead in the form of an inorganic salt did not result in Pb-accumulation in plants. From the continuous uptake of lead, which was observed over a period of 3 months, it is concluded, that leadtetraalkyls were decomposed to Pb²⁺ slowly and the Pb-fixation was correspondingly slow. The soluble lead compounds resulting from the leadtetraalkyls could be leached out easily from soil by water. There was a close relation between the level of leadtetraalkyl applied and the waterextractable lead. Moreover it is demonstrated, that plants, which have taken up only inorganic lead salts, are capable to synthesize lead compounds soluble in unpolar organic solvents even in cases in which the soils did not contain leadtetraalkyls.     

Chemische Eigenschaften von Waldböden im Nordwestdeutschen Pleistocän und deren Gruppierungen nach Pufferbereichen

Chemical properties of forest soils in the pleistocene of Northwest Germany and their classification based on soil buffering systems In order to characterize the chemical characteristics of forest soils of Hamburg, 800 soil samples and 400 root samples from 172 sites were used to obtain suitable soil chemical and ecochemical parameters. A strong and deep reaching soil acidification was observed on all sites with exception of those on till. The sulfate concentration in the equilibrium soil solution allows the conclusion that deposition of acid plays a significant role in this acidification. Classification of sites based on edaphic factors did not provide useful information on the chemical status of soils. However, grouping of soil horizons using pH measured in 0.01 M CaCl₂ lead to a stratification according to the soil buffering systems. Distinction between the exchanger and the aluminium buffer ranges was, however, not quite satisfactory.     

Überleben inokulierter Rhizosphärenbakterien und deren Einfluß auf native Bakterienpopulationen im Wurzelraum von Luzerne

Survival of inoculated rhizosphere bacteria and their influence on native bacterial populations in the rhizosphere of alfalfa The survival of inoculated bacteria and their influence on native bacterial populations in the rhizosphere of alfalfa were investigated in a greenhouse experiment. The plant growth promoting strains Rhizobium meliloti me18 and Pseudomonas fluorescens PsIA12 were reisolated from the rhizosphere about 7 weeks after single and mixed strain inoculation. They did not induce lasting changes in the diversity of the native bacterial communities of the rhizosphere. Only within the first week after inoculation was an increase in total bacterial abundance observed. In general, the diversity of bacterial communities increased with plant age and with proximity to the root tip.     

Ertragsbildung,Bestandesaufbau und Stickstoffverwertung von Winterweizen bei kombinierter Gülle- und Mineraldüngung

Effect of combined slurry and mineral fertilization on yield formation, yield components and nitrogen efficiency of winter wheat From 1984/85 to 1987/88 field trials were conducted on the experimental farm Roggenstein in order to examine the efficiency of pig slurry applied at different developmental stages of winter wheat combined with different dosage and distributions of mineral N-fertilizer. On the average over 4 years, maximum grain yield by applying exclusively mineral N-fertilizer has been achieved with 120 kg N/ha, with the optimal amount of N-fertilizer at the 3 developmental stages being 40 kg N/ha, respectively. Decreased yields induced by a reduced mineral N-fertilization could be compensated by application of 20 m³/ha or 40 m³/ha slurry either at the beginning of the growing period, EC 30-31 or EC 33-35 developmental stages. However, mineral fertilizer equivalents calculated on the basis of the NH₄^? N-content of slurries for each year ranged from 25 to 79 in dependence of application date and prevailing weather conditions. Regarding the effect on yield components, no difference between slurry and mineral N-fertilizer were observed. The mediocre and very variable efficiency of slurry-N leads to the conclusion, that the use of slurry in cereal production may be of limited value for agronomic as well as for ecological reasons, as long as no efficient and cost-effective application techniques are available.     

Abbau und biozide Wirkung von Pflanzenschutz-und Schädlingsbekämpfungsmitteln im Boden am Beispiel von Kelevan

Degradation and biocide effect of chemical plant protecting agents and pesticides in soils by the example of the insecticide Kelevan By the example of the insecticide Kelevan it is proved that by means of a combined test plan degradation and biocide effect of chemical plant protecting agents and pesticides in soils can be tested simultaneously. For this test two different test soils as described in leaflet No. 36 of the Biologische Bundesanstalt (BBA), Braunschweig, are each divided in test samples of about 200 g dry matter. To answer the question whether besides the biotic an abiotic degradation of Kelevan and its primary subsequent products takes place in top soil, too, one part of the soil samples was sterilized by overheated steam. Afterwards these and the non-sterilized soil samples were treated with known amounts of Kelevan[cage-U-¹⁴C] and in accordance to leaflet No. 36 of the BBA stored in the dark at 22°U65% r. h. or under field conditions for different periods. To investigate the effect of Kelevan and its metabolites on microorganisms in top soil, further soil samples were treated with increasing amounts of Kelevan and also stored for different periods. At the end of storage periods on an average W,2 % of applicated radioactivities were recovered in the soil samples with Kelevan[cage-U-¹⁴C]. Whereas readioactivities of sterilized soil samples were nearly quantitatively extractable, increasing radioactivity amounts were held back under the same extraction conditions by the native soil samples, which were present as organic residue components of Kelevan(cagc-U-¹⁴C) and not as ¹⁴C-containing carbonate. During degradation, in both test soils as well under laboratory conditions as under field conditions, about one third of Kelevan[cage-U-¹⁴C] was transferred within 30 months via Kelevan acid[cage-U-¹⁴C] to Chlordecon[cage-U-¹⁴C] and about two thirds were transferred into various unknown ¹⁴C-labelled degradation products. The results of microbiological investigation prove that microorganisms were evidently neither selected nor decimated in both test soils by Kelevan and its degradation products.     

Untersuchungen über die toxische Wirkung der in Siedlungsabfällen häufigen Schwermetalle auf die Bodenmikroflora

The toxic effects of heavy metals, commonly found in urban wastes on the soil microflora In several series the influence of soluble salts of Cd, Cr, Zn, Cu, Ni and Hg in various concentrations was tested on the development of bacteria and fungi in cultural studies and in soil model systems. In addition the changes in microbial biomass, in the activity of oxidoreductases and hydrolases, and in nitrification were measured in five soils. Comparison of the results of bacteria-plate-counts in the presence of heavy metals in agar-media and in soils demonstrated that all tested elements have a more toxic effect on isolated soil microorganisms under culture conditions than when tested after heavy metal application to soils. Beside Hg, eucaryotic soil fungi proved to be 10 – 50 fold more resistant to heavy metals in vitro as well as in situ. For calculating the effect of heavy metals on soil microbial activity soil enzymatic methods are not reliable and can be used only to some extent, because some cellfree encymes in the soil are activated or inactivated immediately by heavy metals. In long-term experiments, the microbial biomass and nitrification in soil is not significantly influenced by the elements Cd, Cu and Ni in the concentration range of the tolerable limit content. In contrast, Cr, Zn and Hg reduced these microbiological properties more or less distinctly.     

Sephadex-Gelfiltration von Huminsäuren und deren Gehalt an Aminosäuren

Gel filtration on Sephadex of humic acids and their content of amino acids

• 1 Brown humic substances from the A_h of an iron-humus podzol were separated on Sephadex G 25 into three fractions. The first fraction (Ve/Vo = 1.0–1.5) has the lowest value of Q 4/6 (5.0–8.0), the second the highest Q 4/6 (10.0–12.0) and the third a middle one (8.0–10.5). The adsorption effect may take place during separation.
• 2 The asymmetric form of the integral elution curves of the first fraction indicated that the humic substances are a set of particles with different size. The separation is influenced by diffusion into the pores of gel matrix.
• 3 In the first fraction were determined 16, in the second 13 and in the third 10 amino acids.
• 4 The titration curves of the first fraction (after separation on G 25) indicated that the rate of pH change with alkali added becomes its maximum at pH 6.5–7.5 at different ionic strengths.
• 5 Dialysed humic acids (H⁺ form) were fractionated on G 75. The alkali consumption up to pH 7.5 in the eluate shows that small amounts of mineral acids increase the conductivity of the solution. Their V_e is lower than that of the second fraction of humic acids. Therefore it is impossible to determine the alkali consumption by the second fraction and by the humic acids as a whole without their total desalting.

     

Einfluß chemischer Bodeneigenschaften auf Ausmaß und Zusammensetzung der Denitrifikationsverluste drei verschiedener Bakterien

Effect of soil properties on the quantity and quality of denitrification with different bacteria The influence of 4 different soils on the intensity and quality of gaseous denitrification losses from 3 bacteria (Aeromonas “denitrificans” S224, Azospirillum lipoferum DSM 1843 and Bacillus licheniformis ATCC 14580) was examined in model experiments at complete anaerobic conditions at the expense of a relatively high nitrate concentration (300 μg NO₃^? N/g dry soil) at standard conditions (30°C, 80% WHC). The soils (Ah-material) were obtained from gleyo-eutric Fluvisol (A), orthic Luvisol (L), calcaric Fluvisol (AR) and eutric Cambisol (KB) and represented different chemical properties. Gas production (CO₂, NO, N₂O, N₂ and CH₄) was analyzed by gaschromatography in regular intervals, whereas changes in N_t, C_t, water extractable organic carbon (C), nitrate, nitrite, ammonium, pH (H₂O) were determined at the end of each experiment. The intensity and composition of denitrification (NO, N₂O, N₂) differed considerably from organism to organism and from soil to soil. With A. “denitrificans” NO was released from the calcaric Fluvisol and orthic Luvisol, whereas B. licheniformis produced this gas only from the Cambisol. A. lipoferum did not produce NO in any of the soils tested. N₂O was liberated by A. “denitrificans” in all soils, but A. lipoferum produced it only in the Fluvisol and B. licheniformis exclusively in the Cambisol. Apparently, the production of NO and N₂O as products of incomplete denitrification at relatively high nitrate concentration is determined primarily by the organism in question and in the second place by the chemical properties of the soil. The main properties that govern the quality of denitrification in soils are discussed.