Effect of Biochar Amendment and Ageing on Adsorption and Degradation of Two Herbicides     

Alena Zhelezova  Harald Cederlund  John Stenström 《Water, air, and soil pollution》2017,228(6):216

Biochar amendment can alter soil properties, for instance, the ability to adsorb and degrade different chemicals. However, ageing of the biochar, due to processes occurring in the soil over time, can influence such biochar-mediated effects. This study examined how biochar affected adsorption and degradation of two herbicides, glyphosate (N-(phosphonomethyl)-glycine) and diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in soil and how these effects were modulated by ageing of the biochar. One sandy and one clayey soil that had been freshly amended with a wood-based biochar (0, 1, 10, 20 and 30% w/w) were studied. An ageing experiment, in which the soil-biochar mixtures were aged for 3.5 months in the laboratory, was also performed. Adsorption and degradation were studied in these soil and soil-biochar mixtures, and compared to results from a soil historically enriched with charcoal. Biochar amendment increased the pH in both soils and increased the water-holding capacity of the sandy soil. Adsorption of diuron was enhanced by biochar amendment in both soils, while glyphosate adsorption was decreased in the sandy soil. Ageing of soil-biochar mixtures decreased adsorption of both herbicides in comparison with freshly biochar-amended soil. Herbicide degradation rates were not consistently affected by biochar amendment or ageing in any of the soils. However, glyphosate half-lives correlated with the Freundlich Kf values in the clayey soil, indicating that degradation was limited by availability there.  相似文献   

Localised tetanus in a cat     

Langner KF  Schenk HC  Leithaeuser C  Tholen H  Simon D 《The Veterinary record》2011,169(5):126

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Ectogenic Meromixis of Lake Hallst?ttersee, Austria Induced by Waste Water Intrusions from Salt Mining     

Harald Ficker  Hubert Gassner  Daniela Achleitner  Robert Schabetsberger 《Water, air, and soil pollution》2011,218(1-4):109-120

Lake Hallstättersee is a holomictic alpine lake, which is influenced by salt mining since the middle Bronze Age. Beside the constant saline waste water load, two massive brine spills loaded the lake with additional 16,900 tons sodium chloride (??10,250 tons Cl^?) from 1977 to 1979 and 3,000 tons salt (??1,820 tons Cl^?) in 2005. The effect of waste water intrusions from salt mining on stratification of Lake Hallstättersee was analysed over a period of 40 years. Water density, dissolved oxygen and total phosphorus (TP) concentrations were measured and an exponential model was fitted to describe the wash-out of chloride from Lake Hallstättersee after the brine spills. Furthermore, the time required returning to holomixis and steady chloride content after the second brine spill was estimated. During the whole sampling period the minimum and maximum volume-weighted annual mean chloride concentrations were 23.58 mg/L in 1979 and 3.19 mg/L in 1998. However, the mixing regime of Lake Hallstättersee, as well as the chloride concentrations, varied considerably and exhibited three holomictic and three meromictic periods between 1970 and 2009. Holomictic periods were observed when the yearly density gradient was below 0.06 kg/m³, deepwater oxygen in spring above 4 mg/L and consequently declining TP concentration in the deepest water layer below 60 mg/m³, otherwise meromictic periods were observed. Our study showed that Hallstättersee was 13 years ectogenic meromictic and 27 years holomictic during the study period.  相似文献   

Feline post‐sterilization hyphema     

Alex P. Schenk  Ann M. McGrath  Cheryl A. Beatty  Jennifer L. Ottney  Ellen K. Gratch  Sheilah A. Robertson  Andrs M. Komromy 《Veterinary ophthalmology》2020,23(3):588-591

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Nitrogen supply determines responses of yield and biomass partitioning of perennial ryegrass to elevated atmospheric carbon dioxide concentrations     

U. Schenk  H.‐J. Jäger  H.‐J. Weigel 《Journal of plant nutrition》2013,36(10-11):1423-1440

Perennial ryegrass (Lolium perenne L. cv. Parcour) grown at eight levels of nitrogen (N) fertilization (0–765 mg/pot) was exposed to ambient (390 ppm) and elevated (690 ppm) carbon dioxide (CO₂) concentrations for 83 days. Plants were cut three times and dry matter yields determined for each harvest. At final harvest, dry weight of root and stubble biomass was determined, as N concentrations of all plant fractions were determined. Carbon dioxide enrichment effects on yield and total plant biomass increased with increasing N fertilization. The weaker CO₂‐related yield enhancement at low N supply was due to the plants inability to increase tiller number. Root fraction of total plant biomass at final harvest was increased by high CO₂ and decreased by N supply. Root biomass was significantly increased by CO₂ enrichment and for both CO₂ treatments the N supply for maximum root mass coincided with the N supply for reaching maximum total plant biomass. A significant correlation between root fraction of total plant dry matter and N concentration of total plant biomass, which was not changed by CO₂ enrichment, indicates that biomass partitioning between shoot and root is controlled by the internal N status of the plant.  相似文献   

Development of soil organic matter stocks under different farm types and tillage systems in the Organic Arable Farming Experiment Gladbacherhof     

Franz Schulz  Christopher Brock  Harald Schmidt  Klaus-Peter Franz 《Archives of Agronomy and Soil Science》2013,59(3):313-326

In 1998, the Organic Arable Farming Experiment Gladbacherhof (OAFEG) was started in order to explore the impact of different organic arable production systems (mixed farming, stockless farming with rotational ley, stockless cash crop farming) and of different tillage intensities (conventional plough as a full inversion tillage, two-layer plough, inversion tillage at reduced depth, non-inversion tillage) on sustainability parameters. In this article, we present results on the development of soil organic matter (SOM) levels. Starting with organic mixed farming with approximately 0.7 livestock units (LU) per ha cattle before set-up of the experiment, only the mixed farming system in the experiment was able to maintain SOM levels. The stockless system with ley maintained soil organic carbon (SOC), but lost soil total nitrogen (STN), and the stockless cash crop system had a significant SOM loss in the magnitude of 7.7 t SOM ha^?1, or roughly 8.4% of the initial SOM mass. Reducing tillage intensity had no impact on SOM masses, but only on organic matter stratification in soils. We conclude that specialization of organic farms towards stockless arable crop production requires special attention on SOM reproduction to avoid detrimental effects. Further, reduced tillage intensity does not necessarily have a positive effect on SOM.  相似文献   

Elimination by chemotherapy of potato virus S from potato plants grown in vitro     

Heide Bittner  G. Schenk  G. Schuster  S. Kluge 《Potato Research》1989,32(2):175-179

Summary Potato virus S was eliminated from systemically infected stem cuttings of five potato cultivars after three passages in nutrient media containing 0.003% of the synthetic riboside ribavirin (Virazole). Treatment effects could be detected after only two passages which also revealed differences in cultivar response. Treated plants transferred to ribavirin-free culture media and to soil remained PVS-free. This simple method is less time-consuming than the usual meristem (axillary) tip culture procedures combined with chemotherapy or heat treatment.  相似文献   

Territoriale Schwerpunkte des Virusbefalls von Kartoffeln im Osten Deutschlands     

G. Schenk 《Potato Research》1991,34(4):459-465

Zusammenfassung Auf der Grundlage von Ergebnissen der Pflanzgutkontrolle der Jahre 1979 bis 1988 konnten ca. 77% des Gebietes der ehemaligen Deutschen Demokratischen Republik in Befallsdruckzonen der ?konomisch relevanten Virusgruppen potato leafroll virus und schwere Mosaikviren (potao virus A, potato virus M, potato virus Y) eingeteilt werden. Damit wurden die Aussagen von Schick (1952) und Pfeffer (1956) zur Verteilung der Gesundheits- und Abbaulagen best?tigt.  相似文献   

Analysis of antibiotic residues in liquid manure and leachate of dairy farms in Northern Germany   总被引：1，自引：0，他引：1  

Nicole Kemper  Harald Färber  Joachim Krieter 《Agricultural Water Management》2008,95(11):1288-1292

The scientific interest in the fate of antibiotic substances in the environment has increased during the past decades. Especially in animal husbandry, the assumed quantity of antibiotics excreted has caused major concerns as the environment can be contaminated by these compounds via different paths. In this study in Northern Germany, manure and leachate samples from dairy farms were analysed in order to verify if this kind of animal husbandry can be a source of antibiotic residues found in the environment. Neither in liquid manure nor in leachate were the analysed antibiotics detected. These results clearly show the minor importance of dairy cows as sources of antibiotic residues in the aquatic environment. To explain this fact, we propose the three following reasons: (i) the amount of antibiotics administered in dairy farming is low compared to pig or poultry production; (ii) manure storage is a useful process to minimize the antibiotic residues as the substances applied to dairy cows are sensitive to degradation processes during that period; (iii) excreted directly on grasslands, the substances degrade very quickly or adsorb to soil and are therefore not present in the leachate.  相似文献   

Population viability risk management (PVRM) for in situ management of endangered tree species—A case study on a Taxus baccata L. population     

Amalesh Dhar  Herwig Ruprecht  Harald Vacik 《Forest Ecology and Management》2008

Population viability risk management (PVRM) provides a framework for explicitly including qualitative information about the possible outcomes of a management decision with regard to the viability of an endangered population in conservation management. Multi-criteria decision-making (MCDM) techniques enables managers to select the most preferred choice of action in a context where several criteria apply simultaneously. In that context a combined approach of the PVRM concept and a MCDM technique is presented for the development, evaluation and finally ranking of the in situ conservation strategies. We discuss the concept based on a case study for the maintenance of a gene conservation forest of an English yew population (Taxus baccata L.) in Styria, Austria. As part of the PVRM the analytic hierarchy process (AHP) is used to evaluate six conservation strategies with regard to the viability of the yew population. The viability of the population is evaluated based on the results of an analysis of the current environmental, social and economical state and a characterization of the ecological parameters of its population. The most significant risk factors (illegal cutting, browsing by game, tree competition, light availability and genetic sustainability) are structured and prioritised according to their impact on the viability of the yew population applying the AHP. Effects of the six conservation strategies on the viability of the yew population are determined through a qualitative assessment of the probability of a decrease of the population along with four different environmental scenarios. In this context strategy IV combining selective thinning, protection measures, game control with public relation activities seems to be the most effective alternative. The benefits of the combined approach of the PVRM concept with the AHP for the rational analysis of conservation strategies for this endangered tree species are discussed.  相似文献