Soil amendment with sewage sludge-derived chars increases C-sequestration potential and provides N and P for plant growth during a second cropping period with Lolium perenne     

Blanca Leiva-Suárez  Marina Paneque  José María De la Rosa  José Antonío González-Pérez  María José Leiva  Heike Knicker 《European Journal of Soil Science》2021,72(3):1256-1269

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Measurement of soil water tension in single aggregates with use of the filter paper method     

Heike Bohne  Michael J. Savage 《植物养料与土壤学杂志》1991,154(2):143-146

The filter paper method was used to establish the retentivity curves of single aggregates. Aggregates (diameter 3-4 cm) from an Alfisol (sandy loam) and a Mollisol (sandy clay) were used. The aggregates had different water contents. Whatman No. 42 filter paper, attached to a conical plastic tube on the end of a rod, was inserted into a hole made in the aggregate. The hole was made using a small corer. The aggregates were sealed in wax, put into a plastic bag and stored in a thermo-constant room to equilibrate. After seven days the water content of the aggregates and of the filter papers were determined at 105°C. Retentivity curves for the aggregates are presented and sources of error are discussed.  相似文献   

Recent advances in the spectroscopic characterization of soil humic substances and their ecological relevance     

Rüdiger Fründ  Georg Guggenberger  Konrad Haider  Heike Knicker  Ingrid Kgel-Knabner  Hans-Dietrich Lüdemann  Jrg Luster  Wolfgang Zech  Michael Spiteller 《植物养料与土壤学杂志》1994,157(3):175-186

Non destructive spectroscopic methods such as ¹³C- and ¹⁵N-NMR provide new insights into the structure of humic substances. Solid state NMR is capable of studying complete native soils by the CPMAS-technique. By means of nitrogen 15-enriched composts it is suggested that nitrogen in soil organic matter is mainly located in amide and peptide structures. Most probable assignments are given. The investigation of humification processes in forest soils is possible via an approach which uses several fractionation techniques in combination with degradative and non-degradative analytical techniques. Besides structure analysis, the ¹³C-NMR-spectroscopy provides important information about the functions of humic substances. By using ¹³C-enriched xenobiotics the binding mechanism to organic matter can be elucidated on a molecular basis. Molecular fluorescence spectrometry, a non-invasive method, is a powerful tool for the quantitative characterization of metal ion complexation by dissolved organic matter in aqueous leaf litter extracts in terms of conditional stability constants and metal binding capacities.  相似文献   

Microscale-scale measurement of potential nitrification rates of soil aggregates     

Heike Hoffmann  Michael Schloter  Berndt-Michael Wilke 《Biology and Fertility of Soils》2007,44(2):411-413

To improve our knowledge about the effect of soil structure on potential nitrification (PN) rates in different soil aggregate fractions, we adapted and validated the standard method based on International Organization of Standardization (ISO) 15685 to small sample volumes. This assay was used to determine the distribution of PN in soil aggregates obtained from three different sites (natural grassland, agricultural land and forest). Overall, the external surface layers of the aggregates showed higher PN rates than the interior fractions of the aggregates. These differences were more clear in clayey than in sandy soils.  相似文献   

Fire-induced transformation of C- and N- forms in different organic soil fractions from a Dystric Cambisol under a Mediterranean pine forest (Pinus pinaster)     

Heike Knicker  Francisco J. González-Vila  José A. González 《Soil biology & biochemistry》2005,37(4):701-718

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Pressure/temperature combined treatments of precursors yield hormone-like peptides with pyroglutamate at the N terminus     

Fernández García A  Butz P  Trierweiler B  Zöller H  Stärke J  Pfaff E  Tauscher B 《Journal of agricultural and food chemistry》2003,51(27):8093-8097

Peptides containing the cyclic product of glutamine at the N terminus are usually biologically active. If the cyclization of glutamine was associated with a volume reduction, pressure should displace the equilibrium in the direction of the lower volume. Here, results in model solutions and in whey are discussed, showing that the theorized cyclization of glutamine in Gln-His-ProNH(2) or Gln-Leu-ProNH(2) is significantly accelerated during the application of heat and even more strongly when elevated temperature and pressure combinations are used. The reaction rate depended on the intensity of the pressure treatment, the pH, and the nature of the amino acids adjacent to glutamine. The products of the reaction were identified as thyrotropin-releasing hormone (TRH) and [Leu(2)]TRH. The reported reactions could affect the naturally balanced concentration of short-chain peptides in foods and therefore induce unpredictable biological effects.  相似文献   

Development of water potential gradients in non-rooted aggregates in relation to aggregate size and relative humidity of the air     

Heike Bohne  K.H. Hartge 《Soil & Tillage Research》1990,17(3-4):231-240

In pot experiments with rye-seedlings, it was investigated how the size of non-rooted artificially made spherical aggregates influences the development of water potential gradients in the aggregates and the utilization of water. The experiments were carried out with constant low (40%) and high (70%) relative humidity, and with changing low (40–60%) and high (70–90%) relative humidity. Material from a clay soil (52%<2μm) was used. The mean gradient of water potential developing in the aggregates during the course of drying increased with decreasing aggregate size. For constant relative humidity, loss of water from the aggregates increased with increasing mean gradient of water potential. For changing relative humidity, loss of water from the aggregates was independent of the mean gradient of water potential and hence from aggregate size. It is discussed that the change in relative humidity allows a certain redistribution of water in the aggregates which makes the water in the centre of large aggregates accessible to roots.  相似文献   

A proposal of interpretive criteria for cefoperazone applicable to bovine mastitis pathogens     

Fessler AT  Kaspar H  Lindeman CJ  Stegemann MR  Peters T  Mankertz J  Watts JL  Schwarz S 《Veterinary microbiology》2012,157(1-2):226-231

The correct assessment of mastitis pathogens for their susceptibility/resistance to cefoperazone is currently hampered by the lack of harmonized test conditions and interpretive criteria. The aim of this study was to provide a proposal for clinical breakpoints of cefoperazone which are applicable to Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis from cases of bovine mastitis and better reflect the situation in the bovine udder than breakpoints adopted from human medicine. For this, pharmacological data and clinical efficacy data of the documents submitted for approval of cefoperazone have been revisited. In addition, 1086 bacterial pathogens of the aforementioned six species/groups collected in Germany and in the USA during recent years were tested in parallel for their cefoperazone MICs and the zone diameters using a 75 μg disk. Subsequently, MICs were plotted against zone diameters. Based on the pharmacological data, the clinical efficacy and the microbiological data, a proposal was made for veterinary-specific breakpoints which classify members of the aforementioned species/groups as (a) susceptible to cefoperazone when their MIC is ≤ 2 μg/ml and their zone diameters are ≥ 27 mm (staphylococci or E. coli) or ≥ 21 mm (streptococci), (b) intermediate when their MIC is 4 μg/ml and their zone diameters are 22-26 mm (staphylococci or E. coli) or 16-20mm (streptococci), and (c) resistant when their MIC is ≥ 8 μg/ml and their zone diameters are ≤ 21 mm (staphylococci or E. coli) or ≤ 15 mm (streptococci).  相似文献   

Local knowledge helps select species for forest restoration in a tropical dry forest of central Veracruz, Mexico     

Alfonso Suárez  Guadalupe Williams-Linera  Carlos Trejo  Juan Ignacio Valdez-Hernández  Víctor Manuel Cetina-Alcalá  Heike Vibrans 《Agroforestry Systems》2012,85(1):35-55

Species for restoration forestry on degraded lands in the tropics are often restricted to a few well-known exotic timber species. This selection frequently leads to failed projects, as local people expect trees to cover a number of uses, not only timber. We studied local knowledge of the usefulness, scarcity and importance for wildlife of native tree species in central Veracruz, Mexico, a region with mainly secondary vegetation and remnants of tropical dry forest. Data were obtained from several workshops, in depth interviews of 40 key informants, field walks with informants, and botanical collections. Analysis included indices for cultural importance, scarcity and wildlife relevance. We documented 76 species in one or more of the categories, from primary, secondary, agroforestry and riparian habitats. Fabaceae was the most important family. All of the species were useful for humans, mainly for rural construction, food, fence posts and fuel. Two-thirds of the species were considered scarce though they were not necessarily rare??some were highly useful, overexploited species with populations insufficient for demand; this category included five of the ten most important species culturally. Also, two-thirds of the tree taxa were considered important for wildlife, especially species of Moraceae. The study shows that the local population is highly aware of the varying functions of trees in the landscape. However, few of the important species are available from regional nurseries. We propose a number of species for restoration forestry, agroforestry systems and enrichment plantings that would be valued by landowners.  相似文献   

Humic substances and nature-like technologies     

Perminova  Irina V.  García-Mina  José-María  Knicker  Heike  Miano  Teodoro 《Journal of Soils and Sediments》2019,19(6):2663-2664

Journal of Soils and Sediments -  相似文献