Humus balances of different farm production systems in main production areas in Austria          下载免费PDF全文

Martina Kasper  Bernhard Freyer  Kurt‐Jürgen Hülsbergen  Harald Schmid  Jürgen Kurt Friedel 《植物养料与土壤学杂志》2015,178(1):25-34

The importance of the soil humus content is indisputable. Soil humus plays an important role in preserving soil fertility and exerts great influence on plant production and yield potential. However, proofing that management‐related changes in the stock of soil organic matter (SOM) have taken place against the background of spatial and temporal variation is a difficult task. In most cases, sampling over a long period of time is needed to verify these changes. Alternatively, potential changes in the SOM stock can be estimated using humus balancing models, which help to identify the need for humus reproduction on a farm. In general, a humus balance is the difference between the humus demand of cultivated crops and humus supply through crops and organic fertilizers. In this study, the ‘Dynamic Humus Unit Method' within the modelling program REPRO was applied to calculate the humus balance for 29 model‐farms that are representative of most of the agricultural production in Austria. Each model‐farm represents a specific production type (PT) and farming system in a defined region or main production area (MPA). This approach gives an overview of the humus balances at a large scale and allows a general trend in Austria to be estimated. Besides differing between conventional and organic farming systems, specific site conditions can also be selected in the model. The constructed model‐farms belong to different PTs such as “forage production”, “cash crops”, “refinement”, and “permanent crops”. The PT “permanent crops” refers to the cultivation of wine. The cropping system of each PT was analyzed in detail, while livestock keeping was considered only when applicable. Positive humus balances were found for all PTs except for permanent crops. The results ranged from –122 to 890 kg C ha^?1 y^?1. Regions and farm structure, e.g., forage production compared to cash crop, were found to have a greater influence than the kind of farming system (i.e., organic vs. conventional farming). Comparing the different PTs, forage production had the highest positive humus balances (219 to 890 kg C ha^?1 y^?1), followed by cash crop (24 to 239 kg C ha^?1 y^?1), refinement (–64 to 402 kg C ha^?1 y^?1) and permanent crops (–122 to –38 kg C ha^?1 y^?1). Regarding the farming system, organic farming led to more humus accumulation than conventional farming due to a higher share of fodder legumes and catch crops and more diverse crop rotations. The results were within the range of available empirical data on SOM change, and it was therefore concluded that the results are reasonable. In general, humus reproduction can be regarded as sufficient for agricultural production.  相似文献   

Genetic Introgression Between Arctic Charr (Salvelinus Alpinus) and Brook Trout (Salvelinus Fontinalis) in Bavarian Hatchery Stocks Inferred from Nuclear and Mitochondrial DNA Markers     

Riho Gross  Bernhard Gum  Reinhard Reiter  Ralph Kühn 《Aquaculture International》2004,12(1):19-32

Nuclear insulin-like growth factor 2 gene (IGF-2), growth hormone 1 gene (GH-1) and internal transcribed spacer 1 (ITS-1) of the ribosomal DNA as well as the mitochondrial NADH-3 and NADH-4 dehydrogenase genes (ND-3/4) exhibited species-specific restriction fragment patterns and three microsatellite loci (Sfo18, Ssa85 and Ssa197) had non-overlapping allele size ranges in Arctic charr and brook trout and were used as diagnostic markers for testing genetic purity of hatchery stocks and wild populations of Arctic charr and brook trout in Bavaria, Germany. Screening of four wild populations (three in Arctic charr and one in brook trout) revealed only a single hybrid (back-cross to brook trout) individual in L. Starnberg. In contrast, in three (out of five) hatchery stocks of Arctic charr and in both hatchery stocks of brook trout hybrids were detected with the frequency from 3 to 100%. Three hatchery stocks (SS2, SA and BS1) represent a hybrid swarm because they contained a very high proportion of hybrids (from 83 to 100%) and most or all hybrid individuals had alien alleles at only one or a few of six unlinked diagnostic loci, indicating that post-F₁ hybrids represent the majority of individuals in these stocks and introgression has taken place. Release or escape of introgressed individuals from hatcheries into natural water bodies should be avoided in order to protect the biological diversity and genetic integrity of native fish populations.  相似文献   

The effects of extrusion and pelleting of feed for trout on the digestibility of protein,amino acids and energy and on feed conversion     

Bernhard Vens-Cappell 《Aquacultural Engineering》1984,3(1):71-89

One feeding and two digestion experiments were performed in order to study the effect of feed processing by extrusion and pelleting on feed conversion and on the digestibility of energy, protein and amino acids. Feed conversion was 1·24 when trout was reared on an extruded diet as compared with 1·61 when reared on the same but pelleted diet. The specific growth rates of 1·56 and 1·55%, respectively, attained with both diets, were almost identical due to a depression of voluntary intake of the extruded diet. The effect of different daily feed intakes in percentage of body weight (NI, %) on the digestibility of energy (D, %) could be described using the following linear regression equations: D(%) = 78·3 ? 5·9 NI(%) for the pelleted diet and D(%) = 87·5 ? 3·9 NI(%) for the extruded diet. Though conversion of the extruded and pelleted diets differed significantly the digestible energy needed to produce 1 kg of gain was nearly the same, 17 370 kJ and 17 580 kJ respectively, indicating that differences in conversion were due to the digestible energy content. The digestion coefficients of the protein and amino acids were not influenced significantly (p < 0·05) by a change in the feed process, but different digestion coefficients for individual amino acids were observed. The use of digestible carbohydrate for trout nutrition is limited by the incidence of liver degeneration.  相似文献   

A critical reflection on the success of rearing and culturing juvenile freshwater mussels with a focus on the endangered freshwater pearl mussel (Margaritifera margaritifera L.)     

Bernhard Gum  Michael Lange  Juergen Geist 《水产资源保护:海洋与淡水生态系统》2011,21(7):743-751

Environment and tree size controlling stem sap flux in a perhumid tropical forest of Central Sulawesi,Indonesia     

Viviana Horna  Bernhard Schuldt  Sarah Brix  Christoph Leuschner 《Annals of Forest Science》2011,68(5):1027-1038

• Introduction   

We studied stem sap flux density in seven common tree species in a perhumid tropical rainforest at pre-montane elevation in Sulawesi with the aims (1) to analyse the among-species variation in flow patterns, (2) to search for an assumed convergence in the response to controlling environmental factors, and (3) to investigate the effect of tree size on xylem flux.  相似文献   

Advanced-backcross QTL analysis in spring barley: IV. Localization of QTL × nitrogen interaction effects for yield-related traits     

Bernhard Saal  Maria von Korff  Jens Léon  Klaus Pillen 《Euphytica》2011,177(2):223-239

The advanced backcross quantitative trait locus (AB-QTL) analysis has proven its usefulness to identify and localize favourable alleles from exotic germplasm and to transfer those alleles into elite varieties. In a balanced design with up to six environments and two nitrogen fertilization (N treatment) levels, a 4-factorial mixed model analysis of variance (ANOVA) was used to identify QTL main effects, QTL × environment interaction effects and QTL × N treatment interaction effects in the spring barley BC₂DH population S42. The yield-related traits studied were number of ears per m², days until heading, plant height, thousand grain weight (TGW) and grain yield. In total, 82 QTLs were detected for all traits. This finding was compared to a previous QTL study of the same population S42, where the current field data was reduced to one half through restriction of the analysis to the standard N treatment level (von Korff et al., Theor Appl Genet 112: 1221–1231, 2006). These authors located 54 QTLs for the same traits by applying a 3-factorial mixed model similar to the current model but excluding the factor N treatment. We found that QTL × environment interaction, alone or in combination, accounted for 24 of the newly uncovered QTLs, whereas QTL × N treatment interaction was of lesser importance with six new cases in total. A valuable QTL interacting with N treatment has been identified on chromosome 7H where lines carrying the wild barley allele were superior in number of ears per m² in either N treatment. We conclude that in population S42 the extension of the phenotype data set and the inclusion of N treatment into the mixed model increased the power of QTL detection by providing an additional replication rather than by revealing specific N treatment QTLs.  相似文献   

Validierung eines 2-Regionen-Modells zur Simulation des Stofftransportes im Boden anhand von Laborsäulen- und Feldversuchen     

Bernhard Wagner  Reinhold Funk  Franz-Xaver Maidl 《植物养料与土壤学杂志》1997,160(2):309-316

Validation of a 2-domain-model for the simulation of solute transfer in soils by laboratory and field experiments The simulation of water and solute transfer in the unsaturated zone on the basis of the classical convective dispersive model gives dissatisfactory results in many cases. Especially in the zone of evapotranspiration the observed penetration depths of surface-applied chemicals often exceed calculated values. This has been attributed to preferential flow in domains with accelerated flow. The aim of the investigations presented here was to extend the conventional theory of solute transfer in order to enable improved model predictions without introducing too much complexity to the model which might reduce its applicability. The mobile-immobile-concept of Coats and Smith (1964) was chosen to extend the model FLOTRA (Wagner et al., 1992), which is based on the convective dispersive approach. The model parameters additionally needed by the model are the immobile water content θ_im and the solute transfer coefficient α. The applicability of the model was tested on the basis of several laboratory and field experiments. It is shown, that with the mobile-immobile-approach modeling results of water and solute transfer in the top soil layers, which are most important in view of soil and groundwater protection, were improved compared to the calculations with the classical convective dispersive model.  相似文献   

Adsorption von Wasser, Äthylenglycolmonoethyläther sowie Stickstoff und ihre Beziehung zu Eigenschaften deutscher und israelischer Bodenproben     

Andreas Schulte  Amos Banin  Bernhard Ulrich 《植物养料与土壤学杂志》1992,155(1):43-49

Adsorption of Water, Ethylene Glycol Monoethyl Ether as well as Nitrogen and its Relation to Properties of German and Israeli Soil Samples To determine the specific surface area, samples taken from 140 soil horizons were selected and the significant physical and chemical properties were investigated. The specific surface area of the samples was determined by adsorption of H₂O, ethylene glycol monoethyl ether (EGME) and N₂. A comparison of the three methods shows that the specific surface area determined by the adsorption of H₂O and EGME does not differ significantly. However, the specific surface determined by N₂-adsorption differs markedly from the results obtained using the polar substances. As a dependent variable the specific surface area is mainly influenced by the clay content and clay mineral type. Further, the organic substance content as well as the iron- and manganoxide content have a more significant influence on the specific surface area the lower the clay content is, or the content of three layer minerals. As an independent variable, the specific surface area determined by adsorption of EGME, proved to be the characteristic soil factor which reflects the effective cation exchange capacity as well as the hygroscopicity with the highest degree of accuracy.  相似文献   

The dynamics of groundwater table and salinity over 17 years in Khorezm   总被引：1，自引：0，他引：1  

Mirzakhayot Ibrakhimov  Christopher Martius  J.P.A. Lamers  Bernhard Tischbein 《Agricultural Water Management》2011,101(1):52-61

Salinization of irrigated agricultural land threatens ecological sustainability and livelihoods of people. Salinization is especially severe in the dry lowlands world-wide and in Central Asia where large amounts of salts accumulated in the soil profile, originating from shallow saline groundwater (GW). Analysis of the unique dataset of 2000 monitoring wells of GW table and salinity in lowland Khorezm region of Uzbekistan over the period of 1990 till 2006 showed shallow GW levels of 1.1-1.4 m (±0.48-0.66 m) at start of leaching periods and 0.9-1.4 (±0.43-0.63 m) in July during the annual growing seasons. While leaching efficiency is decreased, shallow GW in July is far above the optimum levels of 1.4-1.5 m. The effects of topography, soil texture, and irrigation and drainage networks were found to favor shallow GW forced by excessive water diversion. The drainage network, which is seen by many specialists as underdeveloped and its improvement necessary to arrest unacceptable GW levels, is being used under its full capacity. The solution to alleviate land degradation is not only an improved drainage, but better controlled and more flexible water management.  相似文献   

Treatment of bullous keratopathy with corneal collagen cross‐linking in two dogs          下载免费PDF全文

Simon A. Pot  Nicolin S. Gallhöfer  Ladina Walser‐Reinhardt  Farhad Hafezi  Bernhard M. Spiess 《Veterinary ophthalmology》2015,18(2):168-173

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