Heinrich Wilhelm Weber 《Forstwissenschaftliches Centralblatt》1920,42(11):385-399

Ohne Zusammenfassung  相似文献   

Estimates of additive and dominance effects for Fusarium head blight resistance of winter triticale     

G. Oettler    N. Heinrich  T. Miedaner 《Plant Breeding》2004,123(6):525-530

The most effective strategy to control Fusarium head blight (FHB), a devastating disease of small‐grain cereals, is breeding resistant cultivars. This resistance study of F₁ crosses, F₂ and backcross generations of triticale estimates heterosis, general and specific combining ability (GCA, SCA), additive and dominance effects and compares parents with segregating generations. The genetic material consisted of 10 parents with their 45 F₁ crosses and of six parents with their 15 F₂ progeny and backcrosses to each parent. Genotypes were grown in various environments and artificially inoculated with an aggressive isolate of F. culmorum. FHB was assessed, by visual rating, as the mean of four to five individual ratings of disease development. Heterosis for FHB was of little importance. The correlation between the FHB rating of F₁ crosses and their mid‐parent performance was close. GCA was the predominant source of variation, although the significance of the SCA variance also implied non‐additive allelic interaction. The preponderance of additive gene effects is encouraging for increasing resistance by a recurrent selection programme. The relationship between the GCA effect of a parent and its per se performance was close, which gives the possibility of predicting FHB resistance in F₁ crosses. Additive effects were predominant in the F₂ progeny and also in the backcrosses. Transgressive segregants could not be detected. Searching for them should be postponed to the F₃ or later generations.  相似文献   

Estimating soil stress distribution by using depth‐dependent soil bulk‐density data     

Jrg Bachmann  Karl Heinrich Hartge 《植物养料与土壤学杂志》2006,169(2):233-238

Depth‐dependent soil bulk density (BDS) is usually affected by soil‐specific factors like texture, structure, clay mineralogy, soil organic‐matter content, soil moisture content, and composition of soil solution and is also affected by external factors like overburden‐stress history or hydrological fluxes. Generally, the depth‐dependent BDS cannot be predicted or extrapolated precisely from a limited number of sampling depths. In the present paper, an easy method is proposed to estimate the state of soil mechanical stress by analyzing the packing characteristics of the profile using soil bulk‐density data. Results for homogeneous loess profiles exposed to the site‐specific climatic conditions show that the depth‐dependent relation of void ratio vs. weight of overburden soil can be described systematically so that deviations from the noncompacted reference state can be detected. We observed that precompaction increased from forest soils (reference) to agricultural soils with decreasing depth.  相似文献   

The Age of E-mail Submission has passed – The Age of ESS Submission has arrived     

Ulrich Förstner  Wim Salomons  Zhihong XU  Almut Beate Heinrich 《Journal of Soils and Sediments》2006,6(2):68-74

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Ermittlung des Spannungszustandes von Böden aus Werten des Eindringwiderstandes von Sonden     

Karl Heinrich Hartge  Jrg Bachmann 《植物养料与土壤学杂志》2004,167(3):303-308

Evaluation of the soil consolidation state by using data from penetration resistance probes Penetration resistance data (EW) from handdriven equipment are easily obtainable because the equipment is simple, cheap, and easily carriable. Measurements are performed quickly without extensive destruction of the site. It is the only method to measure soil strength directly and in situ. Therefore, it is worthwhile to propose an interpretation of the results in order to obtain more conclusive statements on the structural soil state. The procedure applied in our study consists in assigning EW values to the principal stress σ_x and in using an auxiliary construction for the vertical component (σ_z ) as a function of penetration depth. The EW value obtained at the final soil depth is assumed to represent stresses at rest, i.e., K₀ = σ_x/σ_z = 1. Drawing a straight line from this point towards the origin of the coordinates EW and soil depth supplies values of the hydrostatic condition for each depth; e.g., values for σ_z are available for each depth. The coefficient for the equivalent stress at rest (K_0E) per depth can now be calculated simply by comparing the measured EW values with the assumed (hydrostatic) vertical depth function of EW. From a total volume of 29 sets of EW versus depth relations, means and standard deviation of K_0E are presented for arable and forest soils from central Europe. K_0E of forest soils tends to be close to 1 showing approximately normal compaction. In arable sites, K_0E > 2 prevail, indicating precompation. These results confirm the general feasibility of the approach to evaluate the compaction state of soil from EW data. Examples are given to show the K_0E characteristics for special cases of mechanical stress situations.  相似文献   

The New JSS-Framework: Subject Areas and Editors, The ESS and Other News     

Almut Beate Heinrich 《Journal of Soils and Sediments》2006,6(2):67-67

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A gas-flow soil core method to measure field denitrification rates     

Timothy B. Parkin  Heinrich F. Kaspar  Alan J. Sexstone  James M. Tiedje 《Soil biology & biochemistry》1984,16(4):323-330

A method was developed for rapid measurement of soil denitrification under conditions where natural soil structure and aeration status is maintained. Air was continuously recirculated by means of a membrane pump through a soil core and a sample loop of a gas chromatograph equipped with an electron capture detector. Addition of acetylene to the recirculating air permitted measurement of denitrification in the soil core. Because of the rapid distribution of C₂H₂ and removal of N₂O provided by the gas flow, denitrification rates could usually be determined in less than 2 h. By means of external 6-way and 8-way valves, four soil cores could be simultaneously analyzed on one gas Chromatograph equipped with dual detectors. Soil cores could also be stored at 4°C for later analysis without affecting the denitrification rate. The detection limit for denitrification rate measurements was 0.5 ngN g^?1 soil day^?1 or approximately 2.6 g N ha^?1 day^?1. Coefficients of variation for repeated measurements on the same soil core were usually less than 15%, but coefficients of variation for repacked or natural cores of the same soil were much higher (70–90%) Disruption of the natural soil structure by sieving increased the denitrification rate in an aggregated clay loam soil, but decreased the rate in a non-aggregated sandy soil. These results illustrate the importance of maintaining natural soil structure during denitrification measurements. The effect of pumping gas through soil was evaluated by comparing denitrification rates in soil cores where C₂H₂ was allowed to distribute into the soil by passive diffusion with rates obtained by pumping. Lower denitrification rates were observed in the static incubation presumably due to limited diffusion of C₂H₂ into or N₂O out of the denitrifying sites in the soil. This diffusion limitation could be overcome in the static incubations if C₂H₂ was initially distributed through the soil by pumping. This gas flow method is well suited to the study of soil denitrification rates under nearly natural conditions because the indigenous substrates and anaerobic microsites are preserved, the rapidity in which denitrification rates can be measured, and the high sensitivity and relatively low analytical variability of the method.  相似文献   

Einfluß langjähriger Gülledüngung auf den Nährstoffhaushalt des Bodens. 2. Mitteilung: Bindung und Löslichkeitskriterien der Bodenphosphate     

Wilfried Werner  Friedhelm Fritsch  Heinrich W. Scherer 《植物养料与土壤学杂志》1988,151(1):63-68

Influence of long-term slurry application on soil nutrients. 2. Fractions and solubility criteria of soil phosphorus Fractions and solubility criteria of soil phosphorus accumulated by long-term slurry application were investigated. The following results were obtained:

• – Slurry application mainly resulted in higher concents of inorganic phosphorus, especially Fe-Al-P, even in deeper soil layers.
• – The accumulation of inorganic phosphorus resulted in an increase of phosphorus availability in all conventional extraction methods used, as well as in higher phosphorus concentration of the soil solution.
• – In the upper soil layers of luvisols and in the deeper soil layers of diluvial sandy soils organic phosphorus was enriched, but did not significantly influence phosphorus intensity and delivery.
• – Compared to soils supplied with mineral fertilizers there are no particularities in phosphorus dynamics, from which differences in the interpretation of “available” phosphorus values with respect to phosphorus recommendation scales could be concluded.

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Ist der Konzentrationsfaktor k eines aggregierten Bodens als steuernde Größe der mechanischen Druckverteilung in Böden eine Konstante?     

Hans Heinrich Becher 《植物养料与土壤学杂志》2004,167(4):525-531

Is the concentration factor k of an aggregated soil constant as the determining measure for the stress distribution in soils? The mechanization of agriculture as well as of forestry has led to a pronounced increase of the load of equipments used for field operations. The harvesting machineries reach about 60 metric tons (sugarbeet harvester) when fully loaded thereby exceeding the allowed threshold weight of 40 metric tons for vehicle traffic on roads in Germany. These high loads cause severe soil compaction which contradicts to the German Federal Law for Soil Protection. Therefore, it is necessary to consider the pressure transfer within a soil profil. It is demonstrated by means of some examples that the controlling measure for the pressure transfer within soils, the concentration factor k, is temporarily as well as spatially affected by nature (e.g., soil genesis, soil water content) and/or by human activity (e.g., soil tillage, harvest). This unavoidable and variable impact complicates the estimation of the theoretical depth and distance to which soil compaction may reach, when measuring it by using only few sensors. For even during the passage of a combination of tractor and pulled equipment, the conditions of soil compaction change. Thus, the concentration factor k cannot be considered a soil constant.  相似文献   

PDGFRA activating mutations in gastrointestinal stromal tumors     

Heinrich MC  Corless CL  Duensing A  McGreevey L  Chen CJ  Joseph N  Singer S  Griffith DJ  Haley A  Town A  Demetri GD  Fletcher CD  Fletcher JA 《Science (New York, N.Y.)》2003,299(5607):708-710

Most gastrointestinal stromal tumors (GISTs) have activating mutations in the KIT receptor tyrosine kinase, and most patients with GISTs respond well to Gleevec, which inhibits KIT kinase activity. Here we show that approximately 35% (14 of 40) of GISTs lacking KIT mutations have intragenic activation mutations in the related receptor tyrosine kinase, platelet-derived growth factor receptor alpha (PDGFRA). Tumors expressing KIT or PDGFRA oncoproteins were indistinguishable with respect to activation of downstream signaling intermediates and cytogenetic changes associated with tumor progression. Thus, KIT and PDGFRA mutations appear to be alternative and mutually exclusive oncogenic mechanisms in GISTs.  相似文献