Ecology,classification and soil pattern of colluvial soils of the bornhoeved lake district (North-Germany)

Water erosion causes the accumulation of soil material, especially at the bottom slope and in landscape depressions. According to FAO-UNESCO (1990) colluvial soils can be classified as Cumuli-Aric Anthrosols if the minimum thickness of the altered topsoil is 5 dm or more. These soils are characterized by addition of small amounts of soil material that has been incorporated into the underlying material by tillage and/or turbation. As a result of geological factors and land-use intensities, Cumuli-Aric Anthrosols differ markedly in their ecological properties. In the study area ‘Bornhoeved Lake District (Schleswig-Holstein, North-Germany)’ soil patterns have been investigated showing the interdependence of soil landscapes and their soil units by water erosion and accumulation. Examples of various colluvial soils in catenary sequences in the study area are presented. Colluvial soils in the study area are characterized by a layer thickness between 5 and 14 dm and show significantly higher quantities of organic matter, nitrogen and plant-available water in comparison with eroded soils.     

Investigation on Soil Lipid Extraction with Different Organic Solvents

Soil lipid content is an important characteristic of the soil organic matter. One of the commonly used extractants for the determination of soil lipid is benzene/ethanol 1:1(v/v). In this study the toxic solvent mixture benzene/ethanol was substituted with the less harmful one toluene/ethanol 1:2.3 (v/v). Both solvent mixtures give a comparably high recovery of soil lipid and the composition of both lipid fractions are very similar according to their thin layer chromatography (TLC). Further investigations with NMR-spectroscopy confirmed that the extracted lipid fraction consists mainly (7gt;90%) of structure elements of aliphatic hydrocarbons.     

Enantioselective catalysis for agrochemicals: synthetic routes to (S)-metolachlor, (R)-metalaxyl and (αS,3R)-clozylacon

The application of enantioselective catalytic methods for the technical preparation of chiral agrochemicals is illustrated for three active ingredients of the acylanilide type. The key step for the technical synthesis of the herbicide (S)-metolachlor is the enantioselective hydrogenation of an imine intermediate using a novel iridium ferrocenyldiphosphine catalyst with an unprecedented high activity and 80% ee. (R)-metalaxyl and (αS,3R)-clozylacon were synthesized via the enantioselective hydrogenation of corre-sponding enamide precursors with Rh and Ru/binap catalysts with >95% and 99% enantiomeric purity, respectively. © 1998 Society of Chemical Industry     

Extending Finlay–Wilkinson regression with environmental covariates

Finlay–Wilkinson regression is a popular method for analysing genotype–environment interaction in series of plant breeding and variety trials. It involves a regression on the environmental mean, indexing the productivity of an environment, which is driven by a wide array of environmental factors. Increasingly, it is becoming feasible to characterize environments explicitly using observable environmental covariates. Hence, there is mounting interest to replace the environmental index with an explicit regression on such observable environmental covariates. This paper reviews the development of such methods. The focus is on parsimonious models that allow replacing the environmental index by regression on synthetic environmental covariates formed as linear combinations of a larger number of observable environmental covariates. Two new methods are proposed for obtaining such synthetic covariates, which may be integrated into genotype-specific regression models, that is, criss-cross regression and a factor-analytic approach. The main advantage of such explicit modelling is that predictions can be made also for new environments where trials have not been conducted. A published dataset is employed to illustrate the proposed methods.