Mineralization and Transfer Processes of <Superscript>14</Superscript>C-labeled Pesticides in Outdoor Lysimeters

A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of ¹⁴C-labeled substances in soil–plant–atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between ¹⁴C-emissions from soil surfaces and ¹⁴C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate – using the two-chamber-lysimeter-test-system – are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil–plant-systems. Mineralization of ¹⁴C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide ¹⁴C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules.     

The influence of south Foehn on the ozone distribution in the Alpine Rhine valley—results from the MAP field phase

During the Mesoscale Alpine Programme (MAP) special observation period (SOP) between 7 September and 15 November 1999, ground-based and airborne measurements have been conducted in the Rhine valley south of the Lake of Constance to investigate the unstationary aspects of Foehn and related phenomena, like the impact of Foehn on the ozone concentrations in the valley. Foehn events occurred with above-average frequency and high diversity. Foehn induced ozone peaks in October and November are found to be much lower than the September Foehn case of the period. An inversion layer in the lake area with ozone concentrations below 10 ppb often shields the monitoring stations from the Foehn air aloft. Trajectory calculations for the Foehn period between 19 and 24 October 1999 reveal that the Foehn air originated from below 1 to 1.5 km above the Po Basin and the Mediterranean Sea. Tethered balloon soundings in the source area south of the Alps, ozone measurements at the mountain station Jungfraujoch (3580 m a.s.l.) and airborne measurements across the Alpine crests reveal that the ozone levels found in the Foehn air correspond to the concentrations just above the mixing height in the Po Basin and are transported across the Alpine crest within the lowest flow layer.     

Statistische Aus- und Bewertung immissionsbedingter Bodenbelastungen

The contamination of soils with pollutants by human activities has increased over a period of some decades. Deposited pollutants are immobilized in different ways depending on their chemical properties, or they are biologically available. This potential hazard requires a permanent control. An extensive investigation of topsoil in the surroundings of the fertilizer factory at Dorndorf-Steudnitz (Thuringia) was carried out to assess the size and extension of contamination and to estimate the potential risk which originates from the deposited pollutants. The fertilizer factory at Dorndorf-Steudnitz was one of the biggest dust emission sources in the middle part of the Saale river valley. Considerable damages of vegetation could be noticed already in the seventies and eighties. The trees and other plants in the neighbourhood of the factory died. The loadings of the investigated area may be attributed to a direct influence of gaseous and also of dustlike pollutants on the vegetation and resorption from the soil. Frequently, the content of pollutants in soils varies considerably. For this reason a univariate statistical evaluation of the data is not usually adequate. The use of geostatistical methods permits the characterization of the spatial structure of the investigated area and the undistorted assessment of the pollutant contents at unsampled points. The degree and extension of the contamination can be determined on the basis of the kriging estimation. The classification of analyzed features in regard to common sources of contamination can be realized by means of methods of multivariate data analysis.     

COMPRENDO Summa Summarum — Abschlusstagung des EU-Projektes COMPRENDO am 17. M?rz 2006 in Frankfurt am Main

Tagungsankündigungen

COMPRENDO Summa Summarum — Abschlusstagung des EU-Projektes COMPRENDO am 17. M?rz 2006 in Frankfurt am Main