A wind tunnel for measuring the gaseous losses of environmental chemicals from the soil/plant system under field-like conditions

Abstract

Volatilization from treated areas is a major source of pesticide residues in air, fog, and rain. This may lead to long-range transport of pesticide residues to remote areas. Up to now most information on pesticide volatilization has come from laboratory experiments under controlled conditions. A new system has been designed and developed to measure the volatile losses of(14)C-labelled chemicals after application; the method compares with agricultural practice of treating soils or plants grown in lysimeters. Sensitive analytical methods guarantee a distinction between residues of unchanged pesticide, its metabolites or(14)CO2 as a mineralization product released into the air.

Mineralization and Transfer Processes of 14C-labeled Pesticides in Outdoor Lysimeters

“…For a better evaluation of pesticide leaching it is however essential to have knowledge about the factors that govern the leaching process like volatilization, degradation and mineralization. New lysimeter test systems (Stork et al 1994(Stork et al , 1997Schroll and Kühn 2004) take this into account and enable the measurement of pesticide volatilization and mineralization from lysimeter surfaces. These test systems also allow the establishment of a mass balance by which the different processes can be quantified and evaluated.…”

Significance of the Long Range Transport of Pesticides in the Atmosphere

“…Studies have been carried out under laboratory and simulated field conditions [39,[42][43][44] to simulate volatilization of pesticides under true field conditions. Similarly, studies have also been carried out under controlled conditions in the field [24,45], Laboratory and field procedures for assessment of the inherent tendency of pesticides to volatilise into the air have also been proposed [46] and compared [47,48], Whilst these types of studies can provide a means of evaluating the effects of various microclimatic parameters they are not easy to carry out, particularly for pesticides with low volatility, and results must be interpreted with care.…”

Lysimeter Experiments to Investigate the Fate of Chemicals in Soils – Comparison of Five Different Lysimeter Systems

“…These outdoor experiments permit a comprehensive study of the fate of chemicals in soil, plant and seepage water by determining the remaining 14 Cresidues in the compartments. It has been demonstrated that lysimeters with undisturbed soil monoliths reflect the field situation, referring to topsoil processes and formation of plant residues, with sufficient accuracy (Stork et al 1994;Kubiak et al 1990). But it was shown that, due to 14 C-labeled gaseous losses, it was not possible to achieve a complete 14 C-mass balance for several pesticides in these studies.…”

“…In the year 1994 a wind tunnel for measuring the gaseous losses of environmental chemicals from soil/ plant systems under field-like conditions (Stork et al 1994) was presented. This wind tunnel is placed onto lysimeter surfaces and all 14 C-pesticide residues volatilizing and mineralizing from the total plant and soil surfaces can be determined.…”

“…In virtual case studies this data set was transferred to five different lysimeter scenarios and evaluated under those various experimental conditions. The scenarios were the following: (1) application of a non-labeled chemical and the facility to determine just the parent compound, according to a study of Hesketh et al (1998) with the pesticide chlordane; (2) application of a nonlabeled chemical and the facility to identify the parent compound as well as metabolites, according to a study of Landry et al (2006) with the pesticides oryzalin and diuron; (3) application of a 14 C-labeled chemical and the facility to quantify the parent compound, metabolites and bound-residues according to the studies of Lee et al (2002) and Sequaris et al (2005), and (4) application of a 14 C-labeled chemical and the facility to measure the parent compound, metabolites, bound-residues, as well as 14 C-volatile compounds which could be determined by a windtunnel-system (Stork et al 1994). Finally the data of our lysimeter study are presented (5) with the application of a 14 C-labeled chemical and the facility to measure the parent compound, metabolites, boundresidues, as well as 14 CO 2 and 14 C-volatile compounds from soil and plant surfaces, separately.…”