The intern will carry out his/her research activities in the Department of Environmental Degradation Processes and its Remediation at the Institute of Natural Resources and Agrobiology of Salamanca (IRNASA-CSIC), within the Group of Soil and Water contamination by pesticides. The activities will correspond to those developed within the project entitled “Coupling pesticide fate modelling and conservation cropping systems to reduce the agriculture footprints on ecosystems” and they will be done under the supervision of Dr. Jesús Mª Marín Benito.
The intern will collaborate in field trials focus on studying the effect of agricultural conservation practices (no- tillage, cover crops, mulching and direct seeding) on the environmental fate of various herbicides through dissipation and mobility studies. Soil samples (surface and depth) will be taken at different times in experimental plots of agricultural soils under both cropping systems previously treated with the test herbicides. The remaining concentration of herbicides as well as the possible metabolites that are formed will be extracted and quantified. The intern will acquire training and an overview of the main processes that affect the dynamics of herbicides in soils, complementing field studies with adsorption-desorption studies (equilibrium batch method), and degradation of these compounds (and formation of their metabolites) by the different horizons of the soil in the presence and absence of cover crops residues and at different temperatures at a laboratory scale. The intern will also receive training in the determination of the different parameters that quantify the adsorption-desorption, mobility, dissipation / degradation processes that govern the dynamics of herbicides in the soil under the different types of cropping systems, their statistical study and relationship with the physicochemical properties of the soil, and its final use in pesticide fate models for a predictive use of the environmental behavior of these compounds in the long-term.
Regarding analytical techniques, the candidate will be formed in liquid and gas chromatography coupled to a mass detector for the determination of herbicides and their possible metabolites in organic and / or aqueous extracts. On a field scale, the candidate will learn the use of electric humidity probes during the monitoring of this soil property and its interpretation in both cropping systems.