Evaluation of the action on the hydrographic area of Auradé (Gers)

Abstract

The first aim of this study was the evaluation of the impact of agricultural production on the stream water quality. After this first statement of the water quality degradation, an action was launched in order to recover the quality of the resource. Grassed buffer strips devices were settled along the stream to demonstrate the efficiency of these protections in the reduction of the contamination. The following step is the improvement of the agricultural practices, by limiting chemicals treatments, and by a global approach on the crop rotations. Aware of the water quality results, a technical work group thought about the practices of the main crops of the area: sunflower and wheat. The protocol indicates the appropriated strategies of weed control, specifies for each pest, the periods, observations, treatment thresholds, and appropriated chemical products, and evaluates technically and economically these new itineraries. A list of products is proposed to the farmers in order to substitute or diversify depending on the efficacy, the characteristics of the substances, and the chemical products available on the two local dealers. The results of the first campaign show the good enforcement of the farmers. Moreover, the measurement of the water quality seems to put forward a lower impact of these itineraries on water quality. These results are encouraging but need to be checked during the following campaigns.