Abstract

As a result of the free trade agreements signed by Chile, which will open markets for the export of dairy and beef products, it is expected that the livestock production activity will be increased and intensified in Southern Chile. Despite the technological knowledge available for livestock production in the area, little is known about the environmental impact of this activity, especially on surface waters, in spite of the fact that the rivers and lakes of the region are also the main resources for other important economic activities, such as aquaculture and tourism. In developed countries it has been shown that there is a strong cause-effect relationship between livestock production and diffuse pollution of surface waters, especially in relation to the eutrophication of these resources, because of high nitrogen (N) and phosphorous (P) concentrations. If an analysis of the mechanisms controlling N and P losses from livestock systems to waters is made, it is possible to develop a possible scenario for the Lake District of Southern Chile. The greater number of inputs, the use of increasing stocking rates, the lack of best management practices and the incorporation of hilly areas or where artificial drainage has been incorporated, will probably result in low efficiency in the use of both the N and P incorporated into the livestock systems as fertilizers, increasing their losses, and in turn resulting in the eutrophication of nearby water resources.