IMPACTS ON AGRICULTURE FOLLOWING THE MAY 2008 CHAITéN ERUPTION IN PATAGONIA

Large explosive volcanic eruptions are expected to cause a range of impacts on primary production. Volcanic products such as pyroclastic flows, lahars and tephra fall can all cause significant impacts on soils, vegetation, animals, water supplies and people. During large explosive eruptions, farms and rural communities many tens to even hundreds of kilometres from the erupting volcano may be impacted, sometimes significantly. Effects can range from being beneficial (for example, by enriching trace elements in soils and pasture) through to extremely severe, for example if farmland has to be abandoned for the foreseeable future.

On 2 May 2008, a rhyolitic eruption from Chaitén volcano in southern Chile led to extensive ashfalls over >200,000 km² of Chile and Argentina. Widespread impacts on agriculture occurred, including burial of pastures and crops leading to farm abandonment in the short term. Livestock deaths occurred where pastures were buried and they could not be evacuated in time. Other impacts on livestock included fungal infections to the skin, and tooth wear from grazing ash-covered feed. However, where <50 mm of ash fell, pasture and crop production reportedly increased, despite concurrent drought. The agricultural emergency response included a successful large-scale livestock evacuation in Chile, with over 10,000 livestock evacuated. Generous government assistance to impacted farmers for livestock losses, feed requirements and to promote cultivation of ash into soil has aided short-term farm recovery.