Impact on Agriculture of the Mount St. Helens Eruptions

• DOI: 10.1126/science.211.4477.16
• Publication Date: 2006-10-05T17:45:58Z
• Authors: R. J. Cook; J. C. Barron; R. I. Papendick; G. J. Williams
• Keywords: Volcanic ash

Ash from Mount St. Helens has fallen over a diverse agricultural area, with deposits of up to 30 kilograms per square meter. Crop losses in eastern Washington are estimated at about $100 million 1980-about 7 percent the normal crop value affected area and less than was expected initially. Production wheat, potatoes, apples will be or above because favorable conditions for growth these crops since ashfall helped offset losses. Alfalfa hay severely lodged under weight ash, but ash-contaminated is apparently nontoxic when eaten by livestock. The ash as an abrasive lethal certain insects, such bees grasshoppers, populations recovering. increased production costs necessitating machinery repairs tillage. On soil, reduces water infiltration, increases surface albedo, may continue affect runoff, erosion, evaporation, soil temperature even tilled into soil. on plant leaves reduced photosynthesis 90 percent. Most plants have tended shed ash. With possible exception sulfur, elements either unavailable present very low concentrations; no significant contribution nutrient status soils expected.