Ashfall can have significant impacts on crops much like pasture land. Physical impacts from additional weight of ash on leaves, partial burial and stem/branch snapping all prevent the plants natural processes such as photosynthesis, transpiration and water content leading to crop failure (Neild et al., 1998).
Rainfall interacting with volcanic gas within the ash plume may produce acids that fall as acid rain. Continued degassing at the vent may lead to ongoing acid rain even after ashfall ceases. Acid raining falling on plants can lead to both issues for the plant surface, but also hydration issues if absorbed through the soils.
Ash deposited on the ground can also cause also alter soil chemistry, altering the acidity, nutrient content and water content. Changes to these can all detriment the crop survival (Wilson, 2009).Impacts to arable crops are dependent on: