Would fallout permanently affect pasture grass and forage crops?
If fallout is extremely light, the pasture would be usable immediately. It is difficult to set an exact external dose rate at which it would be safe to return the animals to pasture, but if the dose for the first week of stay did not exceed 25 roentgens all animals would survive and could be handled with safety. If fallout is heavy, external radiation would prohibit use of the pasture. A heavy deposit of fallout would spread short-lived and long-lived radioactive particles on the pasture and forage crops. Radiation might cause visible injury to plants. Some plants might die. Existing growths of alfalfa and other forage crops might not be usable because of radiation hazard. If a radiation survey should indicate that contamination level is high, existing growth should be removed as close to the ground as possible and discarded; succeeding growths should be used only after examination for radioactivity. If the soil is acid, a top-dressing of lime would help reduce uptake of radioactive st
