Salvaging Crops After Flood Damage
Seasonal temps play a major role in the effects of flooding on crops, with summer floods generally being more destructive than spring flood events. The warmer summer weather means a much greater chance of damage to submerged plants and crops. In the spring, temps are colder and those same plants can survive longer underwater. Restoration of alfalfa, perennials, and hay often are dependent on these factors, as well as the steps taken toward recovery.
Alfalfa can withstand being submerged for a limited time, up to ten days in dormant plants. It can also recover from silt deposits as long as they are not too severe. In some cases, reworking and reseeding the land may be required.
Irrigated pastures may be restored without serious production losses as long as silt deposits are not over 2 inches. Grasses may also grow through moderate silt deposits, and hold up under several days of flooding with no ill effects. Meadow foxtail and reed canary grass may be able to withstand longer submersion times than perennial grasses.
Some overly mature grasses can be partially salvaged by mixing less mature forage and ensiling the crop. Ensiling is done through the construction of trench silos, locating them in an area where drainage is good, and designing the trench for efficient seeding.
Hay crops may be salvaged by removing old growth from fields that have not been harvested. If the crop is silt damaged, chop it back into the field and topdress with fertilizer. You can check with your county extension agent for additional guidance on specific recommendations for proper topdressing procedures.