There are reports of corn injury from anhydrous ammonia burning roots. During cool, dry spring conditions, there is typically injury in some fields. Sometimes this can be from shallow ammonia placement, planting too soon after ammonia application, dry soils allow ammonia to move upward, combination of starter fertilizers with ammonia causing injury and improper sealing of ammonia application zone.

Cool dry weather conditions are the highest risk as wet moist conditions allow ammonia to dilute and lessen the probability of injury.  Injury may cause uneven emergence or slow growing plants. In wetter springs, bands of fertilizers and ammonia will be more diluted as roots grow into the band.

Corn roots will take on a brown appearance or turn dark brown and resemble as if they were burned. Injured plants look drought stricken with tight whorls and if injury is severe, the result is death of plants. Corn seed planted in ammonia may fail to emerge. Also, if corn is planted at an angle to ammonia application, the field may have a checkerboard appearance of missing plants where they were planted over the ammonia.

Wayne Flanary, Field Specialist in Agronomy, University of Missouri Extension has observed injury to corn with pop-up fertilizers: fertilizers that are directly applied to the seed. This combined with ammonia can lead to increased loss of plants.

Proper rainfall will help plants, if they survive, to recover. If plants roots can get established outside of the ammonia zone, it may lead to corn recovery.

For more information, contact Wayne at 816-279-1691.