The steady flow of wet weather in April caused many Kentucky producers to worry about nitrogen losses in their fields, especially in fields where nitrogen applications were made prior to the rains.

Fortunately, nitrogen losses may not be as bad as many producers expect, said Lloyd Murdock, Extension soils specialist with the University of Kentucky College of Agriculture.

“Producers always expect high nitrogen losses during extremely wet conditions,” Murdock said. “In most cases, they aren’t going to have the losses they anticipated. Not knowing this could cause them to spend an excessive amount of money on additional fertilizers.”

Producers who farm areas that annually flood, such as along the Mississippi and Ohio rivers, typically haven’t applied nitrogen yet. Those who farm along creeks and secondary rivers, however, may have already applied nitrogen. These areas may be submerged for some time as the smaller tributaries will be backed up due to major flooding of the larger rivers.

The main cause of nitrogen loss in wet soils is denitrification. This occurs when bacteria convert the nitrate nitrogen in the soil into nitrogen gas. Denitrification is triggered when the soil remains saturated for two to three days. Poorly drained, low-lying areas are the most susceptible.