Most of the nitrogen in hog lagoons is ammonia. It vaporizes into the air as ammonia gas, and comes back down ready for algae and plant uptake. We exposed the fact that municipal WWTP's were converting their ammonia to nitrate and then dumping it. They will have to upgrade to transform nitrate to the harmless N2 nitrogen gas, a process called denitrification. Little of this is taking place in the large hog operations.
Ammonia losses begin immediately after it leaves the hog.
It continues to volatilize from the lagoons. More is lost during the spray irrigation and then finally after the application. An average hog produces 25.4 lbs nitrogen per year. Some scientist have reported how much volatilizes from a single stage and some the accumulative amounts. While a loss of nitrogen could be bad for the farm if they did not have enough, this is not a high priority with lagoon systems.