When manure is stored, nitrogen escapes through a process called volatilization. This loss of nitrogen through ammonia emissions not only leads to manure odors, but it changes the balance of nitrogen and phosphorus in the manure and that limits the amount of manure you can apply to crops. However, researchers at the USDA’s Agriculture Research Service have discovered a way to reduce nitrogen losses by up to 60 percent.

Treating manure slurry with alum, an acidifying agent, or zeolite, a sequestering agent commonly used in cat litter, reduces the formation of ammonia emissions by 60 percent and 55 percent respectively. This reduction in ammonia emissions reduces nitrogen loss and helps maintain the nitrogen to phosphorus ratio at a level that is more suitable for crops.

Researchers at the ARS Animal and Natural Resources Institute in Beltsville, Md., say the treatments are safe, and cost-effective. The estimated cost of alum, added at a rate of 2.5 percent of the wet weight of manure slurry, was about 50 cents per lactating cow per day. Zeolite was applied at a rate of 6.25 percent of wet weight of manure slurry and carries a similar cost.

ARS News Service