A low cost solution for ammonia emission abatement from slurry storage

A Leca® balls layer was evaluated for its ability to reduce losses of ammonia from the liquid surface of stored swine manure. An uncovered slurry tank partly embedded in the ground was divided into two halves by a plastic sheet. A 10 cm thick Leca® balls layer was applied to the surface of one half of the slurry tank. Ammonia emission was measured by means of the funnel technique floating on the slurry surface. Ammonia emitted from the Leca® balls covered and uncovered slurry, respectively, was measured simultaneously over time periods of 24 h for 6 consecutive days. Measurements were repeated in each of the four seasons during 1 year. Ammonia emission from the uncovered slurry ranged between 0.98 and 2.68 gNH3/m2, whereas from the surface covered with Leca® between 0.25 and 0.35 gNH3/m2 were emitted. Results pointed out a significant reduction of ammonia emission (up to 87%) due to the Leca® balls layer, what showed the persistency of this strategy for the whole time period of the trial. A first economic evaluation showed that Leca® results in an increase in slurry management costs of up to 4 Eurocent/m2.