Rainfall also washes gaseous ammonia back to the ground surface. In general, weather that is most conducive to hay drying would also maximize N losses from surface-applied manure. In addition, high initial soil moisture further enhances ammonia release. However, using application equipment on excessively wet soils should be avoided because of potential soil compaction and structural degradation. Percent of nitrogen applied that is lost within four days of application.
Anaerobic treatment is the breakdown of manure organic matter in an oxygen-free environment.
Nearly all deep, unagitated, liquid or slurry manure storage structures function anaerobically at least part of the time. In winter months, when microbial activity is low, little N is released. However, from June to late October, bacteria thrive and volatilization increases.