While the P and K levels in slurry are relatively stable, N levels are changeable. Urea is the main form of N in fresh slurry. Urea is rapidly converted to ammonia, which is a volatile form of N and easily lost to the atmosphere. In oxygenated conditions, ammonia is converted to nitrate, a less volatile form of N. Slurry is an anaerobic environment, which slows the conversion of ammonia to nitrate and encourages the buildup of ammonia. Grennans Slurry Boost composts your slurry, which reduces ammonia N losses by facilitating a quick conversion from ammonia to nitrate.