Performance of bedding materials in affecting ammonia emissions from pig manure

The abilities of different bedding materials to reduce the ammonia emission rate from pig manure and for how long they would be efficient were investigated using an ammonia measuring chamber. Pig manure was treated with straw, straw and peat, straw and Absorbera, straw and PurifiN, and straw and newspaper (3 kg manure with 0.5 kg of bedding material). The ammonia emission rates were measured for a period of 20 min, one day, one week and eight weeks after the application of the bedding materials to the manure samples. No differences in emission rate between the treatments were found one day after the addition of the bedding materials. One week after the addition, manure with straw and PurifiN and manure alone, emitted approximately ten times less ammonia than the other treated manure samples. The treatment with straw and Absorbera resulted in the highest ammonia emission rate, and the treatment ''straw and newspaper'' resulted in a lower ammonia emission rate than the treatment ''straw''. Seven weeks later, manure with straw and PurifiN and manure alone emitted approximately 15 times and nine times more ammonia than the other treated manure samples, respectively. The ammonia emission rates were found to be correlated or slightly correlated with the pH values in the manure samples on all three measuring occasions (R(2) = 0.62, 0.88 and 0.68). The results of the investigation indicated that not only the C/N ratio of a bedding material is important in controlling ammonia emission from manure, but also the availability of the carbon and the structure of the bedding material. Unfortunately, no conclusions can be drawn regarding the overall amounts of ammonia released in the different treatments. (C) 1996 Silsoe Research Institute