Gaseous Emission and Changes in Nutrient Composition During Deep Litter Composting

Composting of deep litter during storage may cause emission losses of ammonia (NH 3 ), nitrous oxide (N 2 O) and methane (CH 4 ). Emissions of NH 3 , N 2 O and CH 4 from deep litter compost were measured using a dynamic chamber over a period of 57 days from 2 July to 26 August 1997. High concentrations of N 2 O inside the compost heap were found initially and after 20 days of composting. Methane concentrations in the heap were high during days 8-15. As a result of NH 3 volatilization, 2.2 kg NH 3 -N t -1 (23% of total N) was lost in the first 5 days. Emissions of N 2 O amounted to 0.22% of the total N present at the start of the experiment and CH 4 emission represented 0.01% of total C. In this experiment no leaching occurred, and thus non-volatile nutrients were conserved during composting. The population of nitrifying bacteria remained low throughout the experiment (around 105 cells g -1 dry matter) and the density of denitrifying bacteria stayed high (4.2 2 107 cells g -1 dry matter).

Keywords:

• Key Words
• Ammonia Volatilization
• Greenhouse Gas
• Mass Balance
• Wind Rows