Methane emissions from an anaerobic swine lagoon

Gaseous methane (CH4) emissions from a swine waste holding lagoon were determined periodically during the year. Micrometeorological techniques were used in order that emission rates from the lagoon were measured under ambient conditions with little disturbance to the natural environment. During the cold winter measurement period, CH4 fluxes were linearly related to lagoon water temperature below 22°C (r=0.87). During warmer measurement periods, both water and air temperatures and windspeed affected emissions rates. In general, flux rates followed a diurnal pattern with greater fluxes during the day when both temperature and windspeed were greatest. Mathematical models using air and water temperature and windspeed factors could explain 47 to 75% of the variation in fluxes. Daily emission rates ranged from 1 to 500 kg CH4 ha−1 d−1. The average flux for the year was 52.3 kg CH4 ha−1 d−1 which corresponded to about 5.6 kg CH4 animal−1 yr−1 from the primary lagoon.