Paracoprid dung beetles and gaseous loss of nitrogen from cow dung

The estimated gaseous loss of nitrogen from cow dung during 4 weeks was almost unaffected by the activity of the dung beetle, Onthophagus lenzii H. The loss of gaseous N was the result primarily of NH3 volatilization during the first week. However, the beetles had a negative effect on NH3 volatilization by lowering the pH and the NH4+-N concentration in colonized cow dung and dung balls. Once NH3 volatilization had ceased, denitrification became prominent and was the cause of 23.6% or more of the loss of N from the dung balls. N2-fixation (acetylene reduction assay) had only a negligible role in the estimated N balance. Denitrifying activity was limited by a deficiency in available endogenous NO3−-N. The action of dung beetles altered environmental conditions and increased ammonification, nitrification and denitrification, as well as N2-fixation.