Received: 13 Apr 2015 – Discussion started: 20 May 2015 – Revised: 08 Feb 2016 – Accepted: 14 Feb 2016 – Published: 02 Mar 2016
Abstract. Nitrogen isotope ratios (δ15N) of NH4+ in dairy manure compost piles with and without bulking agent (10 % w∕w) were compared to understand the effects of the use of bulking agent on nitrogen conversion during manure composting. The δ15N–NH4+ values in each of three pile zones (top, side and core) were also compared. At the end of the process, piles with bulking agent showed significantly higher δ15N values (17.7 ± 1.3 ‰) than piles without bulking agent (11.8 ± 0.9 ‰), reflecting the significantly higher nitrogen conversion and NH3 loss in the former. The samples from the top zone, especially in the piles with bulking agent, showed very high NH4+ concentrations with significantly high 15N (δ15N: 12.7–29.8 ‰) values, indicating that extremely high nitrogen conversion, nitrification–denitrification activity of the microbes and NH3 volatilization occurred in this zone.
Nitrogen isotope ratios (δ15N) of NH4+ in dairy manure compost piles were studied. The δ15N–NH4+ values in different pile zones (top, side and core) show that extremely high nitrogen conversion, nitrification–denitrification activity of the microbes and NH3 volatilization occurred in pile top zone, which has very high NH4+ concentrations and significantly high 15N (δ15N: 12.7–29.8 ‰) values.
Nitrogen isotope ratios (δ15N) of NH4+ in dairy manure compost piles were studied. The...