Articles | Volume 13, issue 4
https://doi.org/10.5194/bg-13-1341-2016
https://doi.org/10.5194/bg-13-1341-2016
Research article
 | 
02 Mar 2016
Research article |  | 02 Mar 2016

Isotopically enriched ammonium shows high nitrogen transformation in the pile top zone of dairy manure compost

Koki Maeda, Sakae Toyoda, Midori Yano, Shohei Hattori, Makoto Fukasawa, Keiichi Nakajima, and Naohiro Yoshida

Abstract. Nitrogen isotope ratios (δ15N) of NH4+ in dairy manure compost piles with and without bulking agent (10 % ww) 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.

Download
Short summary
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.
Altmetrics
Final-revised paper
Preprint