Premium
A Rapid Method for Measuring Feces Ammonia‐Nitrogen and Carbon Dioxide‐Carbon Emissions and Decomposition Rate Constants
Author(s) -
Chang Jiyul,
Clay David E.,
Clay Sharon A.,
Smart Alexander J.,
Ohrtman Michelle K.
Publication year - 2017
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2016.08.0468
Subject(s) - volatilisation , carbon dioxide , ammonia , chemistry , decomposition , environmental chemistry , carbon fibers , nitrogen , ammonia volatilization from urea , environmental science , analytical chemistry (journal) , materials science , organic chemistry , composite number , composite material
Core Ideas Carbon storage and ammonia volatilization from feces can be quantified using techniques described in this article. Carbon dioxide and NH 3 emission follow diurnal cycles and it is difficult to accurately predict CO 2 loss and ammonia volatilization based on point measurements. Conducting rapid assessments that produce definitive findings helps build trust between scientists and and on‐farm producer collaborators.A rapid approach is needed for determining the effectiveness of precision conservation on soil health as evaluated using CO 2 and NH 3 emissions. This study demonstrated an approach for calculating CO 2 –C and NH 3 –N emissions and associated rate constants when feces were applied to bare soil or soil + vegetation. In addition, point CO 2 –C emission measurements were compared with near continuous measurements. The CO 2 –C emissions were measured at 2 h intervals over 20 d, whereas ammonia volatilization was measured three times daily for 7 d. Total CO 2 –C emissions over 20 d were 5% lower [186 g CO 2 –C (m 2 × 20 d) −1 ] than point measurement collected at 1100 h every day (197 g CO 2 –C (m 2 × 20 d) −1 ), and about 10% lower than if collected every 2 d [206 g CO 2 –C (m 2 × 20 d) −1 ]. A Fast Fourier transformation (FFT) showed that temperature and NH 3 –N and CO 2 –C emissions followed diurnal cycles and that they were in‐phase with each other. Over 7 d, 20% of feces NH 4 –N was volatilized and that this loss was similar when feces were applied over vegetation or mixed into the soil. Feces additions increased the amplitude of the CO 2 –C diurnal cycle, and the fecal‐C first‐order rate degradation constants were higher when mixed with soil [0.0109 ± 0.0043 g(g×d) −1 , p = 0.1] than applied over vegetation [0.00454 ± 0.00336 g(g×d) −1 , p = 0.1].