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Nitrous Oxide Emitted from Soil Receiving Anaerobically Digested Solid Cattle Manure
Author(s) -
Thomas Ben W.,
Hao Xiying
Publication year - 2017
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2017.02.0044
Subject(s) - digestate , manure , biogas , agronomy , nitrous oxide , anaerobic digestion , manure management , environmental science , hordeum vulgare , total dissolved solids , volatilisation , chemistry , zoology , environmental engineering , waste management , poaceae , methane , biology , organic chemistry , engineering
Limited information is available about soil nitrous oxide (N 2 O) fluxes, N 2 O emission factors (EFs), and yield‐scaled N 2 O emissions for biogas residues used to fertilize crops in semiarid regions. To address this knowledge gap, a 4‐yr field experiment was conducted in a semiarid climate to determine growing season N 2 O fluxes from soil receiving (i) anaerobically digested solid beef cattle manure (digestate), (ii) separated solids from the digestate (separated solids), and (iii) undigested solid beef cattle manure (cattle manure) applied to target one and two times the recommended rates (200 and 400 kg total N ha −1 ) for barley ( Hordeum vulgare L.) forage, assuming 50% of N was annually plant available. Nitrous oxide fluxes were determined using vented static chambers. Over the four growing seasons, 95, 80, and 81% of the N 2 O flux occurred within 36 d of applying digestate, separated solids, and cattle manure, respectively. The cumulative N 2 O emissions with digestate were 4.7 and 4.1 times the values of the separated solids and cattle manure, respectively. The digestate N 2 O EF was 13.6 and 10.6 times the values of the separated solids and cattle manure, respectively, but the N 2 O EF based on applied mineral N was similar for all amendments. The yield‐scaled N 2 O emissions with digestate were 4.3 and 3.6 times the values of the separated solids and cattle manure, respectively. In the semiarid region of southern Alberta, liquid biogas residues have a higher risk for N 2 O emissions than both the separated solid fraction of the biogas residues and undigested cattle manure. Core Ideas Information on N 2 O emitted from biogas residues applied to semiarid soils is limited. 80 to 95% of N 2 O emissions occurred within 36 d of amendment application over 4 yr. Digestate led to 4.4 times the N 2 O emissions of separated solids and cattle manure. Digestate had 10.6 to 13.6 times the N 2 O emission factors of separated solids and cattle manure. Digestate had 4.0 times the yield‐scaled N 2 O of separated solids and cattle manure.