Application Technique and Slurry Co‐Fermentation Effects on Ammonia, Nitrous Oxide, and Methane Emissions after Spreading

Abstract

The aim of this study was to investigate the effect of different application techniques on greenhouse gas emission from co-fermented slurry. Ammonia (NH3), nitrous oxide (N2O), and methane (CH4) emissions were measured in two field experiments with four different application techniques on arable and grassland sites. To gather information about fermentation effects, unfermented slurry was also tested, but with trail hose application only. Co-fermented slurry was applied in April at a rate of 30 m3 ha(-1). Measurements were made every 4 h on the first day after application and were continued for 6 wk with gradually decreasing sampling frequency. Methane emissions were <150 g C ha(-1) from co-fermentation products and seemed to result from dissolved CH4. Only in the grassland experiment were emissions from unfermented slurry significantly higher, with wetter weather conditions probably promoting CH4 production. Nitrous oxide emission was significantly increased by injection on arable and grassland sites two- and threefold, respectively. Ammonia emissions were smallest after injection or trail shoe application and are discussed in the preceding paper. We evaluated the climatic relevance of the measured gas emissions from the different application techniques based on the comparison of CO2 equivalents. It was evident that NH3 emission reduction, which can be achieved by injection, is at least compensated by increased N2O emissions. Our results indicate that on arable land, trail hose application with immediate shallow incorporation, and on grassland, trail shoe application, bear the smallest risks of high greenhouse gas emissions when fertilizing with co-fermented slurry.

Greenhouse Gas Emissions from an Irrigated Silt Loam Soil Amended with Anaerobically Digested Dairy Manure

“…The amount of total organic G added each year varied depending on the N content of the materials collected and dry matter percentage of the slurries (Table 1). Similar results of varying G additions have been reported by others (Fangueiro et al, 2008b;Rochette et al, 2006;Wulf et al, 2002). The total organic G added in 2008 was twice that of 2007, averaging 1380 kg G ha"' for LM in 2007 and4295 kg G ha"' in 2008.…”

“…Daily CH^ fluxes among treatments averaged -0.66 g CH^-C ha"' d~' in 2007 and -0.79 g CH^-C ha"' d~' in 2008, exclusive of the period associated with manure amendments. These seasonal uptake rates are lower than some values reported in the literature, with ranges of -6.4 to -13 g m-2 d-' (Phillips et al, 2009;Wulf et al, 2002). Haile-Mariam et al (2008) reported -1.4 g CH^-C ha"' d"' from irrigated soils cropped to potato {Solanum tuberosum L.) or sweet corn during the crop season ( 125 d).…”

“…CH4, and N^O (Johnson and Johnson, 2006;USEPA, 2009). Carbon dioxide is released from manure storage facilities and soils due to microbial decomposition of the organic C contained in the manure (Fangueiro et al, 2008a,b;Chadwick et al, 2000;Wulf et al, 2002). Nitrous oxide is produced from microbial transformations of N in soils and manures and is often enhanced where the available N exceeds plant requirements, especially under wet conditions (Mosier et al, 1991Phillips, 2007;Buchkinaet al, 2010).…”

Relative effects of anaerobically-digested and conventional liquid swine manure, and N fertilizer on crop yield and greenhouse gas emissions

“…The reported effects of manure treatments on nitrous oxide emissions are variable. Some authors reported similar N 2 O emissions from raw compared to anaerobically digested manure [18], others have reported decreased emissions after anaerobic digestion [13,19,20]. Conversely, Chantigny et al [7] reported increased emissions from digested compared to raw liquid swine manure, when the manures were injected into the soil.…”

Farm biogas production in organic agriculture: System implications

“…In general, emissions are lowest when digestates are injected directly into soils. Higher emissions occur with close to the ground spreading techniques like trailing shoe or hose and highest when digestates are applied through splash plate (Wulf et al, 2002;Nkoa, 2013).…”