Effect of cattle slurry application techniques on N₂O and NH₃ emissions from a loamy soil

Abstract

We determined N2O fluxes from an unfertilized control (CON), from a treatment with mineral N‐fertilizer (MIN), from cattle slurry with banded surface application and subsequent incorporation (INC), and from slurry injection (INJ) to silage maize (Zea mays, L.) on a Haplic Luvisol in southwest Germany. In both years, amount of available N (total N fertilized + Nmin content before N application) was 210 kg N ha−1. In the slurry treatment of the 1st year, 140 kg N ha−1 were either injected or incorporated, whereas 30 kg N ha−1 were surface applied to avoid destruction of the maize plants. In the 2nd year, all fertilizers were applied with one single application. We calculated greenhouse gas emissions (GHG) on field level including direct N2O emissions (calculated from the measured flux rates), indirect N2O emissions (NH3 and NO3 - induced N2O emission), net CH4 fluxes, fuel consumption and pre‐chain emissions from mineral fertilizer. NH3 losses were measured in the 2nd year using the Dräger‐Tube Method and estimated for both years. NH3 emission was highest in the treatment without incorporation. It generally contributed less than 5% of the greenhouse gas (GHG) emission from silage maize cultivation. The mean area‐related N2O emission, determined with the closed chamber method was 2.8, 4.7, 4.4 and 13.8 kg N2O‐N ha−1 y−1 for CON, MIN, INC, and INJ, respectively. Yield‐related N2O emission showed the same trend. Across all treatments, direct N2O emission was the major contributor to GHG with an average of 79%. Trail hose application with immediate incorporation was found to be the optimum management practice for livestock farmers in our study region.

Field Application of Organic Fertilizers Triggers N2O Emissions From the Soil N Pool as Indicated by 15N-Labeled Digestates

“…The high temporal variability of N 2 O fluxes in this study, with increased flux rates after application of crop residues or organic fertilizers and after rainfall events, was similarly documented in other experiments (Pfab et al, 2012;Herr et al, 2019). Ultimately, N 2 O fluxes leveled off 30 days after digestate application in both years with drying of the soil during warm periods with low rainfall.…”

“…In a field study, NH + 4 -N-labeled cattle slurry was applied, which produced higher fertilizer-derived N 2 O emissions within the first 10 days, but higher soil-derived N 2 O 11-22 days after application (Dittert et al, 2001). However, the study was carried out on grassland and using the injection technique (Dittert et al, 2001), which has been reported to increase N 2 O emissions compared to trail hose application with immediate incorporation (Herr et al, 2019).…”

“…The largest share of N 2 O release during the growing season usually occurs shortly after field application, with further peaks correlated to rainfall-events (Guzman-Bustamante et al, 2019;Herr et al, 2019) or freeze-thaw periods Rochette et al, 2008 We cut the ryegrass three times in 30-days intervals. Sugar beet was grown in Mitscherlich pots with 12 kg sand.…”

Effect of Nitrification Inhibitors on N2O Emissions after Cattle Slurry Application

“…In contrast to the beneficial reduction of NH 3 losses, slurry INJ can promote anaerobic conditions in the injection slot and thus stimulates N 2 O release from denitrification [17,18]. The high N 2 O emission after cattle slurry INJ can even exceed the NH 3 loss following slurry INC with a disc harrow two hours after broadcast application [19].…”

Aerated Buffalo Slurry Improves Spinach Plant Growth and Mitigates CO2 and N2O Emissions from Soil

“…In the last decade, many studies have been carried out in order to find innovative solutions able to mitigate the impact of livestock farming on GHG emissions, including covering slurry tanks, manure composting, acidification, anaerobic digestion, solid-liquid separation, dilution, and slurry aeration [1,2]. Other practices concern waste disposal on the field such as the addition of chemical additives [3] and the injection of slurry into the soil [4]. Aeration is an alternative practice to treat slurry.…”