Soil, slurry and application effects on greenhouse gas emissions

Abstract

In conjunction with soil type and climate, the use of nitrogen fertilizers is a major factor affecting nitrous oxide emissions. This study compares injection of pig slurry and pig slurry digestate at 15 or 20 cm depths with trailing-hose application followed by immediate incorporation. The work was based on a laboratory microcosm experiment with undisturbed soil cylinders (0–30 cm depth) from three arable soils (Histosol, Gleysol and Plaggic Anthrosol). Soil cylinders were fertilized with pig slurry and pig slurry digestate (150 kg N/ha) and emissions of N2O, CH4 and CO2 were monitored. The comparison of application techniques over a 37-day period show that soil type and application technique, had a strong (P < 0.001) impact on N2O emissions. Fertilization with pig slurry showed no significantly higher N2O emissions than pig slurry digestate. Fertilizer injection significantly increased N2O emissions compared to fertilization with a trailing-hose with incorporation.