Field scale measurement of greenhouse gas emissions from land applied swine manure

Greenhouse gas emissions (GHGs) from swine production systems are relatively well researched with the exception of emissions from land application of manure. GHGs inventories are needed for process-based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, fall and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used for flux measurement along with gas analysis on a GC-FID-ECD. Measured gas concentrations were used to estimate GHGs flux using four different models: linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier (HMR) model, respectively for comparisons. Cumulative flux estimates after manure application of 5.85 × 105 g•ha–1 (1 ha = 0.01 km2) of CO2, 6.60 × 101 g•ha–1 of CH4, and 3.48 × 103 g•ha–1 N2O for the fall trial and 3.11 × 106 g•ha–1 of CO2, 2.95 × 103 g•ha–1 of CH4, and 1.47 × 104 g•ha–1 N2O after the spring reapplication trial were observed. The N2O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.