Chamber-based flux measurements were conducted to quantify greenhouse gas (GHG) emissions from agricultural systems. A closed static chamber system was used, consisting of permanently installed bases (50 × 50 cm) inserted approximately 5 cm into the soil and detachable chambers of varying heights to accommodate crop growth. During each sampling event, the chamber was placed on the base and sealed using a water-filled groove to minimize gas leakage. Headspace gas samples were collected at fixed intervals (0, 15, and 30 min after chamber closure) using pre-evacuated gas sampling bags connected to a portable pump. The collected samples were subsequently analyzed using a Picarro G2508 cavity ring-down spectrometer for simultaneous determination of CO₂, CH₄, and N₂O concentrations. Gas fluxes were calculated from the linear change in headspace concentration over time and corrected for chamber volume, surface area, air temperature, and atmospheric pressure. Measurements were conducted regularly throughout the cropping season to characterize temporal variations in GHG fluxes under different agricultural management practices.

Field observations were conducted at a landfill site using complementary eddy covariance (EC) and chamber-based techniques to characterize greenhouse gas emissions, particularly CO₂ and CH₄. The eddy covariance system provides continuous, high-frequency measurements of ecosystem-scale gas exchange over a relatively large upwind footprint, enabling evaluation of temporal variations in landfill GHG emissions and their responses to meteorological conditions such as wind, temperature, and atmospheric turbulence. In contrast, chamber measurements provide plot-scale observations at multiple locations across the landfill surface, allowing the identification of spatial variability, localized emission hotspots, and differences associated with surface conditions.