Soil Carbon Dioxide Fluxes in Conventional and Conservation Tillage Corn Production Systems Receiving Poultry Litter and Inorganic Fertilizer

Abstract

Soil management practices can alter the natural balance at the soil-plant-atmosphere ecosystem interface, which can significantly affect the environment. This study compared CO₂ fluxes in conventional tillage (CT) and no-tillage (NT) corn (Zea mays L.) production systems receiving poultry litter (PL) and ammonium nitrate (AN) fertilizers on a Decatur silt loam soil in the Tennessee Valley region of North Alabama from Spring 2008 to Fall 2009. Soil CO₂ flux in CT plots (9.5 kg CO₂ ha⁻¹ day⁻¹) was significantly greater than that in NT plots (4.9 kg CO₂ ha⁻¹ day⁻¹ in summer. Soil CO₂ fluxes were lowest in fall where CT plots had a mean soil CO₂ emission of 0.8 kg CO₂ ha⁻¹ day⁻¹, while plots under NT and grass fallow system were sinks of CO₂ with fluxes −0.6 and −1.0 kg CO₂ ha⁻¹ day⁻¹, respectively. Mean soil CO₂ flux averaged over seasons in NT plots was 36% lower than that in CT plots. Grass fallow plots were net sinks of CO₂ with a mean CO₂ flux of −0.4 kg CO₂ ha⁻¹ day⁻¹. Our study showed that application of PL or AN fertilizer in NT systems can significantly reduce soil CO₂ emissions compared to CT systems in corn production.

Keywords:

• carbon dioxide flux
• conservation tillage
• greenhouse gases
• no-tillage
• poultry litter