Residue and tillage effects on planting implement-induced short-term CO2 and water loss from a loamy sand soil in Alabama

Recent research indicates tillage operations result in a rapid physical release of CO₂ and water vapor from soil. However, effects of soil disturbance on gas fluxes during planting operations have not been adequately explored. Our objective was to measure short-term gas loss resulting from the use of different planting preparation implements on long-term residue-covered soil (no-till) on a Norfolk loamy sand (Typic Kandiudults; FAO classification Luxic Ferralsols) in east-central Alabama, USA. A crimson clover (Trifolium incarnatum L.) cover crop was killed with herbicide two weeks prior to the study. Due to dry soil conditions, 15 mm of water was applied 24 h prior to study. Gas fluxes were measured with a large canopy chamber (centered over two rows) for an integrated assessment of equipment-induced soil disturbance. Increased losses of CO₂ and water vapor were directly related to increases in soil disturbance. Although these short-term C losses are minor in terms of predicting long-term C turnover in agro-ecosystems, results suggest that selecting planting equipment that maintains surface residue and minimizes soil disturbance could help to conserve soil water needed for successful seedling establishment in these coarse textured soils.