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 rel ease 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 o f different planting preparation implements on long-term residue-covered so il (no-till) on a Norfolk loamy sand (Typic Kandiudults; FAO classification Luxic Ferralsols) in east-central Alabama, USA. A crimson clover (Trifoliu m incarnatum L.) cover crop was killed with herbicide two weeks prior to th e 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 ov er two rows) for an integrated assessment of equipment-induced soil disturb ance. Increased losses of CO2 and water vapor were directly related to incr eases in soil disturbance. Although these short-term C losses are minor in terms of predicting longterm C turnover in agro-ecosystems, results suggest that selecting planting equipment that maintains surface residue and minim izes soil disturbance could help to conserve soil water needed for successf ul seedling establishment in these coarse textured soils. Published by Else vier Science B.V.