Sediment and runoff losses from rainfall simulation: Effects of elevated atmospheric CO2 and tillage practice

Authors: Prior, Stephen; Watts, Dexter; Runion, George; ARRIAGA, FRANCISCO - University Of Wisconsin; Torbert Iii, Henry

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2025
Publication Date: 8/12/2025
Citation: Prior, S.A., Watts, D.B., Runion, G.B., Arriaga, F.J., Torbert III, H.A. 2025. Sediment and runoff losses from rainfall simulation: Effects of elevated atmospheric CO2 and tillage practice. Soil and Tillage Research. 255:106799. https://doi.org/10.1016/j.still.2025.106799.
DOI: https://doi.org/10.1016/j.still.2025.106799

Interpretive Summary: Knowledge on how rising atmospheric CO2 concentration will affect runoff aspects in cropping systems is important to identify future beneficial agricultural practices. Over a 10-year study, elevated CO2 increased crop growth and conservation management (no-till with cover crops) increased crop growth resulting in more plant residues on the soil surface. This greatly increased water infiltration which reduced runoff and soil loss. It also reduced loss of soil nutrients in both sediment and runoff water. These results suggest that farmers who practice conservation agriculture may lose less soil to rain-induced erosion and retain healthier soils in a high CO2 world.

Technical Abstract: There is a lack of information regarding how rising atmospheric CO2 concentration will affect runoff aspects in cropping systems. Following a 10-year study, a rainfall simulation examined the impacts of atmospheric CO2 level (ambient and twice ambient) and tillage system (conventional tillage and no-till) on a Decatur silt loam (clayey, kaolinitic, thermic Rhodic Paleudults). Conventional tillage was a sorghum [Sorghum bicolor (L.) Moench.] and soybean [Glycine max (L.) Merr.] rotation using spring tillage and winter fallow, while the no-till system used this same rotation with three rotated cover crops [crimson clover (Trifolium incarnatum L.), sunn hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)]. Elevated atmospheric CO2 led to more residue production in both tillage systems; this effect was greater under no-till conditions. More residue improved water infiltration only in the no-till system. Regardless of CO2 level, sediment loss was lower under no-till and elevated CO2 reduced sediment loss in the conventional tillage system. No-till reduced sediment loss in addition to C, N, and P lost in sediment. No-till also reduced runoff water volume and N and P losses in this runoff. Results indicated that both high CO2 and no-till management increased surface residues that could improve water infiltration, reduce sediment and runoff losses as well as nutrients lost in sediment and runoff water. This study suggests that farmers who practice conservation agriculture are likely to lose less soil and nutrients to rain-induced erosion and that these improvements could be enhanced as the CO2 concentration in the atmosphere continues to rise.