No-till farming and greenhouse gas fluxes: Insights from literature and experimental data

• Published in: Soil & tillage research 2022-06, Vol.220, p.105359, Article 105359
• Main Authors: Ruis, S.J., Blanco-Canqui, H., Jasa, P.J., Jin, V.L.
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Corn-soybean; Nitrous oxide; No-till; Plow
• ISSN: 0167-1987; 1879-3444
• DOI: 10.1016/j.still.2022.105359

Tillage intensity may differently impact gaseous losses of C and N to the atmosphere, but data from long-term experiments are relatively few. Yet, this information is needed to better understand C and N losses and gains in agricultural systems. The objective of this study was to determine how tillage intensity affects soil greenhouse gas (GHG) fluxes (CO2, N2O, and CH4) by comparing experimental data from moldboard plow (MP), chisel plow (CP), double disk (DD), and no-till (NT) soils after 38–40 yr of management in a rainfed corn (Zea mays L.)- soybean (Glycine max (L.) Merr) cropping system. We also reviewed global literature to evaluate the impacts of tillage on soil GHG emissions. After 38–40 yr of management, CO2 fluxes decreased in this order: MP > CP ≈ DD > NT, indicating that as tillage intensity decreased, CO2 fluxes decreased. Indeed, daily CO2 fluxes were typically lower under NT than under MP and CP. Similarly, the overall cumulative CO2 fluxes across 26-mo of measurement were 1.4–1.8 times lower with NT than MP, CP, and DD soils. Also, MP soils had 1.3 times higher CO2 fluxes than CP and DD soils. These results are similar to those from our global literature review of 60 studies on CO2 fluxes. The reduction in CO2 fluxes in NT was likely due to a combination of increased residue cover, reduced soil temperature (r = 0.71; n = 12; p no-till after 40 yr.•Fluxes of CO2 decreased as tillage intensity decreased.•Tillage systems had minimal effects on N2O and CH4 fluxes.•No-till farming is the top option to mitigate soil C losses as CO2.