Reducing CO2 Flux by Decreasing Tillage in Ohio: Overcoming Conjecture with Data

Abstract

While the literature is clear about excessive tillage decreasing soil carbon (C) content, there are few experimental studies that document the comparative effects of soil and crop management on C sequestration. Using micrometeorology we measured CO2 flux from a maize crop grown on both no-till and tilled soils in north-central Ohio. We used Bowen Ratio Energy Balance (BREB) systems to quantify the flux between the atmosphere and either the soil surface (at crop planting) or 0.2 m above the canopy once the crop was established and growing. The no-till plot sequestered 263 g CO2 m-2 (90% confidence interval -432.1 to -99.9) while the tilled plot emitted 146 g CO2 m-2 (90% confidence interval -53.3 to 332.2) during 104 days of the 2015 growing season; a net difference of 410 g CO2 m-2. The difference is statistically significant at the 90% confidence level (based on a bootstrap analysis). The results indicate that no-tillage practices can sequester C, maintain soil productivity, and ensure landscape sustainability.