To decrease negative environmental impacts associated with row crop agriculture, the conversion of conventional agricultural lands to no-till with cover crops or to restored prairie in the Midwest U.S. has been proposed and has the potential to alter hydrologic behavior. Our understanding of the impacts of this conversion on water and carbon fluxes from (agro-)ecosystems, however, is limited. We deployed eddy covariance systems in a business-as-usual (BAU) tilled cropping system, an aspirational (ASP) no-till cropping system with cover crops, and a native tallgrass prairie (TP) ecosystem to measure evapotranspiration (ET) and carbon dioxide exchange with the atmosphere. Measurements began in 2015 and we have at least 4 complete years of observations at each site. The average annual ET is higher at the TP site than the BAU site, but not significantly different from the ASP site. The gross primary production and ecosystem respiration are highest at the ASP site. Average annual net ecosystem exchange is negative (carbon uptake) at both agricultural sites (-305 ± 25 and -311 ± 31 gC m-2 yr-1 at ASP and BAU, respectively) and neutral in the prairie (-11 ± 10 gC m-2 yr-1 at TP). We evaluate the sensitivity of fluxes to environmental conditions including soil water content, vapor pressure deficit, air temperature, and photosynthetic photon flux density and find that the BAU site is the most sensitive to changes in environmental conditions while the TP site is the most resilient to changes. The interannual variability in ET is accentuated by agricultural management and because of the more diverse cropping system, is highest at the ASP site. The interannual variability in carbon fluxes, however, is not increased by agricultural management. Our findings illustrate how conservation practices impact the water budget and highlights the value of these practices in a changing climate.
