In 2019 we began an ecological intensification experiment at WICST, nested within each of the three cash-grain cropping systems (CS1, CS2, CS3). Ecological intensification is an agricultural management approach that seeks to harness natural processes to reduce or eliminate reliance on synthetic inputs (such as N fertilizer), while simultaneously enhancing ecosystem services and maintaining or increasing system productivity. Along these lines, the Ecological Intensification experiment at WICST  seeks to explore how management practices such as cover cropping, reduced tillage, and crop-livestock integration, applied alone or in concert, impact  the soil health, yield, profitability, and cropping system resilience of Midwestern cash-grain systems. The Ecological Intensification experiment is embedded within the much larger core WICST trial in such a way that it allows for comparison between ecologically intensified and historically managed grain cropping systems. The results of this study will help us understand the climate-plus potential of ecologically intensified Midwestern cash-grain systems, providing critical insights to inform producers, policy makers, and future avenues of research.

Why Ecological Intensification?

Corn, soybeans, and small grains dominate the agricultural landscapes of the North Central US. Intensive production of these grain crops often leads to soil degradation, water pollution, and the release of climate warming greenhouse gasses (particularly N2O and CO2). While carbon sequestration in agricultural soils is often promoted as a way to help mitigate climate change and restore soil function, long-term research at WICST has  shown that this is unlikely to occur under current management in the fertile prairie soils (Mollisols) that cover most farmland in the region. In fact, repeated analysis of soil organic carbon (SOC) stocks at WICST over a 30-year period (1989 to 2019) has revealed that despite best management practices, all of the cash-grain cropping systems at WICST have lost significant amounts of soil SOC¹²³.

Cover cropping, reduced tillage, and crop-livestock integration have been promoted as possible solutions to these challenges, but there is confounding evidence which suggests that the answer is likely more complex than simply implementing one of these management practices.  In addition to improving water infiltration and reducing erosion, cover cropping, reduced tillage, and crop-livestock integration aim to increase carbon inputs and tighten nutrient cycles, which are anticipated to improve soil health, reduce GHG emissions, and sequester SOC. However, the efficacy of these management practices towards achieving their sustainability goals is highly variable, and the addition of these practices sometimes has a negative impact on grain yields. The Ecological Intensification Experiment is a long-term commitment to unravel the trajectory, fate, and longevity of carbon accrual in, and the climate mitigation potential of, ecologically intensified Midwestern cash-grain systems.

Ecological Intensification Treatments

How can I learn more about Ecological Intensification at WICST?

To learn more about the Ecological Intensification study or to inquire about participating in the research at WICST, please reach out to Dr. Gregg Sanford (gsanford@wisc.edu).

¹Sanford, G. R., Posner, J. L., Jackson, R. D., Kucharik, C. J., Hedtcke, J. L., & Lin, T. L. (2012). Soil carbon lost from Mollisols of the North Central U.S.A. with 20 years of agricultural best management practices. Agriculture, Ecosystems and Environment, 162, 68–76. https://doi.org/10.1016/j.agee.2012.08.011

² Sanford, G. R. (2014). Perennial Grasslands Are Essential for Long Term SOC Storage in the Mollisols of the North Central USA. In Soil Carbon (pp. 281–288). Springer International Publishing. https://doi.org/10.1007/978-3-319-04084-4_29

³Dietz, C., Ruark, M.D., Jackson, R.D., & Sanford, G.R. Soil carbon maintained by perennial grasslands but lost by field crops over 30 years in a southern Wisconsin Mollisol. In preparation.