Research on Agro-IBIS aims to estimate the ecological and economic benefits of grazing and cover-cropping

Story by Anna Orfanou and Hunter Mackin

Every day, people in the agricultural sector, from farmers to advisers and planners, need to make tough decisions to balance the increasing demand for food, fiber, biofuel, and clean water. These decisions are only getting more complex due to new crop varieties, climate change, shifting markets, government policies, and changing human demands.

Ecosystem simulation models are one type of tool that represent a simplification of our agricultural and environmental system to help us better understand and visualize the interactions between the climate, soil, water, and nutrients in agroecosystems. These models can provide insight into the effectiveness and environmental impact of agricultural practices at the field scale and land management decisions across watersheds and larger regions and help farmers, land managers, and other stakeholders reach environmental and financial sustainability goals.

Agro-IBIS (IBIS standing for Integrated Biosphere Simulator) is one of these tools that includes representations of land surface and soil physics, canopy physiology, terrestrial carbon balance, solute transport, and management practices. Agro-IBIS can simulate the behavior of several plant functional types, including various types of natural vegetation and crop varieties. The differences in physiology and phenology of the plant functional types along with the different responses to management practices and/or stresses determine the canopy and land surface processes of the model.

Agro-IBIS produces a variety of biophysical outputs including crop yield, dry matter productivity, leaf area index, evapotranspiration, and energy fluxes, but can also be linked to economic drivers of land use change to address how policy decisions (e.g., taxation of fertilizer applications or irrigation) might impact food and biofuel production, as well as other ecosystem services like water quality.

Illustration of the Agro-IBIS agroecosystem model grids.

As George E.P. Box famously said, “all models are wrong, but some are useful.” While all models are wrong because they are simulations of reality instead of reality itself, due to advancements in science and technology, models such as Agro-IBIS have become more useful and valuable in recent years as lawmakers and stakeholders attempt to create policy that accounts for the interconnected systems in agricultural landscapes.

The focus of our research with Agro-IBIS on the Grassland 2.0 modeling team is two-fold:

  • exploring how cover crops growing in various cropping systems affect carbon, nitrogen, phosphorus, and water dynamics, and
  • incorporating grazing into the landscape with dials for different management scenarios.

By conducting this research, we hope to develop reliable environmental forecasts for land with cover cropping and grazing. In the process, our simulations will give reasonable estimates of changes in carbon, nitrogen, phosphorus, and water content that would be difficult to obtain with conventional experiments due to time and cost constraints.

Ultimately, we hope our model simulations can more fully include some of the most effective practices regenerative agriculture has to offer and are able to estimate their ecological and economic benefits firsthand. This information will in turn allow producers, advisors, educators and planners to make decisions about what makes the most sense for their land, watershed, or community.

Anna Orfanou, Research Associate, UW-Madison

Anna Orfanou is a Research Associate (Postdoc) in the Jackson Lab, Department of Agronomy at the University of Wisconsin-Madison. Anna received her B.S. in Agricultural Sciences from the University of Thessaly in Greece before obtaining her M.S. in Biosystems Engineering with specialization on Automation and System Technology from Aarhus University in Denmark. Her interest in decision support systems (DSS) and precision agriculture led her to the University of Georgia, where she joined the Georgia Precision Ag team while pursuing her Ph.D. in the Department of Crop and Soil Sciences. The focus of her Ph.D. was the management and simulation of agronomic practices for pursuing high maize yields. Her postdoctoral research focuses on calibrating and validating the Agro-IBIS simulation model to explore how cover crops growing in various cropping systems affect carbon, nitrogen, phosphorus, and water dynamics. Anna’s long term scientific goals are to develop and improve tools that can assist in decision-making processes for the benefit of society.

Hunter Mackin, Ph.D Student, UW-Madison

Hunter Mackin is an Environment and Resources MS/PhD student in the Kucharik lab at the University of Wisconsin-Madison. Hunter received his B.S. in Environmental Science and Economics at the University of Oregon in 2019, where he was involved with research on native prairies and how they relate to current and future environments. Utilizing some modeling experience from economics, he now aims to improve modeling for grasslands more broadly within Agro-IBIS. By incorporating grazing into the model, he seeks to identify best management practices for both the environment into longevity and people economically, while at the same time encouraging animal welfare.