Mapping the current extent and suitability of agroforestry in the US Midwest

US Midwest Agroforestry Suitability Map

Agroforestry had the highest overall social-ecological suitability throughout much of Missouri, south-central Iowa, western Nebraska, eastern Kansas, southeastern Wisconsin, and eastern Ohio through southern Indiana and Illinois. Western Nebraska had fewer identified opportunities for riparian buffers due to fewer surface water bodies. Spatial patterns shifted somewhat when environmental priority areas were weighted similarly to the combined social and economic criteria (i.e., by multiplying the environmental priorities layer by two before adding with the social and economic layers) instead of weighing all three layers equally).

Comparing environmental-only suitability maps with overall social-ecological suitability maps, the target areas for agroforestry also shift considerably. Some areas with high opportunities to use agroforestry to address environmental concerns may have implementation challenges due to social, economic, and tree growth constraints. Specific examples include central Illinois, central and northern Iowa, and northern Indiana.

We extracted the areas identified as the top 5% of lands most suitable for agroforestry for each of the four agroforestry practices to estimate the potential carbon storage contributions of converting those lands to agroforestry practices using the COMET-Planner tool. Results show that an agroforestry transition to these lands best suited for agroforestry based on our criteria (totaling 23.6 million acres) has the potential to store 43 [29-58] megatonnes of CO₂ per year.  We also find that such a transition would store considerably more carbon than a transition to cover cropping. If the same lands were transitioned to cover crops with a 25-50% reduction in fertilizer N, approximately 8.4 [-2.3-23.6] megatonnes CO2 eq./year would be stored, or some five times less than agroforestry.

While we procured some expert input on the selection and weighting of criteria, the priorities may shift between users and over time. Accordingly, we translated our model into a publicly available decision-support tool as a Google Earth Engine app, currently in beta testing, available at the following link: https://agroforestrymap.projects.earthengine.app/view/agroforestry-suitability-tool. The tool allows users to define which criteria to use, weigh them according to their own priorities, and select their scale of analysis (Midwest, state, county, or watershed). It also allows users to explore in the results in high resolution for planning. Users can also view the layers that make up the overall suitability map, visualizing: environmental priority areas, tree growth suitability, economic viability, and social feasibility.

Agroforestry in Illinois

Suitability map

Agroforestry was determined to have the highest suitability throughout southern and western Illinois when using the full social and environmental criteria. When considering only the potential of agroforestry to address environmental goals, central and northern Illinois had higher potential for expanding agroforestry, though we expect that the ability to competitively grow diverse agroforestry species and gain social acceptability would be more challenging in these regions. The shifted priorities from including the socioeconomic dimensions of agroforestry’s suitability reflected the expert expectations conveyed during key informant interviews with Midwestern agroforestry experts. We explore these themes further through formal, semi-structured interviews with producers and program administrators throughout Illinois. Additionally, we found that there are large carbon storage potential benefits through expanding agroforestry on highly suitable Illinois lands. We also identified thousands of acres with potential suitability for agroforestry in terms of environmental objectives, tree growth requirements, and social feasibility that were estimated to be marginal (low crop value) lands. 

We used a qualitative research approach to examine the opportunities and barriers to agroforestry adoption as well as the relative importance of environmental, social, and economic criteria within interviewees’ decision-making processes. The fieldwork consisted of individual in-person or virtual interviews with a diverse set of farmers and ranchers in Illinois (Table 1). We also interviewed program administrators within governmental and non-governmental organizations (e.g., Farm Service Agency, USDA Natural Resource Conservation Service, USDA Forest Service, and university extension) to understand their perspectives on the policy landscape of agroforestry in the US Midwest. Farmers and ranchers were recruited from southern, central, and northern Illinois, and program administrators were recruited primarily from Illinois but also from among those based elsewhere in the Midwest but with knowledge relevant to Illinois.

Table 1: Summary table of the number and types of interviewees

Table 1 Notes:

* One conventional farmer was maintaining their windbreaks and riparian buffers, but they did not intentionally plant or harvest them. We interviewed an eighth conventional farmer; their data has not yet been analyzed.

** Three program administrators were also producers. We analyzed their responses primarily as producers, but their broader responses concerning policy and working with other producers were also analyzed. 

Through the semi-structured interviews, we found that overall, there was some misalignment between the perceived value of agroforestry and the individual values held by farmers in Illinois, particularly with the values farmers prioritized in their adoption decision-making. While the early adopters of agroforestry, along with many of the program administrators, viewed agroforestry as a potential opportunity for production and profitability, non-adopters tended to view agroforestry as strictly taking land out of production for conservation. The early adopters were willing to seek out relevant resources and information, take financial risk with the expectation of long-term gain, and be creative in finding near-term solutions. We found that the primary motivations that farmers had for adopting agroforestry were relational values: helping their community, working in harmony with nature, and enjoyment in farming. There were also strong non-material values in terms of supporting a stewardship identity and creating farming systems that provide sustainable options for the current and future generations. While most adopters shared appreciation for the numerous regulating and intrinsic values of agroforestry that they perceived, these were often not the primary motivators of their adoption decisions, except for those who had adopted partial-farm agroforestry to reduce problems with soil erosion.

Table 2: Number of interviewees mentioning their positive, negative, and neutral perceptions of agroforestry’s value to deliver intrinsic, instrumental, and relational outcomes. Green cells indicate a relatively higher number of mentions and yellow cells indicate a relatively lower number of mentions.

¹Includes the economic value of the material goods

We found that overall, there was some misalignment between the perceived value of agroforestry and the individual values held by farmers in Illinois, particularly with the values farmers prioritized in their adoption decision-making. While the early adopters of agroforestry, along with many of the program administrators, viewed agroforestry as a potential opportunity for production and profitability, non-adopters tended to view agroforestry as strictly taking land out of production for conservation. The early adopters were willing to seek out relevant resources and information, take financial risks with the expectation of long-term gain, and be creative in finding near-term solutions. Key opportunities for expanding agroforestry included: (1) developing demonstration farm networks to both visualize agroforestry within the landscape and conduct research on economics and management, (2) providing sufficient conservation practice incentives with pricing to match rental rates into the long-term (e.g., beyond the typical 10-year CRP contract), and (3) improving education and messaging by linking the potential benefits of agroforestry to farmers’ goals.

We identified numerous barriers to agroforestry adoption as well as opportunities for overcoming some of those barriers. Most of the barriers were directly related to socioeconomics and crop production: tenure security, temporal gap between investment and revenue, lack of funding, negative tree-crop interactions, and equipment challenges. Two of the primary proposed solutions for addressing these barriers were establishing a demonstration farm network, with economic assessments, as well as providing markets and market resources for selling agroforestry products. These demonstration farms and research could be essential to overcome the current social norms and the view of agroforestry as an unproductive conservation practice that is not worth establishing or managing. Additionally, greater technical support and the expansion of farmer-to-farmer networks to share knowledge and resources could help overcome these barriers.

Agroforestry adopters and conservation program administrators typically had very positive responses to an agroforestry transition using a scenario of 5-10% of land being converted to agroforestry. They viewed such a transition as helping to improve regulating services and quality of life. However, all types of interviewees had concerns that a transition to expanding agroforestry would be met with substantial social and economic barriers. Most of the stakeholders we interviewed expected that there would be substantial social resistance to agroforestry after decades of social norms pushing farmers to remove trees to keep a “tidy” farm with maximum productivity. However, almost everyone we spoke with recognized potential gains to ecosystem services and nature through agroforestry. Overall, there was a perceived potential for expanding agroforestry in Illinois through designing stable, flexible, and appropriate incentive programs coupled with extensive outreach, education, and training to demonstrate the viability and opportunity of agroforestry.