Yield, growth, and labor demands of growing maize, beans, and squash in monoculture versus the Three Sisters

Societal Impact Statement Intercropping techniques like the Three Sisters, where maize, beans, and squash are grown in an intermixed arrangement, have sustained communities in the Americas for thousands of years and continue to be practiced around the world. In collaboration with the Catawba Indian Nation, we assessed the yield and labor demands required when farming with Three Sisters versus monoculture arrangements. Our results illustrate how farmers could use different planting strategies depending on their priorities (e.g., maximizing yield) and available resources (e.g., conserving land, seeds, or labor). Studies like these can help inform food sovereignty programs and support cultural initiatives in Native communities. Summary Many Native American communities have historically grown maize, beans, and squash in polyculture as the Three Sisters because of the reciprocal ecological benefits the species provide each other and the surrounding environment. For instance, archaeological remains indicate that the Catawba Indian Nation had grown the Three Sisters for hundreds of years before experiencing the expansion of the colonial market economy, a smallpox epidemic, and the drastic loss of land. To support the Catawba Indian Nation's food sovereignty and traditional ecological knowledge initiatives, we assess the yield and labor demands of growing their traditional variety of maize, beans, and squash plants in the Three Sisters planting design versus in monoculture conditions. While total maize yield was equivalent in monoculture and the Three Sisters, plants grew larger, had higher survival, and produced greater yield per plant and per unit area of land in the Three Sisters. [Correction added on 21 November 2024, after first online publication: The preceding sentence has been corrected.] Squash yield was highest in monoculture. Trellising bean plants in monoculture required the most labor, and altogether, yield per hour of labor was higher in monoculture than in the Three Sisters. Ultimately, the most appropriate farming strategy for the Catawba Indian Nation to use will depend on their priorities (e.g., maximizing the production of one species versus all species). We discuss the challenges managers of small farms face when considering traditional versus modern agricultural methods and describe how a respectful partnership between the Catawba Nation and Davidson College expanded and enhanced the outcomes of this study.