Annual monoculture cropping systems in the U.S. use high inputs of fertilizers and herbicides to maximize yields, but have been shown to deplete and pollute water resources, degrade soils, increase greenhouse gas emissions, and damage natural ecosystems. Woody polyculture is a multifunctional cropping system that utilizes multiple woody and grass species grown together to produce food and forage while also providing important environmental, economic, and social benefits. As such, woody polyculture represents an understudied but potentially transformative solution needed to overcome critical challenges to the sustainability of food production. The goal of this study was to examine soil carbon sequestration in two established woody polyculture chestnut (Castanea sp.) farms in the Midwest U.S. We measured soil carbon pools (0-30 cm) in multiple fields at these two farms, and at reference annual corn-soy fields adjacent to each woody farm. Additionally, we examined the spatial patterns of ecosystem service production in multiple intercropping designs within fields at one farm.
Results/Conclusions
Preliminary results indicate that carbon content is greater in woody polyculure fields relative to reference corn-soy fields. Furthermore, we found evidence for greater soil aggregation in the woody polyculture soils, indicating this could be a likely mechanism for carbon stabilization in these woody systems. In addressing spatial patterns of soil carbon pools, we found that intercropping tended to increase soil carbon content in tree rows, demonstrating the potential for layered intercropping to increase ecosystem services production. Together, these results suggest that increased utilization of woody polyculture in the Midwest could enhance soil carbon storage.