Impacts of Shrub Willow Integration in an Agricultural Landscape on Soil Quality and Biodiversity.

Designing multifunctional landscapes for addressing multiple benefits (environmental, economic, and human health related) of agricultural systems has been highlighted as a potential avenue for increasing environmental resiliency and sustainability. Bioenergy crop integration into agricultural systems is one potential landscape design strategy to provide both cellulosic bioenergy feedstock as well as additional ecosystem services. In central Illinois, short rotation shrub willow was strategically integrated as a buffer into a corn-soybean rotation field to assess the effect of landscape position (marginal versus non-marginal land) on biomass productivity, provision of ecosystem services (soil quality) and habitat for biodiversity (microbial and macroinvertebrates). Biomass harvest after three years of growth revealed biomass production on both marginal and non-marginal land to be lower than expected (averaging 5.6 Mg ha-1 yr); with data requiring reevaluation to address two major issues including poor establishment due to environmental conditions and management impacts as well as planting anomalies resulting in lower initial planting densities. From an ecosystem service perspective, preliminary results suggest that willows may be increasing the subsurface soil organic carbon as compared to corn plots, with this trend to be monitored as the willows mature. In addition, pollinator sampling found willow introduction to have a positive effect on macroinvertebrate biodiversity which may be contributed to both crop type as well as differences in land management practices between traditional grain crop and perennial shrub willow.