Designing sustainable agroecosystems

Agricultural intensification is eroding the function and services we receive from ecosystems. Transforming corn-dominated landscapes, to include greater areas of perennial bioenergy crops – like native grasslands – may help preserve ecosystem services, while supplying renewable energy. However, gains in ecological sustainability may come at the expense of biomass production and economic viability.

grassland corn
Native and perennial grasslands can provide for ecologically sustainable bioenergy production but high-input corn is currently more profitable for farmers.

Rather than large regions dominated by a single crop type, we may be able to design more sustainable agricultural landscapes by planting different crops in specific locations that optimize crop growth, ecosystem services, and economic gain.

Ecosystem functions
Components of ecosystem multifuctionality include functions that e.g., provide pollination and pest control services, reduce pollution, maintain soil quality, and reduce greenhouse gas concentration in the atmosphere.

We are modeling a suite of biological and biogeochemical ecosystem functions (like pollination and carbon sequestration) under different bioenergy land use scenarios for Wisconsin, USA. We’re examining how functions vary individually and as a group, using an index of multifunctionality.

Ecosystem multifunctionality under different land cover/use scenarios.

We’re finding that, compared to the current land cover and use (see figure panel A), increasing bioenergy production from corn degrades ecosystem multifunctionality (B), whereas using greater areas of perennial and native grassland for bioenergy enhances multifunctionality (C). Promisingly, a “smart” design (D) that takes advantage of highly productive corn in high-fertility soils, and sustainable grasslands in low-fertility soils, while employing low-input crop management (e.g., no-till) provides the greatest benefit for the sustainability. As this work continues we will be looking more closely at trade-offs between ecological and economic sustainability and whether a trade-off is even necessary!

This work is being conducted in collaboration with Claudio Gratton at UW-Madison and Tim Meehan, who developed the land cover/use scenarios.