# Soil erosion and lateral carbon fluxes from corn stover-derived biofuel

## TL;DR

Removing corn stover for biofuel can increase soil erosion and carbon loss, which should be considered in biofuel supply chain design.

## Contribution

The study quantifies the impact of corn stover removal on soil erosion and lateral carbon fluxes in the U.S. Midwest.

## Key findings

- Corn stover removal can increase soil erosion beyond acceptable thresholds in some cropping systems.
- Eroded soil organic carbon from stover removal is comparable to other life cycle impacts of biofuel production.
- The impact varies with removal intensity, conservation practices, and crop rotation.

## Abstract

Crop residues hold promise to alleviate food vs. fuel competition and contribute to biofuel production. However, the impacts of lateral sediment and carbon fluxes caused by residue removal are not fully understood. Here we employ agroecosystem modeling to conservatively estimate lateral sediment and carbon fluxes resulting from partial corn stover removal in the U.S. Midwest. Results show substantial increases in soil erosion resulting from corn stover removal. For example, the area of continuous corn and corn soybean cropping systems exceeding soil erosion tolerance threshold could increase from 1.1 to 13.3% because of 66% corn stover removal. Depending on removal intensity, conservation, and crop rotation, the stover removal-induced increases in eroded soil organic carbon is equivalent to 3.9–12.5 gCO2e MJ−1, which is comparable to other components of the life cycle impacts of corn stover-derived biofuel. Our findings highlight the need to consider the soil erosion and lateral carbon fluxes impacts of corn stover removal in designing supply chains for cellulosic biofuel production.