Ten fundamentals about bioenergy: Part 6 Perennial bioenergy crop systems
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Fundamental #6: Perennial bioenergy crop systems have environmental advantages compared to annual crops.
This article will discuss the environmental advantages of perennial energy crop systems relative to annual crop systems. Second generation energy crops including switchgrass and miscanthus are warm season perennial grasses. Being perennials, they maintain a viable root system year-round and following winter dormancy they will regenerate shoot growth from the same root system that supported the plant the previous year. In the fall when the shorter days and lengthening nights signal the onset of another winter, the plant will translocate nutrients to the root system to ensure survival until the next growing season. This perennial life cycle infers distinct environmental advantages relative to annual crops:
- The continuous ground cover afforded by perennial crops reduces the potential for soil erosion.
extensive robust root system characteristic of perennial crops has the
potential to sequester more carbon than that of annual crops.
post-growing season translocation of nutrients to the root system
characteristic of perennial crops offers management options to decrease
input costs and maintain nutrients in the soil profile.
crops reduce energy inputs by not requiring annual stand establishment,
and they generally do not require herbicide inputs after stands have
studies suggest that perennial crops such as switchgrass support a more
diverse wildlife base, particularly birds, than do annual crop systems.
In earlier articles, we discussed the tremendous environmental advantages biofuels have relative to fossil fuels. Second generation bioenergy crops will further improve the already significant environmental advantage of bioenergy. The next article will discuss the importance of maintaining annual crops in our bioenergy arsenal and various management systems to improve their environmental profile.