Michael Blazier is familiar with growing trees. As an LSU AgCenter forestry researcher, he has been involved in many timber-related projects that have helped determine the most efficient methods for producing quality lumber. Now, he is working on growing switchgrass, a fast-growing native plant that shows promise as a biofuel feedstock.
“Switchgrass is native to nearly the entirety of North America. In Louisiana, it is native to the Cajun prairie ecosystem,” Blazier said.
Switchgrass can be grown on marginal lands that are not as productive for typical row crops, such as soybeans or corn. It also needs less fertilizer and is tolerant of both flooding and drought.
Blazier was taking switchgrass samples in a field near Archibald in Richland Parish with scientists from the University of Arkansas and the University of Arkansas-Monticello. The samples were to help determine switchgrass yields on various plots.
“Yields vary depending on the quality of the land it’s being grown on and the amount of inputs, such as fertilization. We’ve had yields as high as 10 dry tons per acre with only one application of fertilizer on these marginal lands that were idled for producing crops like soybeans due to their low yields,” Blazier said.
In research conducted at the LSU AgCenter Hill Farm Research Station near Homer in Claiborne Parish, Blazier has been working on growing switchgrass among pine trees. This system would give the landowner revenue from switchgrass as a biofuel and trees for lumber.
Early findings indicate that shading provided by pine trees can help establish switchgrass by preventing competition from other native species such as crabgrass. At the Archibald site, researchers are conducting a similar study using eastern cottonwood trees. A major difference is that the cottonwood trees will not be used for lumber but are being considered as a biofuel feedstock.
Hal Liechty, a forest ecologist and hydrologist at the University of Arkansas-Monticello and the University of Arkansas’s Division of Agriculture, is examining the retention of nutrients in switchgrass and cottonwood trees and comparing that to traditional row crops.
“Nutrient retention is a problem in the lower Mississippi River valley,” Liechty said. “One of the things we see with the bioenergy crops that we’re looking at, cottonwood and switchgrass is they are really good at retaining nutrients.”
Liechty is also trying to determine how much carbon is being sequestered and the potential economic benefits from carbon credits a landowner may receive by growing crops such as switchgrass and cottonwoods.
One advantage of the switchgrass system is that the carbon is stored in the soil through the roots of the switchgrass. Increasing carbon in the soil can potentially improve soil quality and crop productivity.