Leopold Center for Sustainable Agriculture

Videos describe research on biochar in ecosystems

Back to Leopold Letter Winter 2012

By MELISSA LAMBERTON, Leopold Center graduate research assistant

As optimism grows about the benefits of applying biochar to farmland, researchers have turned their attention to a neglected topic: how biochar affects natural ecosystems.

Biochar, a carbon-rich material similar to charcoal, is created as a byproduct of burning feedstock at high temperatures in a low-oxygen environment, a process to make biofuel called pyrolysis. When applied to crop fields, biochar has many of the same benefits for soil health as fertilizer, and also sequesters carbon underground for decades or centuries.

The principal investigators of a Leopold Center project, Stan Harpole and Lori Biederman, ISU Ecology, Evolution and Organismal Biology, analyzed recent research on biochar and found that as much as 50 percent of what is applied can move from crop fields into nearby prairies, forests and waterways.

“There’s been a lot of attention on biochar as this new miracle product that can solve multiple problems in terms of energy and environment,” Harpole said. “But there isn’t really much information about its effect on things other than crops.”

To fill that knowledge gap, the researchers established 30 replicated plots in the Loess Hills treated with additions of biochar and manure, and planted a diverse mixture of tallgrass prairie species. The experiment is featured in a new On the Ground video, “Biochar and Prairie Biodiversity,” on the Leopold Center website.

Preliminary results suggest that biochar has a positive effect on plant and soil biodiversity. That could be good news for farmers, who wouldn’t have to worry about biochar blowing off their fields into nearby natural areas. It also might give ecologists a useful tool for restoring prairies.

However, Biederman noted that while plants thrived with biochar additions, mycorrhizae, important soil fungi that have symbiotic relationships with plant roots, diminished. “The jury is still out,” she said. The researchers will continue collecting field data for at least one more year.

Uncertainty also surrounds the effects of biochar on aquatic systems. In a basic laboratory test, Harpole discovered that biochar dissolved into water killed algae. He is now working to design a more realistic experiment that mimics how biochar moves through soil into waterways.

“The experiment is so new that it’s too soon to tell what will happen,” Harpole said. “Biochar has so many different ways that it can work in the environment that you’re never sure which is going to be the important one.”

A second video, “Biochar and Organic Tomatoes,” describes a related project at TableTop Farm where ISU Environmental Sciences and Agronomy student Erich Sneller is applying biochar to Sun Gold cherry tomatoes. The experiment compares plants growing with and without biochar, either inoculated with mycorrhizae or sterilized.  

Sneller envisions that farmers could supply future biofuel plants with feedstock, such as corn stover, and receive biochar in return, creating a cycle that would continually improve soil health.

“It’s good for the soil and good for your wallet,” Sneller said. “We’re hoping we’ll see some positive effects with soil fertility and increased plant growth.”

The research is funded by the Leopold Center’s Ecology Initiative and conducted with assistance from the ISU Western Research and Demonstration Farm and TableTop Farm.

Back to Leopold Letter Winter 2012