Professor Kent Keller of the School of Earth and Environmental Sciences tells the story of a world ravaged by rain fall and snow melt. He said these natural environmental phenomena should leave the world without soil, and therefore without life. However, the desolate earth he describes is not the case, and a $492,000 grant from the National Science Foundation will allow Keller and his team to investigate why.

Keller and his fellow researchers, a group that includes soil scientists, microbiologists and geologists from several universities, are beginning studies of a microscopic biofilm, or slime, that exists on plant roots and acts as a catalyst for the breakdown of rocks and sand in order to access the necessary nutrients for survival.

“Soil formation, which is critical to terrestrial life, including us, is an amazing and improbable process,” Keller said. “All these nutrients should be washed away into the ocean. Our answer is that certain critical kinds of rooted plants make slimes, inside of which the reactions occur.”

Beginning next month and continuing through May, the team will plant red pine tree roots in a controlled chamber, he said. Half of the plants will receive all the nutrients they need, while the others will receive none. Their success will be measured in an attempt to understand how plants access necessary nutrients in harsh conditions.

The research suggests this micro-slime is comprised of various bacteria and other microorganisms contained in a polysaccharide gel. The bacteria are able to essentially dissolve rocks and minerals into their smaller molecular components, such as calcium, manganese and iron. The gel also serves to hydrate the plant, providing some explanation into how plants are able to survive harsh desert climates.

The biofilm serves another critical function to life on earth as well. Keller said the biofilm transforms carbon dioxide into bicarbonate, which is carried in runoff to the ocean, preventing carbon dioxide from building in the atmosphere and creating an extremely deadly greenhouse effect.

“This could contribute to understanding how carbon can be more rapidly sequestered in the terrestrial environment,” he said. “That’s more pertinent to our human timescales.”

One of Keller’s principal assistants in the project, Jim Harsh of Crop and Soil Sciences, said it appears plants are taking advantage of the process. He said the plant is more than likely feeding the bacteria and the bacteria is solubilizing nutrients in return.

“Hopefully once we understand that a little better we can translate that to how you would manage the system to take advantage of that as much as possible, or at least so you don’t mistakenly cut it off so you ruin that interrelationship,” he said.

The potential environmental implications of the research are tremendous, Keller said. He said this investigation into root structure could lead to the potential investigation of microbe root associations that could allow plants to grow in poorer soils with the use of fewer chemical fertilizers.

“Using less chemical fertilizers is generally going to be a necessary thing,” he said. “Chemical fertilizers require fossil fuel energy to transport, and we’re running out of fossil fuel energy.”

Linda Thomashow, a United States Department of Agriculture research scientist who works at WSU, serves as the microbiologist on the project.

She said when bacteria live in nature, they associate in communities. The communities found on plant roots are those that are most able to live in partnership with those plants, indicating that the bacteria have evolved to live with the plants over time.

She said an understanding of these bacteria may allow humans to grow agricultural plants even in locations where the soil should make such endeavors impossible.