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PM10, Rhizobacteria, Lind Field Day

Posted by | June 10, 2009

Promoting the Rhizosphere

A handful of soil teems with billions of organisms. And they’re all at war: Beneficial bacteria battle harmful bacteria; hungry fungi threaten to invade; nematodes devour them all.

At stake is our food supply. Plants ward off attack by pumping nutrients out through their roots, feeding beneficial bacteria and creating, in effect, an army of microscopic minions. This narrow band of soil along the roots – the thin brown line – is called the rhizosphere. It’s a place of incredible microbial activity, said David Weller, research leader with the USDA Agricultural Research Service and member of WSU’s Department of Plant Pathology.

Weller and his colleagues worldwide are creating extra firepower for embattled food crops. They gathered in May for the 8th International PGPR Workshop in Portland, Ore. PGPR stands for “plant growth-promoting rhizobacteria.” The naturally occurring bacteria are taken from the soil, then re-introduced in greater quantities so they can wage “hand-to-hand combat with pathogen organisms,” said Weller, who chaired the organizing committee for the conference. “They’re the real good guys among soil bacteria.”

PGPR also make plants more resistant to disease, fix nitrogen, produce growth-stimulating hormones and liberate soil nutrients. They can increase wheat yields up to 30 percent, Weller said, and are used on nearly every crop, from peas to pine trees to peanuts. WSU has been a world center for PGPR research for the last 30 years, he said.

“We all share the excitement and passion for using beneficial microorganisms for improving plant growth,” Weller said. “Everyone in agricultural research has a tremendous commitment to solving world hunger.”

By Richard H. Miller, Center for Distance and Professional Education

For more information on plant pathology at WSU, please visit:

participants at the PGPR Workshop

Participants at the PGPR Workshop

The mission of the Columbia Plateau PM10 project is to reduce wind erosion and particulate emissions from dryland and irrigated farms.

“Soils of the Columbia Plateau are truly unique in that they contain many small particulates that become readily suspended during wind storms when residue and soil roughness are lacking. Once airborne, these particulates can travel hundreds of miles in the air stream,” said Bill Schillinger, WSU research agronomist and the project’s principal investigator. “Our charge is to better understand the physics of small particulate emissions and find economically viable solutions for growers to control wind erosion on their farms. We have made tremendous headway on both fronts, but much remains to be done.”

The research team has extensively evaluated intensified cropping systems (e.g., less summer fallow) and alternative crops in several long-term no-till and conservation-till cropping systems studies. For irrigated growers, they documented the benefits of winter cover crops and strip-till planting.

In recent years, the team was instrumental in developing and successfully extending the undercutter method of summer fallow farming to reduce wind erosion.

“Many growers were wary of this project in the beginning, thinking our research would result in more government regulations and limit their farming options, but we soon won their trust and support,” said Schillinger. “Growers in the low-precipitation zone have commented many times that the Columbia Plateau PM10 project has done more to help them farm in an environmentally sound and profitable manner than all other previous research programs combined.”

According to Schillinger, the major remaining hurdle is to reduce dust emissions from farmland in the Horse Heaven Hills that exceede the federal air quality standard several times each year. Growers in the Horse Heaven Hills are among the most progressive soil conservationists in the state, yet face repeated drought that results in low crop yields with associated low residue production.

To learn more about the project, visit

Columbia Plateau

Columbia Plateau

Lind Field Day

Washington State University President Elson S. Floyd will be the keynote speaker at the 93rd annual Lind Dryland Research Station Field Day on Thursday, June 18. Registration for the day’s activities begins at 8:30 a.m. Tours start at 9. The lunch program will feature remarks by President Floyd, CAHNRS Dean Dan Bernardo and by Rich Koenig, chair of the WSU Department of Crop and Soil Sciences. More information about the day’s activities is by contacting Bill Schillinger at 509-235-1933,