Farmland Studies for the Long Haul - Scientist are looking to the past to help Pacific Northwest wheat growers stay competitive in the future

Agricultural Research, Feb, 1999 by Kathryn Barry Stelljes

Experiments set up in 1931 have helped chronicle the history of farming in the Pacific Northwest.

Hot, dry, and windy. That description might not bring Oregon to mind. But some parts of the Columbia Plateau on the eastern side of Oregon's Cascade Range receive less than 10 inches of precipitation annually -- compared with 60 inches on the verdant western side of the slopes and nearly 200 inches in the coastal mountains.

The soil in this dry region of the Northeast is among the most fertile in the nation. It was left behind by glaciers, then swirled by wind and redeposited up to 150 feet thick. The plateau rings an ancient lakebed stretching from the Cascades east to Idaho, and from northeastern Oregon to Canada.

The area produces the lion's share of the nation's soft white wheat crop, worth more than $1 billion annually. Soft white wheat is preferred for Asian noodles and confections.

To help wheat growers stay competitive in the future, scientists are looking to the past.

The Columbia Plateau Conservation Research Center in Pendleton, Oregon, manages some of the longest running agricultural experiments on cultivated land in the western United States. The center is managed cooperatively by the Agricultural Research Service and Oregon State University.

Settlers first began farming here in the late 1870s. By the early 1900s, lower yields and erosion were already problems. The Pendleton experiment station was established in 1928 to provide practical solutions.

Wheat planted in October takes advantage of winter rain and snow. From April until the August harvest, the crop relies mostly on water stored in the soil. Even so, many areas are too dry to support a crop every year. To conserve water, the standard practice has been to grow wheat 1 year and leave the land unplanted, or fallow, the next.

But this causes other problems. With rain and melting snow on frozen soil -- and slopes greater than 25 percent in some areas -- the region has some of the country's worst erosion problems. And one of the most important measures of soil quality -- soil organic matter -- has declined up to 40 percent since farming started.

Taking a Long View

Experiments set up in 1931 help chronicle the history of farming in this region and now give scientists a unique resource for setting the best future course.

"These research plots give us a baseline for comparison that we could achieve in no other way," says ARS soil scientist Paul E. Rasmussen. "And studies to identify sustainable management practices and potential climate changes have created international interest in the experiments," he says. Rasmussen served as chair of the committee that oversees the experiments until 1997. He retired in early 1999 but still collaborates with the lab.

The Pendleton experiments include:

* Grass Pasture: This 150- by 360-foot plot was taken out of crop production in 1931 and represents lightly grazed grassland.

* Continuous Cereal: Three adjacent plots have been planted with cereal grains every year since 1931 as a comparison for other crop rotations. The crops grown have changed over the years and now include winter wheat, spring barley, and spring wheat. The soil is conventionally tilled with a moldboard plow.

* Residue Management: This experiment represents the typical farming techniques used in the region. In this block of plots, winter wheat has been alternated with fallow since 1931. Nine 38- by 132-foot plots receive different treatments, such as burning the wheat stubble in the fall, burning in the spring, or applying different amounts and types of nitrogen. All are conventionally tilled.

* Tillage-Fertility: Established in 1940, this experiment is also winter wheat/fallow, but it compares different types of tillage, including moldboard plow, chisel plow, and sweep tillage. Nitrogen applications also vary.

* Wheat/Pea: Since 1963, winter wheat has been alternated with a pea crop in this experiment to determine the viability and nitrogen needs of a wheat/legume rotation. These plots use four different tillage systems.

* No-Till Wheat: This experiment, set up in 1982, analyzes wheat yield and soil quality in a no-till winter wheat/fallow system. In 1997, an identical set of plots was set up so that scientists could see how the soil and crop variables change when land is Converted from conventional tillage to no-till -- also called direct seeding.

What the Research Tells Us

Data collected over 6 decades show that grain yield has nearly doubled since the 1930s, thanks to improvements in wheat varieties and soil fertility management.

The traditional farming system included fallowing every other year and tilling with a moldboard plow. But the experiments showed that the long-term environmental costs of these practices is high.

The system leaves the land vulnerable to wind and water erosion that carry away the nutrient-rich soil and require farmers to add increasing amounts of nitrogen fertilizer. In fact, the same varieties that provide higher yields need much more nitrogen. Wheat crops in the 1940s used 15 pounds of nitrogen per acre; by the 1980s, they required 80 pounds.