Climate and Soils
The Pendleton Agricultural Research Center was established in 1929 as a branch station of Oregon State University. The center is located 9 miles northeast of Pendleton, in the northeastern corner of Oregon. It is presently known as the Columbia Basin Agricultural Research Center, and is administered by the OSU Agric. Expt. Stn. The Columbia Plateau Conservation Research Center, administered by USDA-ARS, is immediately adjacent. Research facilities are shared jointly by the staff of both agencies.
The research center is located in the Columbia Plateau physiographic province between the Cascade and Rocky mountains. The climate is semi-arid, but partially influenced by maritime winds from the Pacific ocean. Winters are cool and wet, and summers are hot and dry. Precipitation occurs primarily in the winter, in direct contrast to climatic patterns in the midwestern and eastern U.S. Nearly 70% of the total precipitation falls between September 1 and April 1. The area is characterized by gently to strongly sloping landscapes developed in loess overlying basalt. Loess deposits are relatively young, and range in depth from 0.1 to >5 m. Slopes range from 0 to 50%, with the majority in the 7-25% range. Soils are well drained except those close to drainageways. Virgin vegetation was a shrub-grassland or sagebrush-grassland steppe, with Idaho fescue (Festuca idahoensis) and Sandberg bluegrass (Agropyron spicatum) as the dominant species. Drier landscapes had lesser amounts of sagebrush (Artemesia tridentata) and wetter areas low-growing shrubs (Symphiocarpos albus). Downy brome (Bromus tectorum L.) was an early invader after land was broken for cultivation.
The research center is located on a gently sloping landscape, with slopes ranging from 0 to 5%. Average temperature is 50F, but ranges from 31 in January to 70 in July. Annual precipitation averages 16.5 inches. Winter precipitation falls mainly as rain with limited duration of snow cover in most years. The elevation is 1495 feet above sea level. Soils are coarse silty mixed mesic Typic Haploxerolls(Walla Walla silt loam). The upper 12 inches of soil has a CEC of 18 cmol kg-1, a bulk density of 1.2- 1.3 , and a pH ranging from 5.3 to 7.0 depending on past treatment. The top 12 inches of soil contains about 18% clay and 70% silt. The area was first broken for cultivation in the mid 1880s, and was farmed for about 50 years when the station was established. All wheat grown in these experiments is soft white wheat unless otherwise noted.
The Sherman Branch Experiment Station was established in 1909 by the Oregon Legislature. The station is located near Moro in the center of Sherman County in northeastern Oregon. The station is presently known as the Columbia Basin Agricultural Research Center, and is administered by the OSU Agric. Experiment Station.
The station contains 234 acres, 200 of which are tillable. This area has rolling fields with slopes from 3% to 30%. Soil is classified as Walla Walla silt loam (Typic Haploxerolls). This site was selected for the experiment' station because it was representative of much of the area in the wheat belt of the Columbia Basin of Oregon. The experimental farm has the typical slopes of the area. The elevation at the office is 1,835 feet. The climate is semiarid, but partially influenced by maritime winds from the Pacific ocean. Approximately 70% of precipitation occurs in the coldest months, from November through March. Annual precipitation averages 11.4 inches. Average temperature is 44F but ranges from 32F in January to 70F in July.