Long-term Residue Management Experiment: Pendleton, Oregon USA

Abstract

The Residue Management experiment is one of six long-term studies maintained by the Columbia Basin Agricultural Research Center, Oregon State University Agricultural Experiment Station. The Center is located 15 km northeast of Pendleton, Oregon at 45° 44′ north and 118° 37′ west. It lies within 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, the summers hot and dry. Precipitation occurs primarily during the winter. Annual precipitation is 420 mm, with 70% received between 1 September and 31 March. Winter precipitation falls mainly as rain, with limited duration of snow cover in most years. Average annual temperature is 10.2 °C, but ranges from -0.6 °C in January to 21.2 °C in July. Weather is measured daily 200 m from the site. Temperature and precipitation have been recorded since 1931, 10-cm soil temperature since 1962, wind speed and water evaporation since 1963, and solar radiation and humidity since 1982. Elevation is 455 m above sea level. Soils consist of loess from Pleistocene alluvial deposits overlying basalt flows of Miocene age. They are classified as coarse silty mixed mesic Typic Haploxerolls by the USDA classification system. Soils are well drained and depth to water table is greater than 50 m. Soil depth ranges from 1 to 2 m, depending upon landscape position. Soil texture is silt loam throughout the profile. The upper 30 cm of soil contains 18% clay, 70%) silt, and 12% fine sand. The area was originally a mid-grass prairie that was first cultivated in about 1885.

Oregon State University Agricultural Experiment Station Technical Paper no. 10783. Abbreviations: USDA-ARS-PWA=United States Department of Agriculture - Agricultural Rasearch Service - pacific West Area; N = Nitrogen, C = Carbon, SOM = Soil Organic matter