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ARS Home » Pacific West Area » Pendleton, Oregon » Columbia Plateau Conservation Research Center » Research » Publications at this Location » Publication #95613
Title: THIRTY-YEAR RAINFALL TRENDS, IMPLICATIONS FOR CROP YEILD IN THE COLUMBIA PLATEAU

Author
item Rasmussen, Paul
item PAYNE, WILLIAM - OREGON STATE UNIVERSITY
item Goller, Roger

Submitted to: Wheat Life
Publication Type: Trade Journal
Publication Acceptance Date: 8/1/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Rainfall distribution has a substantial effect on crop yield in dryland regions of the Pacific Northwest. There has been a distinct trend at eight rainfall-reporting sites in Oregon, Washington, and Idaho towards less over winter (1 Sept.-31 March) precipitation, and more growing- season (1 April-30 June) rainfall. Crop yield in long-term experiments at Pendleton, Oregon over the past 30 years is highly correlated with changing trends, with annually cropped cereals and spring crops such as wheat and peas especially favored by increasing growing-season rainfall. The risk of low crop yield under annual cropping is higher than that for a winter wheat/summer fallow rotation, but the 2-yr-production level is much more favorable. Annual cropping promotes soil organic matter retention and reduces soil erosion, leading to more favorable sustainability of agriculture.

Technical Abstract: Rainfall distribution has a substantial effect on cereal yield in dryland regions of the Pacific Northwest. There has been a distinct trend at eight rainfall-reporting sites in Oregon, Washington, and Idaho towards decreasing over winter (1 Sept. - 31 March) precipitation, and increasing growing-season (1 April - 30 June) rainfall. Crop yield in long-term experiments at Pendleton, Oregon over the past 30 years is highly correlated with changing precipitation trends, with annually cropped cereals and spring crops especially favored higher growing season rainfall. The range in wheat yield under annual cropping is higher than that for a winter wheat/summer fallow rotation, but the 2-yr-production level is much more favorable. Annual cropping promotes soil organic matter retention and reduces soil erosion rates, leading to better sustainability of agriculture.