Disclaimer

OSU EXTENSION LINK

If you have any comments or suggestions please contact Marcia.Sailer@oregonstate.edu
09/03/99

EXTENSION section of the
HERMISTON AGRICULTURAL RESEARCH & EXTENSION CENTER

THE LOWER UMATILLA BASIN

Grass Research

N Uptake by Legumes

HAREC Fact Sheets INDEX

Aphid Reports - Current - Archives

Aphid Map

Late Blight Report

Nematode degree day estimate Vydate Application Info

Historical Perspective
Early pioneers who traveled through the Lower Umatilla Basin (LUB) on their way to the Willamette Valley saw vast stretches of bunch grass growing on dry sandy soils. They may have felt that this area was a bit of a "sow's ear" in regard to agricultural potential and kept going west. However, after awhile some of the more astute among them came back for a second look. Perhaps they had gotten tired of trying to plow through those muddy clay soils of the "west side", or maybe they just wanted more space free from urban influences.

The Cayuse, Umatilla and Walla Walla Indian tribes had been successfully cultivating small acreages of maize and other edible seed crops along the river drainage for centuries. In the higher elevations east and south of the basin, earlier pioneers found that the increased moisture and heavier soils made them suitable for "dryland" wheat production. However, with only 9 inches of annual rainfall, and soil so sandy it could only hold about 1.2 inches of water per foot, crop production in most of the lower basin was not possible, and was useful only for limited winter grazing and hunting.

Agriculturally, however, this area had, and still has, several things going for it. At a mere 600 foot elevation, there is a 180 day growing season, plenty of sunshine, warm summer days and cool nights. In addition, those same sandy soils that limit production of "dryland" cereals, are ideal for production of high value irrigated crops like potatoes and onions.

At the turn of the century several irrigation districts began to deliver water diverted off the Umatilla River and stored in reservoirs. However, early attempts to use water to irrigate crops met with limited success because the primary method of irrigation was furrow or flood. In sandy soils, as you can imagine, furrow irrigation leaves the first part of the furrow too wet, and leaves the far end too dry. Sprinkler irrigation by wheel lines did not prove to be practical because of the large amount of labor needed to move sets every few days.

In the middle of the century two major developments turned this agricultural "sow's ear" into the silk purse it is today. The first was the evolution of center pivot irrigation. With this technology, for the first time large amounts of land could be irrigated frequently with minimal labor costs. Center pivots could also be used to "spoon feed" small amounts of nutrients to crops throughout the growing season, something essential on sandy soils with such low organic matter and clay.

The second significant advancement was the construction of large dams across the Columbia River. The McNary and John Day dams stabilized the water source, and more importantly, provided inexpensive electricity needed to lift the water up to the dry desert sands. Despite the potential drawbacks of these facilities, few can deny they have played a major role in making this area one of the most productive agricultural areas of the world. The LUB farmers achieve the highest yields of potatoes and corn in the nation.

Many other milestones have contributed to the agricultural wealth of this area, too many to mention here. But it just goes to show, that with hard work, cooperation, ingenuity, and a willingness to take a chance, it is possible to turn a sow's ear into a silk purse!

Climate
The Hermiston-Boardman area is moderately cold and humid in the winter and hot and dry in the summer with average winter lows of 35 F and summer highs of 84 F. Winds and blowing dust are common during the growing season. Annual rain fall is only about 9" per year, and crop evapotranspiration demands are high, averaging 25-30 inches of water for long season crops. Moisture-sensitive crops, such as potatoes, which require soil water levels at or above 60% of field capacity for maximum yield and quality, require irrigation almost daily in mid-season.

Soils
Fields used for the production irrigated crops in the Hermiston-Boardman area of Oregon, are generally deep, well-drained fine sandy loams of eolian origin located on terraces and terrace scarps of the Columbia River. The soils in these fields contain little organic matter (0.7-1%), are low in clay content (4-8%), have a medium to high pH (6.7-7.8 near the surface and up to 9.0 at 0.9-1.5 meters), and are inherently low in nutrients. The permeability of these soils is moderate to high with an available water holding capacity averaging about 9 to 18 cm of water per meter of soil. Though water erosion is slight, soil losses to wind erosion can be substantial. These soils have a high leaching potential for nitrates and other readily soluble materials if sufficient water is present and characterized as having a low nitrate leaching index for rain-fed, dryland farming conditions but a high index for irrigated crop production. Heavier silt loams originating in the loess and alluvium on piedmonts of the Blue Mountains are found along the Umatilla River, Buttercreek and Willow Creak river bottoms. These soils have moderately high water holding capacity but are prone to compaction and are predominately used for pasture, alfalfa, and some vegetable production.

Agricultural Practices
Without added water and fertilizers, most of the land in the Hermiston-Boardman area is suitable only for low volume grazing use due to low natural fertility and inadequate rainfall (8-12' annually). Prior to 1900, only small areas immediately adjacent to the Umatilla River were irrigated. The development of irrigation districts in the early 1900's, construc-tion of the McNary dam and locks on the Columbia, and the advent of center pivot irrigation have led to a rapid expansion of irrigated acreage. Irrigated crops such as potatoes, small grains, corn, alfalfa, and various vegetables crops are now grown on more than 200,000 irrigated acres. In recent years there has been a large increase in other high-value irrigated crops like onions, mint, grass seed, hybrid poplars, and sweet corn. Other crops such as fruit trees and grapes have seen a decrease in production.

The high water and nitrogen demands of many crops grown in the LUB, like potatoes, have been shown to contribute to the leaching of nitrates in sandy soils. Nitrogen fertilization has increased even more markedly than irrigation in the Hermiston-Boardman area over the last 40 years with nitrogen application of up to 800 lb/acre reported for potatoes! However, the LUB growers are some of the best educated in the world and readily adapt new technologies. N rates now generally match recommended rates and over 80% of the growers currently use irrigation scheduling to maximize water use efficiency and minimize leaching potentials for ag-chemicals.