Abstract:
In the late 1980s, the U.S. Pacific Northwest potato industry faced a crisis. Potato tuber quality was inadequate to meet the needs of potato processing companies due to a condition called “sugar ends” or “dark ends” in fried tuber
slices. This defect was common in tubers grown on stressed Russet Burbank plants, but the stresses aggravating the condition were poorly defined. Growers lost contracted acres. In 1989, northern Malheur County was declared a groundwater management area due to groundwater nitrate contamination. The
groundwater contamination was linked, at least in part, to furrow irrigation of potato. All irrigation systems in arid regions require some leaching
fraction to avoid salt accumulation. However, with the high nitrogen fertilizer rates used through the 1980s, and heavy water applications on
furrow-irrigated potato, nitrogen and other mobile nutrients were readily lost to deep percolation and in runoff.
