Abstract:
Annual ryegrass is grown for seed on Dayton, Bashaw, and similar poorly drained soils in western Oregon. Dayton, called “white soil” by growers, is found on broad, flat areas of the southern Willamette Valley floor. Bashaw,
a black, sticky clay sometimes called “gumbo soil” by growers, is formed on the low-lying and gently concave areas associated with narrow stream valleys and at the edges of some hill slopes. These soils are not well suited to
perennial grass production because of poor drainage, which causes water to stand on the soil surface. Recommendations in this guide assume production in these settings and apply to commonly grown varieties of annual ryegrass.
