Wednesday, November 15, 2006

Root Length Density and Root Surface Area of Selected Pacific Northwest Crops.

Stephan Albrecht1, Clyde Douglas1, Ron Rickman1, and Don McCool2. (1) Columbia Plateau Conserv.Res.Ctr., PO Box 370, Pendleton, OR 97801-0370, United States of America, (2) USDA, Agricultural Research Service, 153 Smith Agricultural Engineering Building, Washington State University, Pullman, WA 99164

Root length density and root surface area were evaluated for soft white winter and spring wheat, spring peas and winter canola for at least two years.  Spring wheat was sampled at 3-leaf, anthesis and harvest, and spring peas at 6 to 7 node, 12 to 14 node, and harvest.  Winter wheat was sampled at 3-leaf, 6-leaf, anthesis, and harvest.  Winter canola was sampled at rosette, bolting, flowering and harvest.  Root samples were obtained from square soil cores inserted to the desired depth.  Both tube insertion and extraction was with a Giddings soil probe.  Soil was washed from roots and extraneous material (straw, chaff) was removed by hand.  Both root length density and surface area are highly influenced by environmental factors and vary greatly depending on crop season, soil depth, soil water content and soil strength.  Canola roots were affected by soil strength more than wheat or pea roots.  Greater than 95 percent of root length density in all crops evaluated was found in the smaller root diameter classes.