358-5 Long-Term No-till, Crop Rotation, and Terrain Attribute Effects On Soil Nitrogen.



Wednesday, October 19, 2011: 9:05 AM
Henry Gonzalez Convention Center, Room 211, Concourse Level

Rachel Unger1, David Huggins2, Ian Burke2 and Dave Uberuaga2, (1)Washington State University, Pullman, WA
(2)Crop and Soil Science, Washington State University, Pullman, WA
A multi-year cropping systems study under no-tillage was initiated in 1999 on a 37 ha field of the Cook Agronomy Farm near Pullman, WA. The study objectives are to: (1) evaluate crop rotation and long-term no-tillage effects on changes in total soil nitrogen (N), (2) construct a field-scale mass-balance evaluation of N inputs, outputs, and changes in storage, and (3) relate changes in soil N to soil and terrain attributes. Crop rotations initiated in 2001 consisted of six different three year rotations of spring wheat – winter wheat – alternative crop (spring or winter plantings of barley, canola, lentil, or pea). Soil samples were initially taken at 184 geo-referenced locations in 1999 prior to establishment of no-tillage and crop rotation treatments at 30-cm depth-increments and then by soil horizon to a depth of 153 cm and analyzed for bulk density and total soil organic carbon (C) and N. Samples were collected again in 2008 at the same geo-referenced locations. In 1999, soil N ranged from 0.052 to 0.164 g N kg-1 in the top 30 cm and 0.0061 to 0.80 g N kg-1 from 30 cm to 153 cm.  We will present the 2008 data and evaluate the changes in soil N and treatment effects across the 37 ha field.
See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Site Specific Nutrient Management: I