Northwestern Washington Potato-Based Annual Cropping Systems LTARE Site

a map with the location of the mount vernon site.

Key Objective

Identify and promote management practices that enhance soil health, carbon sequestration, and the environmental and economic sustainability of agricultural systems in northwestern Washington.

Cropping System and Region

Northwestern Washington Potato-Based Annual Cropping Systems

Location

Climate and Soil Type

Annual high temperature: 59 F

Annual low temperature: 42 F

Average annual precipitation: 33 in

Primary soil type: Skagit silt loam

Established

2021

Area

16 acres with four primary treatments

Site Leaders

Gabriel LaHue - Soil Scientist, WSU

Deirdre Griffin LaHue - Soil Scientist, WSU

Chris Benedict - Weed Scientist, WSU

Collaborators

Chakradhar Mattupalli - Plant Pathologist, WSU

Louie Nottingham - Entomologist, WSU

Investigating reduced disturbance and increased organic matter additions

Treatment 1 involves high distancing and removal of crop residue, specifically in the Mount Vernon LTARE.

Treatment 1:

High disturbance and removal of crop residue in the typical crop rotation. Year 1: Potato - Fallow. Year 2: Spring Barley - Fallow. Year 3: Corn - Winter Wheat. Year 4: Winter Wheat - Fallow

  • Baling and removing residue
  • Full tillage between crops
A diagram of a treatment for weeds in a field in Mount Vernon.

Treatment 2:

High disturbance while leaving crop residue with annual cover crops in the typical crop rotation. Year 1: Potato - Cover Crop. Year 2: Spring Barley - Cover Crop. Year 3: Corn - Winter Wheat. Year 4: Winter Wheat - Cover Crop.

  • Leave crop residue after grain crops
  • Full tillage between crops
A diagram showcasing Mount Vernon's various treatment options for LTARE patients.

Treatment 3:

High disturbance while leaving crop residue with annual cover crops in the typical crop rotation. Year 1: Potato - Cover Crop. Year 2: Spring Barley - Cover Crop. Year 3: Corn - Winter Wheat. Year 4: Winter Wheat - Cover Crop.

  • Leave crop residue after grain crops
  • Both full and reduced tillage practices
  • External soil amendments incorporated
A chart with a text and a circle design at Mount Vernon.

Treatment 4:

Infrequent tillage with perennial cover crops and external soil amendments in a potato rotation. Year 1: Potato - Fallow. Year 2-4: Perennial Grass & Clover Mix

  • Perennial cover crop residue left in the field
  • Full tillage before and after potatoes
  • External soil amendment incorporated

Resources from the Mount Vernon LTARE Site