Assessing Soil Quality in Intensive Organic Management Systems

Project Overview

Project Type: Research and Education
Funds awarded in 2003: $107,696.00
Projected End Date: 12/31/2007
Matching Non-Federal Funds: $10,772.00
Region: Western
State: Washington
Principal Investigator:
David Granatstein
WSU Tree Fruit Research and Extension Center
Craig Cogger
WSU Research and Extension Center

Annual Reports


  • Fruits: apples
  • Vegetables: beans, carrots


  • Crop Production: cover crops, municipal wastes, nutrient cycling, organic fertilizers, relay cropping
  • Education and Training: demonstration, extension, on-farm/ranch research, participatory research
  • Farm Business Management: budgets/cost and returns
  • Pest Management: flame, mulches - living, physical control
  • Soil Management: green manures, organic matter, nutrient mineralization, soil quality/health


    We evaluated the effects of cover crop, amendment, and tillage strategies on soil quality in organic vegetable and tree fruit production. In the vegetable experiment, amendment had the greatest effect across a range of soil properties. Tillage frequency affected nematode and collembola ecology. Spader tillage reduced subsurface compaction. Amendment, cover crop, and tillage all affected crop yield in at least one year. In the orchard system, wood chips led to better tree performance and fruit production than living mulch or cultivation, but not better soil quality. The economic benefit covered the cost of wood chip application. Tillage degraded soil quality.

    Project objectives:

    1. Compare the effects of selected organic row crop and orchard management systems on soil quality as measured by field and laboratory tests and field observations.

      Evaluate the NRCS Soil Conditioning Index as a tool for soil quality assessments.

      Develop underseeded cover crop guidelines for humid Northwest environments.

      Share findings with organic vegetable and fruit producers and other producers interested in sustainable practices in the Northwest.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.