Evaluation of Digested Manure on Potatoes and Raspberries

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2006: $19,575.00
Projected End Date: 12/31/2008
Region: Western
State: Washington
Principal Investigator:
Darryl Vander Haak
Vander Haak Dairy


  • Agronomic: potatoes
  • Fruits: berries (brambles)
  • Animal Products: dairy


  • Crop Production: nutrient cycling
  • Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research, participatory research
  • Pest Management: integrated pest management
  • Production Systems: integrated crop and livestock systems
  • Soil Management: soil analysis, composting

    Proposal summary:

    Whatcom County has a mix of dairy and horticultural farms. Both types have nutrient concerns. The dairies have excess nutrients, and the horticultural farms, mainly growing potatoes and raspberries, need nutrients. The potato and raspberry farms haven’t been inclined to use the dairy manure because of concern over pathogens in the manure, which means increasing nutrient content in critical watersheds. If the pathogen obstacle is cleared, dairy farmers could meet nutrients needs of both dairy and horticultural farms, which would reduce nutrient impacts on water quality, reduce the use of purchased chemical fertilizers and create relationships that would sustain both types of producers. The Vander Haak Dairy, the first in Washington to install an anaerobic digester, will use this grant to assess the biological and yield impacts of using digested dairy manure on seed potatoes and raspberries. It will also conduct a greenhouse study to assess common scab potential from the application of digested manure to potatoes.

    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.