Soil Community Structure, Function, and Spatial Variation in an Organic Agroecosystem

Project Overview

GW06-011
Project Type: Graduate Student
Funds awarded in 2006: $10,000.00
Projected End Date: 12/31/2008
Grant Recipient: Washington State University
Region: Western
State: Washington
Graduate Student:
Major Professor:

Annual Reports

Commodities

  • Agronomic: potatoes
  • Fruits: berries (brambles), melons
  • Vegetables: beans, beets, broccoli, cabbages, carrots, cauliflower, celery, cucurbits, eggplant, greens (leafy), onions, parsnips, peas (culinary), peppers, rutabagas, sweet corn, tomatoes, turnips, brussel sprouts
  • Additional Plants: herbs

Practices

  • Crop Production: no-till, organic fertilizers
  • Education and Training: on-farm/ranch research
  • Natural Resources/Environment: indicators
  • Soil Management: organic matter, soil analysis, soil quality/health

    Proposal abstract:

    Soil biological processes such as nitrogen mineralization, aggregate formation, and pathogen control impact farm productivity and profitability. Many high-value specialty crop growers are increasingly interested in information about the biological status of their soil but are unsure how to sample for organisms and leverage biological data for improved site-specific management. The research proposed here will address the spatial structure of soil organisms, as well as key biological processes, on an intensively farmed, organic vegetable operation. If growers better understand the spatial structure of biological communities, they can improve sampling strategies. Also, a spatially explicit sampling plan will strengthen our ability to correlate biological diversity with specific soil functions and help identify optimal management strategies. Full Circle Farm is an ideal research and outreach site; the farm’s large soil texture gradient provides a rich window for observing biological populations, and this farm is already perceived as a model by other farmers.

    Project objectives from proposal:

    1. Develop maps for soil communities (collembolans, nematodes, active bacterial, and fungal biomass) and edaphic properties (soil texture, bulk density, pH, available nitrogen, soil carbon) at Full Circle Farm and use geostatistical techniques to describe spatial structure. Develop biological indicators that correlate to important biologically mediated agronomic functions such as N-mineralization potential and aggregate stability. Recommend general biological sampling methods and interpretation guidelines based on spatial structure of communities and relation of patches to edaphic properties. Optimize farm productivity and profitability through improved management decisions. Share results with other growers and agricultural professionals via field days and farm walks, web pages, newsletters, and a presentation at WA Tilth Producers’ annual conference.
    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.