Evaluation of the Effects of Vineyard Floor Management Practices on Soil Microbiology

Project Overview

Project Type: Research and Education
Funds awarded in 2002: $27,496.00
Projected End Date: 12/31/2005
Matching Non-Federal Funds: $21,225.00
Region: Western
State: California
Principal Investigator:
Richard Smith
University of California Cooperative Extension

Annual Reports


  • Fruits: grapes


  • Crop Production: conservation tillage
  • Education and Training: demonstration, extension
  • Farm Business Management: budgets/cost and returns
  • Pest Management: chemical control, physical control, precision herbicide use, weed ecology
  • Production Systems: agroecosystems
  • Soil Management: green manures, soil analysis


    A long-term comparison of various vineyard floor management practices (weed control and cover crops) indicates that weed control treatments had no impact on soil microbial biomass, but had a significant interactive effect with the rye cover crop on mycorrhizal colonization of grapevine roots, presumably due to differential effects on the composition of weed species that also host mycorrhizal fungi. Cover crops increased soil microbial biomass in the row middles, and there is some evidence that they may increase microbial biomass in adjacent vine rows. Cover crops increased soil organic matter and reduced levels of soil nitrate and phosphorus, which can help reduce losses of these nutrients in runoff.

    Project objectives:

    1. To examine the changes that occur over multiple years in microbial biomass, abundance and diversity of soil mycorrhizae, and associated nutrient availability in a long-term evaluation of alternative vineyard floor management strategies in comparison with the standard practices utilized on the Central Coast of California.

    2. To extend the information developed by this project through University of California Cooperative Extension viticulture program for the Central Coast and through outreach efforts of the Central Coast Vineyard Team. Outreach efforts are to include field days, seminars, and articles in newsletter articles and industry trade journals.

    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.