In its 2019-20 fiscal year, the Oregon Wine Board of Directors granted $417,000 to researchers for nine projects with the potential to advance quality grape growing and winemaking in Oregon. The update below is part of a series to let you know about the status of these projects.

Dr. Patty Skinkis is a professor and viticulture extension specialist in the Department of Horticulture at Oregon State University and member of the Oregon Wine Research Institute. She has prepared the update for the project below, which is being conducted with collaboration from Dr. Paul Schreiner, research plant physiologist, USDA-ARS.

In addition to the OWB grant, other support funds come from revenue generated from the OSU Viticulture Extension Vineyard Production course taught by Dr. Skinkis. Fruit Growers Lab, Inc. is donating nutrient analysis services.

Characterizing Willamette Valley Soil Moisture and Grapevine Response under Drying Seasonal Conditions

Project objectives:

  1. Characterize soil moisture conditions throughout the season among different soil types common to Willamette Valley wine grape production.
  2. Determine vine water status, growth, and berry development response to weather and soil moisture conditions throughout the season among different soil types.

Importance to the Oregon wine community:
Most Oregon vineyard businesses do not have budgets to support soil moisture and plant water stress monitoring and often are making best-guess estimates on when to initiate irrigation or vineyard floor management practices (e.g. tilling and mowing) that influence soil moisture. Having baseline data for the region will help Extension agents, researchers, growers, and consultants determine whether they need to be concerned about managing their soils or applying irrigation differently.

This project will provide soil moisture data over three seasons and three soil types to generate regionally-specific information about soil water content, climatic conditions, and the impacts of these factors on vine growth.

Progress so far:
The project is located in a commercial Pinot noir vineyard in Newberg, OR. Data collection was initiated in January 2020 with soil moisture sensors installed under the vine row and the middle of the alley between vine rows at a depth of 18 inches and 36 inches from the soil surface. Sensors were placed in two blocks within each of three soil types, and a weather station was installed in February 2020 to begin on-site climate monitoring. Data has been downloaded monthly, and phenology advancement and vine growth data have been collected this season, including timing of bud break, bloom, shoot growth rates, and sampling for vine nutrient analysis.

Next steps:
We will continue monitoring soil moisture and environmental data and taking measurements on vine growth and fruit development through 2022. Results of the study will be summarized and compared with other soil moisture monitoring efforts in other Willamette Valley research blocks and with the local technical group to determine how the research compares with other vineyards in the region. This work will lead to future research on the soil moisture impacts of vineyard floor practices.