Assessing Cover Crop Influence on Water Dynamics and Plant Health in Willamette Valley Hazelnut Orchards

Project Overview

Project Type: Graduate Student
Funds awarded in 2024: $29,919.00
Projected End Date: 03/31/2026
Grant Recipient: Oregon State University
Region: Western
State: Oregon
Graduate Student:
Principal Investigator:
Dr. María Zamora Re
Oregon State University
Principal Investigator:
Dr. Abigail Tomasek
Oregon State University


  • Agronomic: clovers, grass (misc. annual), grass (misc. perennial)
  • Nuts: hazelnuts


  • Crop Production: cover crops, water management, water storage
  • Education and Training: decision support system, demonstration, extension, on-farm/ranch research, participatory research, workshop
  • Soil Management: soil analysis, soil physics, soil quality/health

    Proposal abstract:

    Our project aims to assess the
    effect of cover crops on the hydrology and health of Willamette
    Valley hazelnut orchards. This research and educational
    study responds
     to preliminary
    results revealing concerns about cover crop adoption, which
    emphasized the need for detailed field-level research in regard
    to water availability.
    The main goal of this study is to
    collect and assess region and crop-specific data on orchard
    hydrology and plant-water interactions to help form informed
    decisions regarding cover crop use. More specifically, we
    want to determine how different ground cover management practices
    affect field hydrology and orchard health.
    To achieve
    this we will 1) utilize multiple
    weather stations, along
    with open-source satellite data, to obtain ET
    , 2)
    analyze the effects of cover crops on soil moisture and
    infiltration using soil moisture probes
    , 3)

    remote sensing techniques to facilitate a comprehensive
    assessment of orchard-scale plant health through NDVI,
    assess relationships between all parameters. This
    analysis will offer a nuanced understanding of how different
    cover crop management practices impact orchard health. The
    project will be conducted in collaboration with hazelnut
    producers who have already expressed interest in the research
    topic and will integrate growers' concerns with scientific
    inquiry,  to optimize agricultural productivity and
    sustainability of hazelnut orchards. The findings will be
    presented at industry meetings, field days, and a monthly coffee
    hour in addition to journal publications
    . This
    project will provide a cover crop assessment framework that can
    be used for other crops along with science-backed data to aid
    with grower decision-making

    Project objectives from proposal:


    • Objective 1 (RO1): Quantify the
      water requirements of hazelnut orchards with and without cover
      Evaluate and compare hazelnut evapotranspiration
      (ETc) estimates calculated using different methods including
      in-situ weather stations, nearby Agrimet weather stations, and
      satellite data, in order to understand the effect of cover crop
      management on water requirements of hazelnut operations in the
      Willamette Valley, OR. 
    • Objective 2 (RO2): Determine the
      effects of cover crops on soil moisture availability in
      hazelnut orchards. 
      Evaluate and compare soil moisture at two depths in hazelnut
      orchards with and without cover crops in the Willamette Valley,
    • Objective 3 (RO3): Assess crop
      health through advanced imaging technologies.

       Assess hazelnut water stress and overall health by
      comparing data such as the Normalized Difference Vegetation
      Index (NDVI) and thermal imaging data within and between
      hazelnut orchards with and without cover
    • Objective 4 (RO4): Explore the
      interconnected dynamics of environmental factors.

      Investigate how the implementation of cover crops in hazelnut
      orchards affect the relationships between
      ETc, soil moisture, and crop water


    • Objective 1 (EO1): Develop a
      centralized online resource for hazelnut orchard
      Create a website to serve as a centralized resource and
      information hub on methods for irrigation practices,
      ETc estimation, and monitoring crop water status in hazelnut
    • Objective 2 (EO2):  Address
      grower concerns through field research demonstrations and
      facilitating effective knowledge transfer.

      Investigate and disseminate research findings regarding the
      potential water and nutrient competition of cover crops in hazelnut orchards in the
      Willamette Valley. Effectively disseminate project information
      to growers and the supporting research and Extension
    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.