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

View the project report

Commodities

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

Practices

• 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

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) use remote sensing techniques to facilitate a comprehensive assessment of orchard-scale plant health through NDVI, 4) 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. 

Research Objectives: 

• Objective 1 (RO1): Quantify the water requirements of hazelnut orchards with and without cover crops. 
  • 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,
    OR. 

• 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 crops.  

• 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 stress. 

Educational Objectives: 

• Objective 1 (EO1): Develop a
  centralized online resource for hazelnut orchard
  management.
  • 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 orchards. 

• 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 community.