Effects of Subsurface Micro-irrigation on Water Use Efficiency and Grapevine Growth

View the project final report

Commodities

• Fruits: grapes

Practices

• Crop Production: drought tolerance, greenhouses, irrigation, water management
• Education and Training: demonstration, display, extension, mentoring, networking, on-farm/ranch research, participatory research, workshop
• Production Systems: agroecosystems

Grape-based agriculture in the Western SARE region has been a major industry historically with rapid expansion occurring in recent decades in the Pacific Northwest. However, water for crop irrigation now faces potential limits owing to multiple competing demands from the public and from unstable climatic patterns. Development of more highly efficient irrigation methods are necessary for producers to meet this resource use challenge. Working in close collaboration with vineyard owners and managers in southcentral Washington, our research group introduced a novel subsurface micro-irrigation strategy named Direct Root-Zone irrigation (DRZ), which uses hard tubes to deliver the water directly from surface drip lines into the lower root zone of grapevines with flexible choices of irrigation rate and water delivery depth. We conducted both field and greenhouse research to clarify the advantages of DRZ on crop water use efficiency and grapevine performance, and transmitted our research findings to growers through collaboration, on-farm demonstration, popular press releases, podcasts and presentations. DRZ may provide a convenient water management strategy in orchards under seasonal drought, and offers the potential to minimize water use and improve water use efficiency without reducing grape quality. Moreover, deeper subsurface delivery depth does not affect grape yield and quality, but may encourage deep rooting to enhance drought tolerance in grapevine under water deficit. Growers have showed their interests in applying this novel irrigation strategy in their commercial orchards. In addition, a couple of plant nurseries, suppliers of irrigation equipment and scientists have expressed their willingness to collaborate with us for current and future related research projects.

Overall goal: Achieve comprehensive understanding of subsurface micro-irrigation impacts on grapevine growth and wine quality by determining minimal amounts of water required to achieve acceptable fruit quality. Growers will be directly engaged with this project through planned program activities to translate research-based findings to provide efficient and sustainable irrigation methods for vineyard managers to utilize during periods of limited water availability.

Objective 1: Evaluate efficiency of our subsurface micro-irrigation strategy on water conservation

• Sub-objective 1: Calculate water saved without diminishing fruit quality

• Sub-objective 2: Compare differences in water use efficiency between subsurface micro-irrigation and surface drip irrigation

• Sub-objective 3: Determine combinations of water delivery amount and irrigation depth yielding highest water use efficiency
  

Objective 2: Measure the impact of our new subsurface micro-irrigation strategy on grapevine growth and fruit quality

• Sub-objective 1: Assess role of subsurface micro-irrigation strategy in partitioning carbohydrates within the grapevine

• Sub-objective 2: Quantify subsurface micro-irrigation effects on root distribution and abscisic acid (ABA) exudation

• Sub-objective 3: Analyze vital nutrient content in grapes
  

Objective 3: Educate vineyard producers and engage community members on irrigation water conservation and wine grape quality improvement

• Sub-objective 1: Conduct extension workshops or field days to educate producers about improving wine grape quality by using less irrigation water
• Sub-objective 2: Develop educational materials for vineyard managers and growers to conserve irrigation water and improve water use efficiency