IMPLEMENT: DROUGHT RESILIENCY & IRRIGATION

Building Resiliency to Uncertain Water Availability

Reduced water availability will be one of the most significant climate change challenges faced by California vineyards. The increased variability of seasonal precipitation, lower snowpack and more frequent and intense heatwaves increase the risk for drought and may result in unreliable surface water availability. Warmer temperatures and more extreme heat days will increase water demand, which in some regions may be exacerbated by decreased winter precipitation which is necessary for soil moisture recharge. Adopting water conservation practices and creating dynamic irrigation systems can help manage for unreliable water availability.

Priority Practices Quick Links:

Reducing Water Demand

Water conservation can be achieved by reducing water demand and/or reducing water application. By increasing soil health, choosing rootstocks or scions with higher water use efficiencies, or managing grapevine canopies with water use in mind, overall water demand can be reduced. In some regions in California, winegrapes can be dry farmed, where no irrigation is used after vines are established, when specific winegrowing techniques are used.

Improve soil health to increase soil water holding capacity, through:
- Reduced tillage
- Planting cover crops and hedgerows
- Adding amendments to soil to reduce water evaporation (compost, biochar, mulch around the vines).
Avoid soil compaction with machinery which diminishes soil tilth and holding capacity resulting in excessive run off.

Water Conservation

Bonterra Fetzer Heaalsburg Photo Shoot Feb 2021-154.JPG

Impacts of Drought on Winegrapes

Drought can prevent a grower from meeting the crop’s water demands, leading to water stress on the vines.

Water stress can:

Slow plant development
Reduce nutrient uptake
Decrease crop yield
Decrease soil moisture which increases soil temperatures
In extreme cases, kill the crop

Optimizing Irrigation

Irrigation is an important tool to maintain healthy grapevines during extreme heat and drought. When irrigation water is limited or scarce, increasing your irrigation efficiency so your plants have water when you need it most will mitigate the water stress caused by climate change. Many cutting-edge and emerging technologies aim to assist growers in using a data-driven precision irrigation approach to support water conservation while maintaining grape yield and quality despite fluctuations in water availability. Growers benefit from adopting technologies that provide site-specific information on evapotranspiration the grower can adjust based on field experience. The practice of regulated deficit irrigation (RDI) can help reduce water application.

Use soil moisture probes and pressure bombs to sense soil moisture and plant stress for effective regulated deficit irrigation.
Maintain irrigation systems for optimum performance and distribution uniformity by conducting distribution uniformity tests.
Use flow meters to monitor irrigation rates and estimates of field-scale ET via surface renewal and remote sensing.
Utilize deficit irrigation strategies to balance production goals with available water resources during drought.

Irrigation Efficiency

Water Use and Greenhouse Gas Emissions

Vineyard water use can also impact GHG emissions and carbon sequestration. Wet soils harbor increased microbial activity resulting in N20 production, and wet and warm soils can increase CO2 emissions through increased microbial activity and decomposition of organic matter. Emissions can be offset by storing carbon in vine tissue, which is especially effective if the vines live for a long time. Ultimately, climate smart water management practices can conserve water and enhance winegrape quality while mitigating and adapting to the effects of climate change.

Implementation Guides:

Soil Health & Carbon Sequestration Implementation Guide: The guide includes practices and resources for improving soil health (e.g., increasing organic matter, cover crops) to increase soil water holding capacity.

Vineyard Water Use Efficiency Implementation Guide: The guide includes practices and resources for maximizing water use efficiency, regulated deficit irrigation, and optimizing irrigation systems.