Summary
Farming quality wine grapes in a cool climate provides different challenges to those faced by farming in a hot climate vineyard. Cool climate water needs are more about optimization of the water accumulated in the soil and surface water. SWAN Systems uses tools already in the vineyard, such as soil probes, weather stations, and remote sensing, to enhance the understanding of what’s happening in the soil and within the canopy. Using every drop of water to its full potential and managing the canopy and berry quality, SWAN Systems creates an all-encompassing forecasting tool ideal for use in cool climate growing regions.
Background
California has vast microclimates where wine grapes can thrive. The cool climate regions of California can be found in the coastal areas, parts of Northern California, and areas with elevation changes. Cooler regions in Northern California have wet winters, while coastal areas have cooler winters with less rainfall. Though both areas are within Winkler Index I and II, the rain patterns are different, and the irrigation needs will vary. Cool climate regions have their challenges, but a coordinated irrigation plan can help manage the needs of the vineyard and optimize water use. Using tools like soil probes, weather forecasts, and remote sensing allows for a complete picture of the irrigation needs throughout the year.
Challenges
Regions with longer winters, fog, and rain will have unique challenges and different timings for their vineyard practices. Irrigation planning in cool climate areas can be started by monitoring soil moisture in the soil profile early in the season. Understanding the amount of water in the vineyard’s system can help plan the needs for the rest of the year.
From winter to spring, irrigation needs are likely to be low during a wet winter. With the full soil profiles, reservoirs and waterways flowing, there is no urgency to irrigate. However, understanding what’s in the water bank will allow for educated irrigation choices when spring comes around. By looking at soil moisture readings from probes at the start of the year, insight will be gained as to what’s happening underground and provides an opportunity to set a water budget.
Spring allows for fertigation and early irrigations to occur. As canopies begin to develop, balance in vigor is needed to supply enough energy to the vine but not allow the canopy to grow too big. Canopy growth can be controlled through irrigation practices and leafing. Leafing can help keep mildew levels low in moist vineyards while allowing a suitable amount of sunlight and wind to enter the canopy. It also assists in the proper spray applications of fungicides.
During spring and summer, the focus turns to cluster maturation and Brix accumulation. Both over-irrigating and under-irrigating can be a problem in cool climates. Too much water will result in watery berries, split berries, and excessive foliage. Water-stressed vines can begin to shut down, and berries will shrivel if the permanent wilting point is reached. Further insights into summer irrigations and canopy growth can be gained through an understanding of the crop coefficient of the vines and analysis of data (e.g. NDVI) obtained from spatial imaging.
SWAN Systems
SWAN Systems is a prime instrument used by irrigators in cool climate areas due to its ability to pair with existing hardware in the vineyard. SWAN Systems can read data from most existing devices already sitting in the soil and estimate dry-down periods. These tools, paired with weather forecasting, historical data, water budgets, and spatial imaging, can give a clear view of what’s happening underground and above-ground. The SWAN dashboard allows you to view your vineyard as a whole or as individual sites. The System Suggested Irrigation (SSI) module uses the configured site data, current soil moisture and weather forecasts to provide a week’s worth of forecasted irrigation needs. This tool can be customized to allow the soil to dry while maintaining enough soil moisture for the vines to cope with any forecasted heatwaves that may be approaching. The SSI is ideal for cool climate areas due to its ability to suggest practical and substantiated irrigation plans based on growth goals and quality targets.
The ability to properly irrigate cool climate vineyards will help control vine vigor, berry health, disease, water logging, and overuse of resources and budgets. Cool climate viticulture areas can present challenges different to those experienced in warmer climates. Still, with the right tools, farmers can make the best choices allowing the cool climate viticulture characteristics of higher acidity and unique aromatics associated with these softer-bodied wines to shine in the wine.