Project Overview

• 2016 annual report

Commodities

• Fruits: grapes

Practices

• Crop Production: irrigation

• Education and Training: demonstration

The main purpose of this project is to compare basic and advanced irrigation management practices in wine grapes that will be used to help educate growers on newly available methods and practices for significantly improving water use efficiency.

Water management is a major issue in California with all growers aware of the need to adopt improved irrigation methods in the face of a diminishing water supply. Current practices continue to rely on excessive irrigation that has also been shown to lead to environmental problems through runoff and leaching of chemicals into the groundwater.

In response, the California wine industry has been at the forefront of educating growers about the economic and environmental benefits of adopting sustainable farming practices. However, existing tools for this purpose are either too generalized (ET reference tables), too expensive (soil moisture monitoring) or too labor intensive (midday or pre-dawn leaf water potential readings using a pressure chamber) to result in widespread adoption.

Costs of implementing soil moisture management technology typically cost a vineyard owner between $50 and $200 per acre per year. Despite the high costs, such monitoring systems are of limited value in precisely managing stress levels to produce higher quality grapes, forcing growers to rely on labor intensive pressure chamber readings and other vineyard tools to make accurate decisions.

More recently, irrigation management tools based on commercial crop models have been brought to the market and have been proven to be effective through extensive commercial trials in Europe and in the US. They are an appealing complement or alternative to the existing tools mentioned above for three major reasons.

First they integrate the latest findings of University based agricultural research programs about the relationship between plant physiology, prevailing climate conditions and key inputs such as water and fertilizer. This has resulted in easy-to-use Web-based tools to help growers better manage their irrigation decisions using a daily estimate of the vine water status.

Second, these models are generally offered at a much lower cost (generally between $10 and $25 per acre) offering the opportunity to drive much greater adoption of sustainable farming practices related to irrigation.

Third, because such models have been designed specifically for vineyard management, they also offer the possibility to integrate all key aspects of effective Wine grape irrigation decision making into a single platform for the first time, including visual observations of vine growth, available soil moisture data, aerial imagery and other tools already widely adopted in vineyards.

This project will utilize a vineyard crop model provided by iTK , the world’s leading commercial crop modeling company, based in France, with over 15 years of experience delivering successful crop models in Europe and the US , with over 1,000 grape growers already using their products in France.

As part of the grower outreach, a range of technology companies focused on supporting improved irrigation management in vineyards will be invited to participate in grower field days, including vendors of soil moisture, weather station and aerial imagery technology. The goal will be to demonstrate to growers a full range of options for leveraging technology solutions to meet their unique irrigation challenges.

This project will take place at Zabala Vineyards in the Salinas Valley, one of California’s major grape growing regions.

Two treatments will be compared: I) existing grower irrigation practices based on evapotranspiration measurements, and 2) advanced irrigation practices based on a more integrated approach to decision making.

Grants will be used to purchase crop modeling software, related services and a pressure chamber. Grant funds also will support personnel time to implement treatments and monitoring.

1. Contrast advanced irrigation practices and technologies in wine grapes compared to existing grower practices that are based on historic ET measurements by (a) continual tracking of actual water use and climate data, (b) weekly tracking of visual  observations of tendril condition,  leaf folding and  growth stage (c) recording all data using the Vintel software platform that incorporates weather forecasting and simulation of vine growth to provide daily estimates of leaf water potential in multiple zones of each vineyard irrigation block to support improved irrigation decision making, and (d) using a pressure chamber to calibrate and confirm the accuracy of Vintel leaf water potential values at least every two weeks.
2. Demonstrate the economic and other benefits of advanced irrigation  practices and technologies compared  to existing practices through 2 grower field days hosted in the vineyard and through presentations, videos, newsletters and trade publications
3. Develop a repeatable protocol and other guidelines for training growers on the unique requirements for irrigating wine grapes using advanced technologies and related decision support tools