Raspberry Producers Reduce Water Use on the Central Coast
The IssueThe Central Coast supplies the nation’s grocery stores with a diversity of fruits and vegetables during much of the year. Because few guidelines are available, it is difficult for growers to accurately schedule irrigations to avoid over irrigating. Over-irrigation can cause nitrate contamination of groundwater. Many wells in the region have nitrate levels above the EPA safe drinking water standard. Over-irrigation leads to an increase in runoff, sometimes contaminated with agricultural chemicals and silt, which can harm sensitive eco systems in rivers, creeks and the ocean. Pumping too much groundwater for irrigation also draws seawater into the aquifers, leading to higher water prices to pay for developing alternative water supplies.
What Has ANR Done?Working with the nation's largest berry producer, University of California Cooperative Extension advisors were able to conduct nine on-farm irrigation trials with different water application rates. Using a combination of weather and soil moisture monitoring techniques, raspberry growers were able to reduce water use by as much as 50 percent without losing berry yield. This method of irrigating allows growers to adjust their watering schedule to match changes in weather conditions, and results in improved fruit quality.
Major raspberry producer has significantly lowered water-use and improved qualityGrowers had been using three or four acre-feet of water per season in raspberries, but the research determined that water application could be as low as 18 acre-inches and still optimize yield. The reduced usage of water translates to less leaching of nitrate away from the plant roots and less drainage water making its way into local waterways that lead to the ocean.
Through consultations and group trainings conducted by UCCE and industry representatives, this weather-based method of scheduling irrigations has been implemented company-wide. Without sacrificing yield, growers have been able to improve fruit quality while using less water.
Supporting Unit:Monterey County
Michael Cahn, Irrigation and Water Resources Advisor, UC Cooperative Extension, Monterey County, 1432 Abbott St., Salinas CA 93901,(831)759-7377
Mark Bolda, Strawberry and Caneberry advisor, UC Cooperative Extension, Santa Cruz County, 1432 Freedom Blvd.,Watsonville CA 95076,(831) 763-8025