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 Ever-Bloom Inc. owner Ed Van Wingerden estimates that the closed-loop hydroponic system he uses has resulted in a 40 percent savings of water and fertilizer.Greenhouse growers in Carpinteria, Calif., have faced many challenges during the past decade. Growers have had to contend with new local zoning modifications that has severely restricted greenhouse expansion along with some of the state’s harshest water regulations.
In 2003, the Central Coast regional water board decided to hold Carpinteria greenhouse operations accountable to point source pollution regulations, comparable to factories and industrial sites. New regulations were implemented solely for Carpinteria greenhouses. These regulations did not apply to other greenhouse operations or to other types of farms in the Central Coast region, which were still considered as nonpoint pollution sources.
As a result of these stricter regulations, a number of Carpinteria greenhouse growers decided to install closed water recycling systems. Without the systems, they could also be subject to Waste Discharge Requirements, which entails extensive on-site monitoring and onerous reporting.
Award-winning systems
Among the first and most progressive Carpinteria greenhouse operations to implement a comprehensive water program was Ever-Bloom Inc., owned by Ed Van Wingerden. This 15-acre wholesale cut flower facility produces 275 gerbera varieties and 16 anthurium varieties. The state-of-the-art greenhouses are equipped with Q-COM computerized sensors to monitor temperature, humidity, light intensity, carbon dioxide and root zone moisture. Dual Ludvig Svensson shade/energy curtain systems provide substantial savings in energy costs.
Van Wingerden has been growing gerberas hydroponically since 1994. In 2001, the company was one of the first nurseries to install a closed-loop hydroponic watering system, which contains the excess drainage water and recirculates it. The company’s recycling system was recognized with a Green Award for environmental excellence in 2001 by the Santa Barbara County Green Awards Consortium (now known as the Green Business Program). In 2003, the Central Coast water board designated Ever-Bloom as an ideal model for other greenhouse growers to follow. The board presented the company with a Water Quality Award for its progressive irrigation recycling practices and integrated pest management program.
System specifics
Over the past 10 years, Van Wingerden has fine-tuned production in the closed-loop hydroponics system. Reverse osmosis-treated water is used because the company’s well water is high in bicarbonates. Fertilizer injection and leaching fractions using fresh RO water are computer-controlled to maintain an electrical conductivity level of 1.8 and a pH of 5.4. The leached water is primarily pumped to one of two 32,000-gallon storage tanks and recycled. Some of the water is used to irrigate the landscape outside the greenhouses or moved into a detention pond (biofilter).
Before the recycled water is re-used on greenhouse crops, it is heat-treated to 207°F to reduce pathogens. This heat treatment is a relatively inexpensive part of the process and necessary because gerberas are prone to root rot diseases caused by pathogens such as Pythium and Rhizoctonia. An energy-efficient Ecoster drain water disinfector from Van Dijk Heating with plate heat exchangers and computer-based temperature control system heats the water for pathogen control. The water is rapidly cooled for recycling.
During the summer up to 50,000 gallons of water per day is recaptured. The drain water disinfector can treat this large volume of water at a cost of less than $50 per day. Van Wingerden has investigated other pathogen control treatment systems such as ultraviolet radiation, but he continues to use the heat treatment.
After the heat-treated water cools, it is pumped to other tanks where it is blended with fresh RO water and injected with fertilizer. Fertilizer injection is computer-controlled to maintain an electrical conductivity of 1.8 and a pH of 5.4. Van Wingerden estimates his annual water and fertilizer savings at about 40 percent of his total use.
Outside the greenhouses, plants in the detention pond have been very effective in mitigating pollutants washed from the nursery during storms. The biofilter contains a mix of plants selected by Van Wingerden along with naturalized strips of vegetation.
“Water samples collected from the pond by a watchdog monitoring group were found to contain only minute amounts of nutrients,” he said. “Mowing and other maintenance of the biofilter have been minimal.”
Big on biologicals
In addition to recycling water, Ever-Bloom utilizes an IPM program that emphasizes the use of biological controls. Employees are trained to regularly scout the greenhouses for pests. They release only the required number of beneficial insects where needed. Diglyphus isaea parasitic wasps have been extremely effective for controlling leafminer. Ever-Bloom also uses Amblyseius persimilis for spider mites, A. cucumeris and A. swirskii for thrips, and A. cucumeris for broad mites and cyclamen mites. Parasitoids released for whiteflies, which are currently the major pests, are Eretmocerus (for greenhouse whitefly only) and Delphastus.
In general, Ever-Bloom uses only soft pesticides. However, some years when conditions in the surrounding hillsides are dry, thrips can be a problem. This may require the use of more traditional chemical controls that can lead to a temporary disruption in the affected areas of the entire biological control program.
Van Wingerden has found the cost for biological controls is about the same as traditional controls and offer additional benefits. The biological controls offer increased worker and environmental safety and reduce pesticide loads.
“The colors of the gerberas are more vibrant, the postharvest life is longer and the overall quality is better,” he said.
For disease pathogen control, the greenhouses start clean. Bottom and top heating and a strict sanitation program, along with the heat treatment of irrigation water before re-use, contribute to the operation’s minimal use of fungicides for disease control.
Sustainable practices
Ever-Bloom works with locally owned and operated waste hauling firms to recycle cardboard, greenwaste and scrap metal. Used rockwool is ground up and used as a soil amendment for avocado trees.
For more: Ever-Bloom, www.ever-bloom.com.
Stricter water regulations
There are nine regional water boards that administer federal and state water quality regulations in California. Currently, four regional water boards have adopted a “conditional waiver” for irrigation runoff. Conditional waiver programs require the owners of irrigated farmland to control runoff from their property.
The Central Coast Region is one of the regions with an agricultural waiver program. The Central Coast Region includes all of Santa Barbara County and extends as far north as Half Moon Bay, including 378 miles of coastline. It is one of the most productive and profitable agricultural regions in the country, reflecting a gross production value of more than $6 billion in 2008. Over 300 acres of greenhouse cut flowers worth over $100 million are produced in Santa Barbara County alone.
On Nov. 19, 2010, the Central Coast Regional Water Quality Control Board released recommendations for the region for new conditional waiver requirements which are considerably stricter than regulations currently enforced in the other three California regions. Three tier levels will apply, and those operations that are within 1,000 feet of an impaired surface water body listed for agricultural pollutants and/or use chlorpyrifos or diazinon will be designated as tier 2 or tier 3. These two tiers require onerous reporting and tier 3 requires additional individual discharge monitoring. The conditional waiver does not pertain to nursery and greenhouse operations that have point-source type discharges or to fully contained greenhouse operations that have no groundwater discharge due to impervious floors.
Flower and nursery growers representing the California Association of Nurseries and Garden Centers and the California Cut Flower Commission have voiced concerns about the new conditional waiver and hope to work with the water board to come up with some mutual resolutions. Whether or not they are successful, the greenhouse growers in Carpinteria who have implemented closed recycling systems will have a much easier time documenting compliance with the new requirements.
Although implementation of best management practices has helped Ever-Bloom comply with water quality regulations, this is not owner Ed Van Wingerden’s primary motivation. He just prefers running an eco- friendly business.
“Contrary to what people often think, environmentally sound projects are investments that often yield substantial dividends, sometimes in surprising ways,” Van Wingerden said.
For more: Central Coast Regional Water Quality Control Board, www.swrcb.ca.gov/rwqcb3.
Julie Newman is environmental horticulture farm advisor, University of California Agriculture and Natural Resources; jpnewman@ucdavis.edu.
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