It was Benjamin Franklin that said “When the well is dry, we’ll know the worth of water.” That was over 200 years ago, yet the statement holds true today.
Recent global reports on the future availability of water emphasize the fragility of this valuable resource. When it comes to commercial greenhouse production, water is critical. Its importance is not just in its use for “watering” – water is also the vehicle used to distribute nutrients and other crop management applications. Technological advancements in this area give growers an opportunity to streamline this daily function as well as take advantage of innovations that help both analyze and improve the quality of water sources.
The 2023 Commercial Greenhouse Global Market Report highlights key trends in technology such as artificial intelligence and automated irrigation systems, pH sensors and climate control software. The publication also notes the use of pH cameras and climate change tools to solve the common problems of disease prevention and pest management in the greenhouse.
Automation
Edgewood Greenhouses, located in Vernon, WI, began their automated watering program about five years ago. During the first two quarters of the year, the commercial greenhouse produces thousands of floral patio planters, hanging baskets and potted annuals for big box retailers in the Midwest.
According to owner Ken Fenske, their watering rotations are programmed from his smartphone. Timed watering segments are calculated and scheduled for different zones within each house based on that crop and that week’s sunshine/weather forecast. Sometimes old school isn’t completely abandoned, however, as he pointed to calculations written on paper attached to an old-fashioned clipboard.
Collin Benkowski, head of maintenance for the business, installed the automated watering systems customized for each greenhouse. He said individual units throughout the property were networked for ease of scheduling.
One of the programs they incorporated allows for coordinating multiple watering zones within the same house. With about 14 acres of growing space, eliminating watering by hand has saved Edgewood both staff time and the payroll that goes with it. The end result was that they were able to reduce their full-time staff by 50%.
One of the newer greenhouses on the property has several layers of floral hanging baskets with the higher tiers on an oval, mechanized track system. Unlike drip irrigation tubing, these plants are watered individually as the track slowly rotates plants to the water source. The rotation speed can be increased when the track is lowered to access product for shipping or retail stocking.
The floor of the same greenhouse incorporates an automated tube drip system, accommodating hundreds of larger geranium patio planters.
Water Quality
Automated irrigation systems are not just about improving your bottom line, however. The efficient use of this resource is also a benefit. Southwestern states in the U.S. are already imposing both residential and commercial restrictions due to the availability of water.
If trends continue, it looks like reducing water usage, recycling water runoff and storing and treating water will all be part of the growing equation in the near future. It’s not just the quantitative component that is of concern, however – what about quality?
Is your water sourced from a well or pond? Mineral issues, pathogen transmission, biofilm and pressure problems are just a few of the challenges that can accompany these water sources.
Kurt Becker, executive vice president of Dramm Corporation, spoke at the recent Commercial Growers of Wisconsin meeting. “Simple aeration systems can increase the health of your pond,” he explained. “We can also use bacterial inoculant that can help us eliminate high levels of different nutrients.”
Wells present a different set of issues. “Filtration is one of those things that I think is very underutilized in a lot of greenhouses, although if you use a well it is less of an issue,” Becker said. Filtration systems can be zoned throughout a greenhouse’s water system and issues with wells are often seen as sand and silt when the water level is drawn down.
Capacity Solutions
Becker also pointed out that tank and pump systems can be implemented when a greenhouse expands to where their well is at capacity. The example given was that of an operation with a well capable of 59 gallons per minute (gpm). The well runs at capacity for eight hours a day with peak use of 24,000 gallons per day (gpd). When the grower doubles their facility and the well is maxed out, a 50,000-gallon tank and pressurized pump integrated system is designed and installed. The tank is filled in about 16 hours and provides enough pressure to avoid drilling a second well.
A Limited Resource
A recent report by the U.S. Intelligence Council warns that “population growth, lifestyle changes, development and agricultural practices will contribute to an increasing demand for water during the next 20 years. Global water use is likely to increase by 20% to 50% above current levels by 2050. Agriculture will remain the largest overall consumer of water, but the relative increase to 2050 is likely to be smaller than other sectors.”
For those still wondering if we should be concerned about the sustainability of this important resource, Becker said it best.
“Water is an issue and it’s going to continue being and issue. Access to clean water is already an issue for many of our growers. The fact is there are more and more people every year and the same amount of water. As the world becomes smaller, clean water will become more scarce,” he stated.
Reducing usage and water runoff and storage and treatment will all be part of water technology in the near future.
by Gail March Yerke