By Rachael Cavanaugh
Talking about ways to conserve water isn’t just for hippies and eco-activists anymore.
The water crisis in California continues to mount, and states all across the Western U.S. are bracing themselves for the effects of critically low snowpack in the mountains. The drought has slowly forced cannabis growers to consider how the escalating shortages could impact their crops and take a deeper look at water-saving techniques and technologies.
“I think that the awareness is just now hitting everybody,” said Jeff Stockdale, chief operating officer for Ambient Water Corp. “There are a lot of people looking for solutions and just now starting to budget for the potential impact of our changing water situation.”
Based out of Spokane, Washington, Ambient Water creates systems that produce clean water by taking moisture from the air and turning it into potable water. The firm has been marketing this technology, which it calls “atmospheric water generation,” to commercial and residential markets for years. However, it is currently developing a new product with specific applications for cannabis growers.
The new system, scheduled to be on the market by mid-summer, will apply the same technology used in the residential units to create a closed-loop environment for greenhouses.
The system will harvest the internal humidity of the greenhouses and convert that moisture into water to be used to irrigate the plants.
“By harvesting humidity that the plants are naturally creating through their transpiration process and reusing that water for irrigation, we’re dramatically reducing the amount of outside water that is required in that operation,” Stockdale said.
Ambient Water is just one of many companies developing and marketing water-saving innovations to the cannabis industry.
Another technology on the rise is wireless gardening systems. These systems go a step beyond basic timed irrigation methods, allowing growers to micro-control how and when they water their plants, monitoring the irrigation from their phones or other wireless devices. The vigilance comes from moisture sensors that growers install around the plants to measure water content.
SmartBee Controllers offers a system that uses a web-based app to monitor and manage water content.
Jason Hadley, a spokesman for the firm, says the technology was designed “by growers, for growers.” In addition to irrigation, it monitors factors like lighting, humidity, CO2 functionality and temperature.
Growers can set up programmed actions to account for varying grow room conditions for maximum control.
A feature SmartBee calls its “water content sensor module” uses probes around the plants to measure the average water content of the grow area, as well its root zone temperature.
Users can determine high and low points for optimal water levels and then use a slider on the app to adjust them.
“If your water content falls below into the danger zone you can set it up to automatically initiate a watering,” Hadley said. “On the other side, if your water content is too high and you’re approaching a timed watering, it will cut off that watering.”
The company also offers a handheld meter that growers can use to spot check areas that don’t have probes.
“You’re able to gauge exactly what your plants need so you don’t under or over water,” Hadley said.
All of this contributes to preventing water waste and maximizing water efficiency.
Another water-saving irrigation method on the rise in the use of capillary mats. These are essentially bottom-feeding irrigation systems that sit underneath the plants and provide water from the ground up.
“You water the mat and the mat waters the plants,” said Ryan Croy, a sales representative for Grower Mats, which is a branch of parent company WaterPulse.
Croy said the water-saving benefits of the grow mats are significant.
“By doing this you use a tremendous amount less water,” he said.
Croy said the mats are especially popular with cannabis growers because they also reduce standing water, minimizing root rot and other problems associated with excess water.
Beyond emerging technologies like grow mats, wireless irrigation and humidity harvesting, there are also basic gardening techniques that can help growers reduce their water footprint.
One step when working outdoors is to plant directly into the ground rather than into containers, said Chris Bayley, owner of the consulting company Hortistructure. The method mitigates water wasted through evaporation.
“The evaporation rate just out of the container with the sun beating down on it is just tremendous,” he said. “The plants just use so much more water.”
Bayley also pointed to soil management as an excellent technique for reducing overall water usage. Planting mixes are quite effective at controlling the rate at which water seeps into the ground, and adding water polymers helps the soil release the water more slowly. Biochar, a carbon-rich type of charcoal, is particularly effective, he says.
Jennifer Martin, an independent cultivation consultant with MarijuanaPropagation.com, said water consumption can be reduced by growing indoors whenever possible. Although the plants are in containers, they tend to be smaller and in controlled container sizes, she said.
“The water stays in those containers for some period of days,” Martin said. “Whereas outdoors you’ve got much larger plants that are exposed to hotter temperatures and the hot sun on them so they use a lot more water per plant. The water doesn’t stay contained because the plants aren’t in pots.”
Drip irrigation is another easy way to conserve water, she says. Instead of flooding a plant and having “a bunch of extra water that completely drenches it,” Martin said to add water only as needed.
“It takes somebody trying to be conscious about water before they are using considerably less,” she said. “But it definitely can be done.”
Whatever the strategy, the consensus among industry experts is that a thorough, well-planned irrigation strategy is necessary for a successful grow operation — not to mention for the public water supply at large.
Stockdale pointed to the mass quantity of news stories right now that are associated with the current water shortage.
“It’s a list that’s longer than your arm of all of the problems that are now being perceived,” he said.
“If we lose a significant portion of the agriculture that comes out of California, what’s the impact on the rest of the world, let alone the United States? We think in Washington State we’re okay. We’ve got mountains, we’ve got snow. … Well guess what? It’s not self-contained. We’re all affected by this and we’ve all got to pitch in and figure out how to solve some really hard problems.”
Croy agreed, noting that a unique challenge to the water scarcity issue is that there aren’t any alternative methods to obtain the resource.
“Desalination is expensive and not very practical,” he said. “You can’t ship water to somebody. And the ground source water that people are drilling to get for wells is depleting at a very rapid rate. In addition to that, the demand is growing. So we have a decreased supply of water with an increased demand. … It’s just a perfect storm.”
He added that for cannabis production especially, it is the only necessary component that can’t be made artificially.
“It’s the only element of growing that they can’t just create, that’s not artificial,” he said. “They can make the light. They can make the soils. They can make everything else. … The water is the only source that is not replaceable.”