Growers Respond to Water Challenges with Efficiency Improvements

Dr Loren Oki, left, rates plants in UC Davis field trials, part of the Climate Ready Landscape Plants research project to find varieties that perform well with little water. Picture: Dr. Loren Ok

Everyone knows that water is a precious resource. With the ongoing drought in the West and Southeast, farmers are learning how to cut back on their water use. Federal, state, and local regulations govern how water is treated, reused, and released, and the cost of water continues to rise.

Growers face this problem head-on with a diverse array of options available. The key is to use less water and reuse as much as possible. Growers, researchers, advocates, and other industry professionals are coming together to reduce their water use.

Clean Water R3 Educates Growers

Clean WateR3 is a federally funded Specialty Crops Research Initiative grant focused on outreach to help growers reduce, remediate, and recycle irrigation water. Dr. Sarah White of Clemson University is in charge of the grant team and Dr. Paul Fisher of the University of Florida continues to educate growers. The grant was completed in 2019 but continued by Dr. Fisher’s website, CleanWater3.org, is up-to-date on helpful information for growers.

“Our next phase of this project is to look at water treatment technologies that we can add to help growers treat the water that circulates inside their greenhouses, or if they need to pour the water into the environment, there are technologies such as constructed wetlands and bioreactors that can capture nitrogen, phosphorous, and pesticides,” said Fisher.

In late 2022, Fisher taught an online course on water quality and treatment to 95 growers in the class.

There are a couple of key differences between indoor and outdoor production when it comes to water, Fisher said. Outdoors, rainfall is usually the largest component of irrigation. Outdoor growers focus on avoiding excess water, managing water in retention ponds for reuse, and stopping storm water from entering the soil.

Indoor growers focus on recirculating nutrient solutions. To avoid dumping a nutrient solution down the drain, growers sanitize, balance nutrients, and reuse water. Fisher said that he is currently working on projects with two water treatments, cold plasma and ozone, to clean the recurring nutrient solution.

“The advantage is that they both break down in oxygen and water, so there are no harmful chemicals,” Fisher said.

Although water is scarcer and more expensive in the West, Fisher says all growers see the cost of water and fertilizer, which has greatly increased costs. Indoor growers and hydroponic growers don’t want to waste nutrients in their water.

“For many farmers today, access to water resources is limited. Growers really understand the value of capture and reuse,” said Fisher. “Not just California, everywhere in the US”

Fisher said growers are willing to invest in water purification and recirculation systems, but sometimes the capital investment is high. In this case, growers can do a cost-benefit analysis for infrastructure to capture rain from the roof of a greenhouse or create a retention pond.

“A combination of water and fertilizer costs, access to water resources, and increasing regulations regarding water quality and the amount that can run off your property, are all key drivers. for this investment,” Fisher said.

Dr. Tom Fernandez of Michigan State University is currently leading an effort to apply for a grant to further research water conservation and water treatment. Researchers are looking for letters of support from industry stakeholders to submit their grant application. Those interested can contact Fisher for more information at [email protected]

Climate Ready Landscape Plants

To reduce water use, a group of university professors researched drought-tolerant plant species. Lorence Oki, Cooperative Extension Specialist at the University of California, Davis, leads the Climate Ready Landscape Plants research project. Six western universities are working with USDA grant funding to research which varieties do best with less water in a two-year trial. Oki said universities have tested about 250 varieties so far.

Some of the results of the field trials were surprising, Oki said. For example, consumers tend to think of roses as plants that need a lot of water. But some cultivars need less water.

“Most of the information available on plant water use is anecdotal and not based on research,” says Oki. “With our field research, we can get a real science behind it.”

Although the tests did not include only new varieties, the universities asked plant distributors to submit new plants for testing. Ball Ornamentals, Star Roses and Plants, among others have become strong advocates, Oki said.

Oki says the biggest impact is the end consumer. The university’s test gardens host three open house days throughout the year and invite horticulture professionals to rate the plants. Landscape designers and architects appreciate seeing how plants behave after some time in the ground instead of seeing them in a container in a nursery. Water agencies also use field test results to improve water conservation in the landscape. Breeders also add this information to their marketing materials.

“Plant developers are starting to use our information in their marketing materials,” Oki said. “Kurapia, a low-water used groundcover, says ‘UC tested.'”

Green Acres Nursery and Supply, a regional retail nursery with locations in California and Texas, receives requests from landscape designers for plants they see in trials at UC Davis.

“That’s part of the strategy – to invite professionals to the scene,” he said. “They can request these plants to be planted and sold to consumers. Ultimately, the goal is to have landscapes that use less water.”

Advocate for Change

Chris Udall, Executive Director of the Agribusiness and Water Council of Arizona, says a 23-year drought affecting the Colorado River is causing the squeeze. Despite some bright spots, Arizona, along with other basin states, is in a crunch for water and hydropower availability. Farmers and ranchers want to continue operating, he said, but they need some payment to make a profit.

“We’re not looking for a handout,” Udall said of the need for long-term, low-interest loans. “We want the opportunity to bring our infrastructure into the 21st century and make our facilities more drought-resistant.”

For example, pumping water leads to higher energy costs for both outdoor and indoor growers. Greenhouse growers are looking for new, innovative solutions to produce more crops with less water, such as switching to drip and pressurized irrigation systems.

The Colorado River was budgeted to have 16.5 million acre-feet of water, but currently has 12 million acre-feet of water flowing, according to Dr. Jeff Silvertooth, Professor of Soil, Water, and Environmental Science at the University of Arizona. Udall says the basin states have not been able to reach an agreement on how much water each state will use, but they are continuing the dialogue.

“Many think the federal government could step in and ask for mandatory cuts. What that will look like is anyone’s guess. Some say it will be a combination of voluntary and mandatory cuts,” Udall said. . “It’s hard when you’re used to a lot of acre feet coming into the system and we’re nowhere near that right now. It’s definitely going to be painful for everyone.”

Udall recommends that growers continue to innovate in their water use practices. By trying new things, they may find irrigation systems that save water or find better ways to treat and reuse their water. Growers are also welcome to join the Agribusiness and Water Council of Arizona, along with universities, water and electric districts, and consultants, to work together and promote the best interests of all.