Horticulture

Improve Water Quality in Irrigation Reservoirs for Healthier Crops

Written by Moleaer | Apr 30, 2024 3:00:00 PM

Unpredictable weather patterns and droughts are on the rise. According to the USDA's U.S. Drought Monitor, dry conditions in the western states during the summers of 2021 and 2022 were the worst in 20 years.

The horticulture and ornamental crops industry regularly uses outdoor irrigation. Traditional sources such as municipal water and withdrawals from surface waters are often limited, and heavier restrictions are likely on the horizon. In dry times, even withdrawals from privately owned wells are often regulated.

Ornamental and horticulture growers are finding that storing water in irrigation reservoirs for an un-rainy day is becoming more of an insurance policy. Recapturing operational water and non-contaminated stormwater runoff reduces dependence on outside water sources (which may be curtailed in dry times) and saves significantly on pumping, purchasing, and treatment costs. 

Taking control of your water supply using irrigation reservoirs makes good business sense, and many ornamental crops, greenhouse, and orchard growers are doing just that.

In Chile, almond grower, Prodalmen, provides irrigation water for their 8,000-hectare crop cultivation plantation from a 6.6-million-gallon (25,000 m3) irrigation reservoir. Prominent Grevelingen, a large-scale greenhouse plants facility in the Netherlands, relies on its water storage basin for irrigation. Before implementing Moleaer’s nanobubble technology, their team relied on annual chemical dosing and the use of hydrogen peroxide on the facility equipment to eliminate pathogens and algae, but they’ve found a more sustainable solution.

Water stored in irrigation reservoirs can be a boon, especially during dry times, but it can also come with headaches. You want the water in your system to be clean and not add expense, time, or stress to your operation.

Common Challenges with Irrigation Reservoirs for Horticulture Growers

Storing water is good, but is the water high quality? A significant concern in the reuse of operational water is that it may be of poor water quality, leading to pathogen problems upon re-application. Stagnant water in an unmanaged retention reservoir can indeed be a problem. Significant levels of nitrogen and phosphorus in irrigation reservoir water can cause issues with aquatic weeds and algal growth, and suppressed DO can cause pathogen problems.

Algae

If you've seen an irrigation reservoir in the summer, it probably had algae. Warmer temperatures, abundant sunlight, and an excess of nutrients can turn a small algae problem into a large one, creating irrigation issues. Algal blooms raise turbidity, contribute to biofilm deposition in lines, clog drippers, and deplete the water’s dissolved oxygen (DO) levels when they decompose. This leads to low water quality and impacts crop cultivation.

Many horticulture growers turn to algaecides to combat these issues, attempting to clean up their water. However, dead algae can still clog filters, create problems in nozzles and drippers, and encourage anaerobic conditions. Chemical treatment is expensive and has human safety risks as well. Shocking water systems with a high dose of chlorine or peroxyacetic acid to clean the lines is laborious and dangerous for greenhouse plants, ornamental crops, and human health if not done correctly. Water quality challenges can spiral and render stored irrigation water unusable without extensive treatment and hassle.

Low Dissolved Oxygen

Warm water already carries less oxygen–lower DO levels–than colder water. Add in issues with algae growth, and those numbers can plummet. Irrigation with low DO water isn't as effective for crop cultivation and contributes to low oxygen levels in the root zone.

Low oxygen availability in the substrate affects plant root growth and respiration. For horticulture and ornamental crops, the result is smaller plants that are slower to fill containers and take longer for a crop cycle. Plants need access to oxygen in the root zone for optimum root respiration. Without it, plant growth is affected, and anaerobic conditions conducive to pathogens like Pythium and Phytophthora are created.

Pathogens

Prevention is more desirable and cheaper than correction. Keeping pathogen levels low is the goal. Many ornamental crops producers are forced into high chemical usage to stay ahead of the issue. Waterborne pathogen problems can start in irrigation reservoirs, spread throughout the system, and be difficult to control. Extensive levels of biological contaminants reduce the effectiveness of chemical and UV treatments, requiring higher doses at increased cost.

Nanobubbles Improve Irrigation Reservoirs Water Quality

Nanobubble treatment of irrigation reservoirs helps improve water quality to provide a quick ROI for horticulture growers. Moleaer's nanobubble technology provides a chemical-free and sustainable solution that treats common irrigation reservoir problems with added benefits seen at the crop level. Benefits in crop cultivation include:

  • Higher quality crop yields and greenhouse plants
  • Healthier, more robust root systems
  • Greenhouse plants and ornamental crops that better withstand environmental and other stressors

Increase your irrigation reservoir DO levels

Raising dissolved oxygen with aeration is a chemical-free way to control algae found in irrigation reservoirs, but typical aerators are inefficient. Conventional bubbles rise to the surface and burst, limiting their time in contact with the water and, thus, their effectiveness.

Nanobubble technology, on the other hand, has an oxygen transfer efficiency of over 85 percent per foot of water as confirmed by third-party testing.

Nanobubble benefits are seen beyond the irrigation system and have been shown to prevent and reduce pathogens like Pythium and Phytophthora by as much as 90%.

Clean up lines and drippers

By increasing the DO concentrations, nanobubbles increase the oxidation-reduction potential (ORP) of the irrigation water which promotes the growth and proliferation of beneficial aerobic microbes. This leads to the reduction of dissolved contaminants and inhibition of algae growth, lending to less clogging of dripper tubes, irrigation lines and equipment.

Nanobubbles reduce biofilm by scouring the inside of drip lines and other exposed surfaces in the irrigation system piping and fittings.  

Easy integration and lower costs  with Moleaer’s nanobubble technology

Nanobubble treatment can be used with existing chemistry and systems like UV treatment that are already installed. Prominent Grevelingen no longer needs to dose their irrigation reservoir with hydrogen peroxide after installing Moleaer’s nanobubble system. They've saved money on operational and maintenance costs, including reducing the frequency of changing biofilters and using 50% less hydrogen peroxide for cleaning. Less expense and fewer problems mean less stress for you.

Check out our case studies to see how other greenhouse plants growers like you use nanobubble technology to solve water quality problems and increase yields with a chemical-free, scalable solution.