What Causes Water Quality Problems in Irrigation?

Problems with water quality in horticulture is an ongoing battle that has escalated over the last decade. The threat of pathogens and algae in irrigation water is something that all farmers have to contend with on a daily basis. And, as with any battle - there are some winners and some losers. Let’s shed some light on the basics of cause and effect to make this ongoing dilemma simpler to solve. Let's look at what contributes to the water quality of commercial irrigation.

How Do Droughts Affect Irrigation Water Quality?

At any particular time, some part of the US, and the planet for that matter is experiencing a major drought. And in states like California that provide fruit and vegetables for our entire country, a significant drought like the one during 2012 to 2016 can be devastating to both growers and consumers.

Although the 2012-2016 drought in California has officially ended, other parts of the western US are still experiencing extremely dry conditions. Take a look at this continuously updated US Drought Map issued by the United States Drought Monitor.

During droughts, local water-management authorities are forced to regulate and restrict irrigation supply and agriculture runoff. So, unless modern farmers use technology to their advantage, water restrictions resulting from drought conditions can push them out of business.

Droughts create a water scarcity, which drives up the price for both the farmer and consumer. If farmers choose to cut costs in their water treatment systems, crop vitality, and quality decline and consumer health concerns arise.

2. Add The Key Facts of Urbanization

More people are moving to big cities like NYC or New Jersey where fresh produce is hard to find in the winter months. Or Las Vegas where water is scare year round. As urbanization increases, the problem of having enough fresh fruits and vegetables for the millions of city dwellers is becoming more evident.

Not everyone lives in California’s Central Valley where fresh fruits and vegetables are readily available year-round. For consumers in large cities or on the East Coast, the delivery of their “fresh" vegetables” may have taken several days or weeks which drastically shortens shelf life.

Consumers are becoming more concerned about the safety of the fruits and vegetables they’re purchasing.

Here’s what the USDA has to say in their article: Foodborne Pathogens Associated with Fresh Fruits and Vegetables.

“The U.S. Public Health Service has identified a number of microorganisms associated with foodborne illness that are notable either because of the severity or because of the prevalence of the illness they cause. Foodborne microbial pathogens associated with the consumption of fresh fruits and vegetables include"

Brought to you by USDA's Economic Research Service

Cyclospora cayetanensis
Escherichia coli
hepatitis A virus
Listeria monocytogenes
Norovirus
Salmonella
Shigella

This article tells us that no matter our growing method, open air, greenhouse, hydroponics, vertical farming, or alternative we have a responsibility to ensure the fruits and vegetables we grow are safe.

Increased Demand for Organic Produce

Consumers want what consumers want. And for over 30 years it’s been organic. Here’s a quote from the article “Organic Market Overview”:

“Fresh fruits and vegetables have been the top-selling category of organically grown food since the organic food industry started retailing products over 3 decades ago, and they are still outselling other food categories, according to the Nutrition Business Journal. Produce accounted for 43 percent of U.S. organic food sales in 2012.”

Goals & Priorities of Effective Water Treatment

The goal of modern farmers isn’t to sterilize their water. They understand that many microorganisms are beneficial to both humans and plant growth. The real goal is to reduce the risk of pathogens. At Voeks, Inc. we work to do this within the budget of the grower.

We look at the grower’s location, current irrigation system, sources and quality of water and go from there.

As with any project, it’s good to start out with a list. Here is a water quality checklist from UMass Amherst - the Center for Agriculture, Food and the Environment. See what points you already have in and what you need help with.

CHECKLIST WATER QUALITY FOR CROP PRODUCTION
Have water tested at a laboratory that is equipped to test water for irrigation purposes. Irrigation water tests should always include pH and alkalinity.
Reclaimed water, runoff water, or recycled water may require reconditioning before use for irrigation since disease organisms, soluble salts and traces of organic chemicals may be present.
Water quality should be tested to ensure it is acceptable for plant growth and to minimize the risk of discharging pollutants to surface or groundwater.
Use filtration to remove suspended solids from water to prevent clogging of piping, valves, nozzles, and emitters in an irrigation system. Suspended solids include sand, soil, leaves, organic matter, algae, and weeds. Water pH may need to be adjusted before being used for mixing some pesticides, floral preservatives, and growth regulators.
Reference: UMass Extention 2018 Water Quality for Crop Production