For many growers, well water is a reliable source for irrigation and fertilizer application. But what if it’s affecting your crop’s potential and profits? Understanding the chemistry of your well water is important for fertilizer efficiency and maintaining soil health over time.
Reid Abbott is the field agronomy manager in the Great Plains region for AgroLiquid.
“Not everyone is aware that there’s a lot more in water than just water,” Reid said. Well water carries a variety of minerals, or cations, that accumulate as water interacts with the soil. The concentration and balance of these minerals are important, since they can impact the way you farm.
Binding, sludge, and inefficiency – oh my!
One of the first reasons to test your well water, particularly if you’re applying fertilizer through irrigation, is to prevent reactions.
“Those mineral elements can provide benefits, but they can also be antagonistic,” Reid said.
Consider:
- Nutrient binding: Certain minerals in well water can bind with the fertilizer you apply, making them inactive or less available to your crops. This means you’re investing in fertilizer that your plants can’t fully use.
- Physical blocking: In severe cases, these minerals can lead to sludge on a screen or plugged nozzles in drip irrigation systems.
- Reduced efficiency: Even without binding or clogging, an imbalanced mineral profile in well water can make your fertilizers less effective. You might be applying the correct amount of nutrients, but if the water chemistry isn’t right, your crops won’t be able to absorb them as well.
“From a fertilizer application view, it’s wise to test your water, see what’s in there, and understand how that will affect the efficiency of the products we are applying.” Reid said.
Long-term effects
After years of irrigation with well water, an accumulation of cations can affect the soil. For growers, this can have a long-term impact on soil health.
“Calcium and sodium, in particular, over time, can create a cation exchange imbalance in the soil,” Reid said. This imbalance can affect the stability of certain nutrients in the soil and the crops’ overall ability to absorb nutrients efficiently. Basically, since the soil’s natural holding capacity for nutrients is altered, nutrient absorption becomes limited making it harder for crops to get what they need.
Regional
Well water quality is more of a concern in regions like the Great Plains, where growers use aquifer-based water sources. That said, problems can also arise in surface water irrigation systems as well.
“If you have a slush and you drink it down, the less liquid you have, the more concentrated the ice gets,” he said. “It’s the same with water and minerals.”
The real-world effect can be substantial.
“If you do a soil test inside an irrigation pivot versus outside a pivot, it’s dramatically different due to cations,” Reid said. “It can be that close and that different.”
Sodium can also accumulate over time. Growers can accumulate significant amounts of salt on their land year after year.
In areas with higher rainfall, this is less of a problem, since rain will push the cations out of the root zone. This regular flushing helps prevent cation buildup. However, in drier climates where there’s less rainfall, the cations stay in the soil.
“That’s where the problems start to become even bigger, and testing the well water can help find what the soil needs,” Reid said.
Talk to the experts
Overall, testing your water source can help you be more efficient with fertilizer use, maintain soil health, and ultimately help with a better crop.
Want to talk it over? Contact the AgroLiquid crop experts.