Irrigation water quality matters

Free essential minerals or hidden threats?

Plants are made up to 95% from water. At first glance, pure irrigation water may contain impurities or contaminants that could place plant health in danger.

Irrigation water quality could be evaluated by its physical, chemical and biological characteristics. Physical parameters such as temperature, turbidity, and salinity (EC) are essential in assessing water quality. In fact, the higher the EC, the less water is available to plants. A global meta-analysis of 1151 comparisons from 120 peer-reviewed publications reported up to 17.3% decline in crop yield when high salinity content water was used for irrigation.

Depending on the source, irrigation water may contain impurities, such as heavy metals, pesticide residues, and high mineral, salt or sodium content. Bacteria, viruses, and other microorganisms in irrigation water can pose health risks to crops and humans if not properly managed.

Inappropriate pH can affect nutrient availability, while excessive nutrients or contaminants can harm crops and the environment. Plants could rapidly uptake certain minerals from the hydroponic solution, while other minerals supplied with irrigation water could accumulate in the solution to toxic levels. High levels of salts and sodium could reduce plant water uptake while highly acidic or alkaline pH could affect nutrient availability.

Different crops have varying levels of tolerance to poor water quality. Some crops can withstand higher salinity or alkalinity levels than others. Regular monitoring and testing of irrigation water quality are essential to identify problems early and make necessary adjustments to ensure crop health and productivity.

Fortunately, several effective water treatment technologies are available to mitigate the effects of poor water quality. Such techniques include filtration, chemical additives, or desalination, depending on the specific issues.