Water quality is the single most important factor in determining solubility and nutrient availability for plants. It’s especially important if you have one of the following factors:
- Well water
- Change in irrigation water source
- Multiple sources of irrigation water
- Recent flooding or droughts
The primary considerations when formulating and evaluating your plant nutrition program are:
- Nutritional content of the water
- Its effect on growing media pH
- Its content of potentially toxic components
With today’s soilless growing media, water’s alkalinity is the main area of focus. Alkalinity is a measure of how much buffering the water will provide growing media. It is similar to the amount of limestone dissolved in the water: the more lime present, the more the water will help guard against low growing media pH.
If alkalinity is too low, the growing media pH can plunge due to acidic influences like fertilizer, growing media components and plant root exudates. If this happens micronutrient toxicities can occur. Conversely, if alkalinity is too high, growing media pH can soar, leading to deficiencies in micronutrients, such as iron. In this case, you may be applying plenty of iron, but it becomes unavailable to the plant at higher growing media pH.
A thorough water analysis will measure the alkalinity of your irrigation water as well as many other elements. Having your water tested can make the difference between growing a good crop and growing a great crop!
ICL Specialty Fertilizers is dedicated to providing accurate, affordable analysis through The ICL Specialty Fertilizers Testing Lab. The Lab provides easy-to-understand reports for irrigation water that will enable you to narrow your choice of Peters® formulations based on water type.
As you can see from the map below, which is based on more than 20,000 water tests, water quality can vary greatly within one county. Accurate testing of your actual irrigation source is the only way to know exactly what your plants are getting from your water.
Water Quality Map