Certified Crop Advisor Practice Exam

Which form of potassium is most readily available to plants?

1. Potassium sulfate

2. Solution

3. Potassium chloride

4. Potassium carbonate

The correct answer is: Solution

The most readily available form of potassium to plants is in solution. In this form, potassium ions (K+) are dissolved in water, allowing them to be easily absorbed through plant roots. The availability of potassium is greatly influenced by its solubility in water; when potassium is in a solution, it presents itself in a form that plants can quickly take up, which is crucial for their growth and metabolism. While potassium sulfate, potassium chloride, and potassium carbonate are also important sources of potassium, they must first dissolve in the soil water to release potassium ions before plants can utilize them. In comparison, the solution form is already in the most accessible state for uptake, making it the prime choice for immediate plant availability.