What is a common source of potassium in fertilizers?

Potash is recognized as a common source of potassium in fertilizers because it specifically refers to potassium-rich salts, which are essential for plant growth. Potassium is a key nutrient that supports various plant processes, including water regulation, enzyme activation, and photosynthesis. Potash typically comes from naturally occurring mineral deposits or evaporated seawater, making it a widely utilized and effective source in agricultural practices to enhance soil fertility and crop yields.

Other sources mentioned, while significant in their own right, do not primarily provide potassium. Superphosphate is mainly a source of phosphorus; urea delivers nitrogen; and calcium nitrate provides both calcium and nitrogen but lacks potassium. Thus, potash stands out distinctly as the primary potassium source, aligning with common agricultural practices.