Which fertilizer is commonly used for potassium application in crop production?

Potassium chloride (KCl) is commonly used for potassium application in crop production because it provides a readily available source of potassium, an essential nutrient for plants. Potassium plays a vital role in various physiological processes in plants, including water regulation, enzyme activation, and photosynthesis. It helps improve crop quality and resistance to disease and environmental stress.

KCl is favored in agricultural practices due to its high potassium content and the fact that it is relatively inexpensive and widely available. Its use helps ensure that crops receive the necessary potassium to maximize growth and yield.

Other options like urea and mono-ammonium phosphate primarily provide nitrogen and phosphorus, respectively. While calcium nitrate supplies both calcium and nitrogen, none of these options deliver potassium efficiently, making potassium chloride the most suitable choice for potassium supplementation in crop production.