Part 1, Section 2: Soil Fertility Management
Soil Fertility Management
Potassium occurs in the soil in three forms: as exchangeable (available) potassium (K+) adsorbed onto the soil CEC; fixed by certain minerals from which it is released very slowly to available form; and in unavailable mineral forms (most of the potassium in soils). Plants take up potassium as the K+ ion.
The common source of fertilizer potassium is muriate of potash (0–0–60), which chemically is potassium chloride (KCl). Potassium chloride is highly water soluble. At excessive rates, muriate of potash can cause salt damage to plants.
Other potassium materials used in specialty fertilizers also are listed in Table 1.2-11.