Available Potassium

For information about potassium in soil and its importance to plants click here.

Potassium is extracted from the soil by mixing 10 milliliters of 1 normal ammonium acetate, pH7 with a 1 gram scoop of air-dried soil and shaken for 5 minutes. The available potassium is measured by analyzing the filtered extract on an atomic absorption spectrometer set on emission mode at 776 nm. The results are reported as parts per million (ppm) of potassium (K) in the soil.