Prepare 1 M ammonium acetate (NH4OAc) solution with pH of 7.0. Fill the base of leaching tube (20 cm long and 2 cm diameter) with broth and cover it with filter paper No. 2. Weigh 10 g soil and place it in the tube and cover the soil with filter paper No. 2. Leach the soil with 100 mL of 1 M NH4OAc for 5 to 6 hours. During the leaching process do not allow the soil to dry. Wash the soil with 95% ethanol. Discard the ethanol after collection. Leach the soil with 100 mL of 0.1 M K2SO4 and collect the leachate in a 100 mL volumetric flask and make up to volume. Pipette 10 mL of the sample into distillation apparatus. Add 10 mL of 40% NaOH. Distil and collect distillate in 10 mL of 2% boric acid-indicator solution. The color changes from purple to green during distillation. Remove the 50 mL conical flask containing the distillate when twice of the original volume (20 mL) is obtained. Titrate against 0.01 M HCl or 0.01 M H2SO4 until the color changes from green to purple. This directly gives the CEC in meq/100 g of soil or cmol (+)/kg of soil. For blank, should made blank before sample. Extraction use 10 mL of 40% NaOH instead sample, after that do the same with the sample.