著者
村本 穣司 後藤 逸男 蜷木 翠
出版者
日本土壌肥料學會
雑誌
日本土壌肥料学雑誌 (ISSN:00290610)
巻号頁・発行日
vol.63, no.2, pp.210-215, 1992
被引用文献数
21

Rapid analysis of exchangeable cations and CEC of soils by a shaking extraction method, which can get similar values to semimicro S_<CHOLLENBERGER> method, was studied. Procedure of the method established is as follows ; Place 2.00 g of <2 mm air-dried soil in an 85 ml Nalgene centrifuge tube. Add 30 ml of 1 M ammonium acetate (pH 7), and shake for 15 min. Centrifuge the tube at 2,500 rpm for 3 min. Decant the supernatant into a 50 ml Buchner funnel fitted with filter paper, and receive the filtrate in a 100 ml volumetric flask. Repeat extraction two more times in the same manner except shaking for 30 s by hand. Add 5 ml of 20,000 ppm Sr into the flask, and make to volume with ammonium acetate. Determine Ca, Mg, K, Na and Mn by ICP-AES using calibration method. To remove free ammonium ion from the soil, add 20 ml of 80% methanol in the centrifuge tube, shake for 30 s by hand, centrifuge, and discard the supernatant through the funnel used on the extractions. Repeat this step two more times. Add 30 ml of 10% potassium chloride in the centrifuge tube, and extract absorbed ammonium ion from the soil in the same way with extracting exchangeable cations using funnel used in previous steps. Make to volume with 10% potassium chloride, dilute 5 times with water, and determine ammonium ion by an ammonia electrode method. The values obtained by this method agreed well with the values obtained by semimicro S_<CHOLLENBERGER> method on exchangeable cations and CEC of 24 soils. All extraction procedures of the method can be finished within 2 h per one sample. Repeatability of the method was about 5% for exchangeable Ca, Mg, K, and about 10% for CEC as coefficient of variance.