360 EXCHANGEABLE POTASSIUM, CALCIUM, MAGNESIUM, AND SODIUM
Fertility: X-K, X-Ca, X-Mg, X-Na,
Equilibrium extraction of soil for plant available exchangeable potassium, sodium, calcium and magnesium using 1 Normal ammonium acetate (pH 7.0) and subsequent determination by atomic absorption/emission spectrometry.
Summary: This method is semi-quantitative and determines the amount of soil exchangeable K, Ca, Mg, and Na residing on the soil colloid exchange sites by displacement with ammonium acetate solution buffered to pH 7.0. Generally, these cations are associated with the exchange capacity of the soil. The method does not correct for calcium and magnesium extracted as free carbonates or gypsum. The method has a detection limit approximately of 1 ppm or 0.01 meq/100g.
Sample amount requested: 10 g (for one or up to all four elements)
Questions concerning limited sample size can be answered by the DANR Analytical Laboratory.