550 EXTRACTABLE POTASSIUM IN BOTANICAL MATERIALS
K
Total K, extraction by 2% acetic acid extraction. Quantitative determination by atomic emission spectrometry (AES).
Summary: This method quantitatively extracts soluble potassium (K) present in botanical materials by extraction with a solution of 2% acetic acid. Potassium is quantitatively determined in the extract using atomic emission spectrometry (AES). Concentration of potassium is used to assess plant overall nutrient status and is correlated to plant response to potassium fertilization. Generally the method has a quantitative detection limit of 0.05% (dry basis) and is generally reproducible within 8%.
Johnson, C. M. and Ulrich, A. 1959. Analytical methods for use in plant analysis. Bulletin 766. Berkeley: University of California, Agricultural Experiment Station. p. 26-78.