The determination of hot‐water‐soluble boron in some acid Oregon soils using a modified azomethine‐H procedure

Abstract

Abstract A method is proposed for determination of hot‐water‐soluble boron in acid soils from western Oregon. The soil sample is boiled in 0.02 M CaCl2, filtered, and B determined using azomethine‐H. Soils extracted in this way yielded extracts with little color in them and the predicted error due to this color was 0.00–0.07 ppm B. The use of charcoal as a decolorizing agent resulted in comparatively high predicted errors. Inductively‐coupled plasma emission spectroscopic (ICP) analysis of distilled water and 0.02 M CaCl2 extracts indicated that the extractable B level was not affected by the presence of CaCl2. Azomethine‐H yielded comparable values to ICP but the curcumin method tended to give high values for hot‐water‐soluble B.