Comparatively large errors can be introduced during pretreatment steps. A close examination of the Berger‐Truog hot water extraction method (1) revealed that errors were introduced not only during the boiling but also during the filtering. Extraction methods to determine what is called “plant available boron” are poorly understood chemically, and have not been thoroughly examined. Poor standardization of the pretreatment methods leads to inaccurate and unreproducible data. In the case of the hot water extraction procedure, according to Berger and Truog (1), the most critical steps are the filtering step and the boiling. Five minutes boiling time is not enough to achieve equilibrium. Boric acid added to a soil sample could usually not be reextracted. The recovery was sometimes less than 79%.