Concentrations of more than 50 soil elements can now be determined by atomicabsorption photometry, X-rayfluorescence spectrometry, inductively coupledplasma mass spectrometry, and other techniques (Yamasaki1996, Takeda et al.2004). Concentrations of the major soil elements, Si, Al, Fe, Ca, Mg, Na, K, Mn, Ti,and P, are frequently measured. Other major elements, O, H, C, N, S, F, and Cl, existin …