IN the course of co-operative investigations into problems of pasture establishment on coarse Taupo pumice, an observational minor-element trial was superimposed upon clover inoculation trials laid down by the Grasslands and Plant Disease Divisions, Department of Scientific and Industrial Research, N.Z. The soil was Kaiangaroa sandy and gravelly sand of pH 5.7 and low in available nutrients, derived from rhyolitic pumice deposited less than two thousand years ago.