In virgin soil, half of a sample contains total boron 10-20 p,p.m. in dry basis and seventy-five percent of a sample contains it in available form 0.1-0.3 p.p.m. But in arable soil, sixty-three percent of a sample contains total boron 10-30 p.p.m. and available form 0.1-0.3 p.p.m. In the upper layer (0-10cm. deep) of arable soil. sixty-three percent of a sample contains available boron over 0.3 p.p.m but in the subsoil (under 10 cm. deep) eighty-three percent of a sample contains it at 0.1-0.3 p.p.m. The greatest amount of boron in available form is found in marine soil; 1.10-13.10 p.p.m. As a rule, no definite relation exists between the total and the available amounts of boron. In all samples, except marine soil, the available boron centent is less in the subsoil strata. As table 2 shows, fertilizer materials of natural origin genarally contain a high boron content. Since the boron content of various ashes is constantly high, application of these substances as potassium fertilizer will probably increase the boron content of the soil. Plants contain varying amounts of boron and the smallest amount is found in cereals. In vegetables, it is present in greater amounts in the tops than in the roots. All sea weeds except one type contain large amounts of boron, but in water weeds, the amount is very small.