On comparison of the concentration of elements between plants and humans, there are not significant differences in calcium and iron. However, the concentration of boron in plants is 140 times higher than that in humans, and that of silicon is 35 times higher. High concentrations of boron and silicon are included in agricultural products but not in fish or meat. Therefore, humans depend on vegetables and cereal crops in order to ingest silicon and boron. Since silicon and boron are useful for improving human bone density, it could be considered that the source of a healthy body rests with soil improvement agents and fertilizers used to grow agricultural products. Recently, however, the manganese, zinc and copper contents of the agricultural products in Japan are have decreased. Our research in Hyogo Prefecture has found that compost for organic cultivation alone does not supply elements due to the mechanism of microorganism, thereby reducing the concentration of manganese in plants. It is supposed that copper combines with organic matter and zinc becomes insoluble with phosphorus. Compost contains a lot of these trace elements, but they are not as available as we had expected. Efficient application methods for the trace elements including foliar and seed treatments have already been established. It is important to provide advice that these trace elements need to be applied to growing plants along with compost.