Trace Minerals in Food Production and Health.

S CIENTISTS face no greater problem than that of assuring that the earth's rising population be adequately clothed, housed, an'd fed. Such assurance is essential if permanent world peace is to be attained. Achievement of this objective demands effort on many fronts: improved agricultural science, chemurgy, greater utilization of photosynthetic energy, novel foods and construction materials, the harnessinig of microlife, and exploitation of marine resources. Among the possibilities is the increase of agricultural production and the nutritive value of foods by furnishing to deficient soils the minerals essential to high productivity and to the food quality upon which human health depends. In addition to the major nutrients-nitrogen, phosphorus, and potassium-plants require small amounts of "trace minermls" such as copper, zinc, iron, manganese, and molybdenum. The animal body has similar requirements, since the trace minerals, among their other vital functions, are indispensable to the enzymatic control of plant and animal physiology. Severe deficiencies of trace minerals in the soil and diet produce a wide range of striking pathological conditions in plants, livestock, and man. More dangerous are the often unrecognized subelinical deficiencies, which prevent crops from attaining full productive potentialities, subtly restrain the growth of animals, and depress the general level of human health without inducing well-defined disease. Trace-mineral deficiencies in soil, reflected in lowered essential mineral content of foods, are worldwide. Recent experience, especially in the United States, Great Britain, Australia, and New Zealand, has shown the important increases in crop production that are attainable by supplying small amounts of the trace minerals to soils that may not have been suspected of deficiency. There can be little doubt of the added benefit to human health. The growing interest in trace minerals in plant and animal nutrition is seen in the growing number of Ye!i Gladys M. Keener Executive Editor