Kankakee Valley Post, Volume 11, Number 9, DeMotte, Jasper County, 16 January 1941 — FARM TOPICS [ARTICLE]

FARM TOPICS

DEPLETED SOILS NEED : MINERALS Plants Require Phosphorus, Potash, Nitrogen.

By DR. C. E. MILLAR

(Professor of Soils. Michigsu State College.) Man is separated from starvation only by the frail fabric of the green coloring matter in plants called ChlorophyL It is only the green plant, enefgized by light, that can combine the simple materials of nature, such as carbon dioxide of the air, water, and mineral salts from the soil into the complex substances that serve as food for man and beast. The wants of plants are comparatively few-, but it behooves man to supply them lest the plant factory fail. Natural agencies, dependent on life processes, maintain an adequate supply of carbon dioxide in the air, and as long as the life cycle persists, plants will not lack for this building material. Water, too, is supplied by a generous nature in sufficient quantities to extensive areas and by irrigation to many acres more. But how about the supply of mineral salts from the soil? That is where the pinch comes and gives man his opportunity to play the good Samaritan. Soil particles, largely rock fragments, decay slowly, setting free the mineral nutrients needed by plants. This decay process is slow, entirely too slow to meet plant requirements. Nature overcomes this obstacle by storing available nutrients in the soil through long periods of virginity during which forests or grasses occupy the land. In such a period each plant generation returns to the soil the foods it took from the soil. Man introduced a new order of events by removing from the soil the crop? grown and fattening himself and his animals on the food contained in them. Under this system, the accumulated supply of. available animal nutrients is rapidly dissipated and the crops cry out for potash, phosphoric acid, and nitrogen. Only the experienced hear these cries for they are voiced in weakened stem, distorted and discolored leaves, stunted growth, and decreased yields of food and fiber. Attention has been centered largely on the three plant nutrients—nitrogen, phosphoric acid, and potash. Virtually every soil used in farming -needs additional supplies of one or more of them. Most all fertilizers also contain appreciable quantities of calcium and sulphur and lesser amounts of several other elements which are used by plants.-