Magnesium is the central core of the chlorophyll molecule in plant tissue.

The Role of Magnesium

Magnesium is the central core of the chlorophyll molecule in plant tissue. If magnesium is deficient, the shortage of chlorophyll results in poor and stunted plant growth. Magnesium also helps to activate specific enzyme systems. Enzymes are complex substances that build, modify, or break down compounds as part of a plant’s normal metabolism.

Although magnesium is an essential element for plant growth, its use in a fertilizer program receives only minor emphasis in most areas. If magnesium is limited in the diet, animals can develop grass tetany. Therefore, some special consideration is given to the magnesium status of forage crops.

Magnesium in the Soil

Magnesium is abundant in the earth’s crust. It is found in a wide variety of minerals. Magnesium becomes available for plant use as these minerals weather or break down. For the acid soils of the east and southeastern US, the addition of dolomitic limestone in the crop rotation, is a good source of supplemental magnesium for turf and crop growth.

Magnesium is held on the surface of clay and organic matter particles. Although this exchangeable form of magnesium is available to plants, this nutrient will not readily leach from soils.