Deficiencies of essential elements disrupt plant growth and development

Obtaining some of the essential elements is not a problem for plants. For example, carbon dioxide is always present in the air, and water is usually abundant enough to support at least minimal growth. As a result, deficiencies of carbon, hydrogen, and oxygen rarely occur in plants. Plants also require large amounts of nitrogen, phosphorus, and potassium; low levels of these elements in soils almost always limit plant growth, and, as a result, these are the elements most likely to be deficient in soil. Thus, plant growth and development largely depend on a plant's ability to absorb these minerals. Overcoming deficiencies of these elements in crop fields and gardens often requires adding large amounts of fertilizer.

Deficiencies of micronutrients are corrected more easily. For example, molybdenum-deficient soil can be replenished by annually adding less than 4 grams (less than the weight of a nickel) of molybdenum to a hectare of land, and deficiencies of zinc and iron have been corrected by driving zinc-coated (galvanized) tacks or nails into the trunks of trees. Examples of deficiency symptoms of essential elements are found in table 7.1 and shown in figure 7.30.

FIGURE 7.30

Nutrient deficiencies produce distinctive symptoms. (a) Potassium deficiency causes leaves to curl at their edges. (b) Iron deficiency causes chlorotic leaves (veins remain green). A deficiency of manganese produces similar symptoms.

FIGURE 7.30

Nutrient deficiencies produce distinctive symptoms. (a) Potassium deficiency causes leaves to curl at their edges. (b) Iron deficiency causes chlorotic leaves (veins remain green). A deficiency of manganese produces similar symptoms.

The Essential Chart Iridology
(a)
Mineral Deficient Leaves Tree
(b)

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