Thus, if Mg 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. Micronutrient Requirements of Crops Crops require 16 essential elements to grow properly. Ail the remaining nutrients used by plants come from soil in the form of inorganic salts.
Legumes are an exception because they can also fix nitrogen from the air.
Micronutrients in crop production Micronutrients are essential plant nutrients that are required by plants in very small amounts. The very small quantities required do not mean that they are less important in plant nutrition. Micronutrients are as essential to plant growth as nitrogen and potassium which are required in very large quantities. This practice is called nitrogen chemigation but is more commonly referred to as fertigation. This practice has been widely used by irrigating farmers for several years.