If people are picky eaters, they will suffer from nutritional deficiencies due to lack of certain nutrients. Plants are the same, in addition to providing them with enough nitrogen, phosphorus, potassium three elements, but also can not lack of plants necessary for some trace elements, such as iron (Fe), copper (Cu), manganese (Mn), boron (B), zinc (Zn), molybdenum (Mo), etc., because they play an important role in many key aspects of plant life.
If these elements are missing, plants develop nutrient deficiencies, leading to stunted growth or inhibition. Experienced cultivators can often know what type of nutritional deficiency it suffers from based on external characteristics. For example, when plants lack nitrogen, the leaf surface will turn yellow; when there is a lack of iron, the new leaves appear yellowish white; when there is a lack of phosphorus, tillers and branches are reduced, the growth of young shoots and young leaves is stagnant, the stems and roots are slender, the plant is short, and the leaves appear abnormal dark green or purple red; when the plant lacks potassium, the leaves appear lack of green spots and gradually necrosis.