MACRO NUTRIENTS: 1, 2, 3 - Carbon, Hydrogen and Oxygen: These three elements are referred to as frame work elements. These elements constitute the major part of dry weight of the plant Carbon 45%, Oxygen 43%, and Hydrogen 6%. These elements are not mineral in origin. They enter into composition of all organic compounds of the plants. They are taken up by plants in the form of 〖CO〗_2 and water. Carbon is absorbed in the form of 〖CO〗_2 from air. It is essential for the synthesis of carbohydrates and fats which build the cell wall, protoplasm etc. Hydrogen & Oxygen are present in water which is absorbed by the plant from the soil. Water is indispensable for various vital activities in the plants.
4. Nitrogen: 1.5% Source: soil and atmosphere bacteria and blue green algae and utilize atmospheric N_2. Obtained as: Nitrates, Nitrites and Ammonium salts.Functions: Nitrogen is a component of proteins (essential for protein synthesis), amino acids, nucleic acids, chlorophyll, cytochrome enzymes (photosynthesis and respiration), alkaloids, plant harmones, and vitamins.Deficiency symptoms: Deficiency of Nitrogen leads to: 1 Chlorosis 2 Depreciation of Anthocyanin pigment. 3 Flowering is delayed. 4 Fruits underdeveloped.
5. Phosphorus: 0.2% Source: Soil in the form of H_2 〖po〗_4^- and H〖po〗_4^(2-) Component: It is a component of nucleic acids, nucleoproteins, phospholipids, ATP, NADP. Highest amount is present in meristematic parts, maturing seeds and fruits. Functions: Synthesis of nucleoproteins and important in processes like photosynthesis and respiration. Deficiency symptoms:Deficiency of Phosphorus leads to: 1 Stunted growth. 2 Dead necrotic spots on leaves. 3 Depreciation of anthocyanin pigment 4 Flowering is delayed.

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