| Elements | Functions |
| Nitrogen (N) | It is integral part of chlorophyll. It promotes rapid growth, increase plant height and tiller number. It plays an impor tant role in synthesis of proteins, enzymes, hormones, vita mins, alkaloids, nucleic acids (DNA, RNA) etc. |
| Phosphorus (P) | It plays central role in energy transfer and protein metabo- lism. It is a constituent of sugar phosphates, nucleotides, nucleic acids, co-enzymes and phospho-lipids. |
| Potassium (K) | It helps in osmotic and ionic regulation and is required as a co-factor or activator for 40 or more enzymes. It imparts disease and drought resistance. |
| Calcium (Ca) | It is involved in cell division and plays a major role in the maintenance of membrane integrity. It is a constituent of cell wall as calcium pectate. |
| Magnesium (Mg) | It is central part of chlorophyll and it is required in several enzymes involved in phosphate transfer. It is structural com- ponent of ribosomes. |
| Sulfur (S) | Somewhat like phosphorus, it is involved in plant cell en- ergetics. It plays an important role in plant lipid synthesis and amino acids. |
| Zinc (Zn) | It is an essential component of several enzyme systems (de- hydrogenases, proteinases and peptidases including carbonic anhydrase and alcohol dehydrogenase). |
| Iron (Fe) | As a constituent of various enzymes (cytochrome, catalase, dipeptides etc.), iron plays the part of a vital catalyst in the plant. It is a key element in various redox reaction of respi- ration and photosynthesis. |
| Manganese (Mn) | It is involved in the O evolving system of photosynthesis
2 and it is a constituent of decarboxylases, kinases, oxidases etc. and hence, essential for respiration, formation of chlo- rophyll and reduction in nitrates. |
| Copper (Cu) | Acting as a component of metalloenzymes, regulating some enzymatic actions, and catalyzing oxidation reactions; Play ing a role in: i) nitrogen, protein and hormone metabolism; ii) photosynthesis and respiration. |
| Elements | Functions |
| Boron (B) | It is essential for development and growth of new cells in plant meristem. It is necessary for the germination of pol- len, formation of flowers and for the absorption of cations. |
| Molybdenum (Mo) | It’s function in rice plants is limited to the reduction of nitrate to nitrite. It is a component of nitrogenase, nitrate reductase, sulphate oxidase and xanthine hydrogenase en- zymes . |
| Chlorine (Cl) | Essential for photosynthesis and as an activator of enzymes involved in splitting of water. Associated with osmo-regula- tion of plants growing in saline soils. |
