Basic Nutrients for Plant Growth

Like all other organisms, plants require various nutrients for their growth. Among the various nutrients, they get most of them from organic or inorganic fertilizers and all minerals, and the rest from the atmosphere and water. If the amount of these essential nutrients is less, the deficiency syndrome can be observed in the plant and if the amount is too much, the toxicity also causes problems in the growth of the plant.

Macronutrients: Nitrogen (N), Phosphorus (P), Potassium (K).
Micronutrients: Boron(B), Chlorine(Cl), Manganese(Mn), Iron(Fe), Nickel(Ni), Copper(Cu), Zinc(Zn), Molybdenum(Mo).
Secondary nutrients: Magnesium(Mg), Sulphur(S), Calcium(Ca).
Non-mineral nutrients: Hydrogen(H), Carbon(C), Oxygen(O).

Plant nutrients supplied from soil minerals, organic or inorganic fertilizers:

Nitrogen:

Functions:

• N combines with H, C, S, and O to form amino acids, which are recognized as the building blocks of proteins. Amino acids play a special role in forming protoplasm as well as cell division and thus providing functions for plant growth and development.

• It is considered a special part of the chlorophyll molecule and plays a special role in photosynthesis.

• It is also considered an essential component of some vitamins.

• It helps in maintaining the quantity and quality of dry matter in leafy vegetables. It also maintains the protein content of grains.

Deficiency:

• Stagnant growth is likely due to decreased cell division.

• Pale green to light yellow (chlorosis) usually appears on older leaves from the tip first. The transfer of N from older to younger tissues may cause death and/or shedding of older leaves depending on the severity of the deficiency.

• Reduced N results in reduced protein content of seeds and plant parts. In some cases, flowering is greatly reduced.

• N deficiency results in the early ripening of some crops, resulting in significantly lower yield and quality.

Phosphorus:
Functions:

• In respiration and photosynthesis, the contribution of P to energy transfer and storage as ADP and ATP and DPN and TPN is undeniable.

• P is known to be part of RNA and DNA structures, which are recognized as the main components of genetic information.

• The highest concentrations of P are observed in seeds in a mature plant and P is required in young cells such as shoot and root tips, where high metabolism and rapid cell division are observed.

• P plays a special role in the root, seed, and fruit development as well as flower initiation.

• P helps to reduce disease incidence in some plants as well as improves the quality of some crops.

Deficiency:

• Since the requirement for large amounts of P is observed in the early stages of cell division, slow, stunted and weak growth is the primary overall symptom.

• P is relatively mobile in plants as well as can be translocated to new growth sites, causing dark to blue-green coloration to be observed in the older leaves of some plants. Severe deficiency results in purple discoloration of leaves and stems.

• Maturity is delayed and poor seed and fruit development are observed in P deficiency.

Potassium:
Functions:

• K plays no role in the formation of important organic compounds in plants. However, K makes an essential contribution to plant growth because K can promote metabolism as an enzyme activator.

• K plays a special role in controlling plant water use by the opening and closing of leaf stomata, where water is released for cooling plants.

• In the photosynthesis process, the contribution of K to maintaining the electrical charge balance at the ATP production site is undeniable.

• K helps promote the transport of photosynthesis (sugars) for the growth of plants or storage in roots or fruits.

• In addition to aiding in ATP production, K is involved in protein synthesis.

• K contributes particularly to improving plant resistance to disease, improving grain and seed size, and improving the quality of vegetables as well as fruits.

Deficiency:

• Chlorosis along the edges of the leaves i.e. scorching of the leaf margins is considered to be the primary symptom that occurs first on older leaves.

• K is required for photosynthesis as well as protein synthesis, lack of which slows and stunts plant growth.

• K deficiency causes weak stems in some crops.

• The size of fruits and seeds is reduced as well as their yield.

Calcium:
Functions:

• The contribution of Ca is immense in the formation of a cell wall membrane and its plasticity which plays a role in influencing normal cell division while maintaining membrane permeability and cell integrity.

• Ca plays a major role as an activator of various enzyme systems in carbohydrate metabolism as well as protein synthesis.

• Ca combines with anions including sulfates, phosphates, and organic acids to provide functionality as a detoxifying agent through the neutralization of organic acids in plants.

• Ca provides functionality for seed production in groundnut.

• Ca indirectly reduces soil acidity when soil is calcareous, which improves crop yield.

Deficiency:

• Ca is not translocated into the plant causing symptoms to appear first in young leaves as well as leaf tips. Roots and growing tips of leaves turn brown and eventually die.

• Lack of sufficient Ca causes newly emerging leaves to stick together at the edges, causing the leaves to tear as they expand. As a result, the structure of the stem is also likely to be weakened.

• In some crops, young leaves shrivel and terminal buds die.

• Some crops drop buds and flowers prematurely.

Magnesium:
Functions:

• Mg is considered a major component of chlorophyll molecules which is actively involved in photosynthesis.

• Mg activates phosphorylation processes as a co-factor in several enzymatic reactions.

• The role of Mg is immense in stabilizing ribosome particles and in stabilizing the structure of nucleic acids.

• Mg facilitates the movement of sugars within a plant.

Deficiency:

• Symptoms of its deficiency as interveinal chlorosis first appear on older leaves. Leaf tissue between veins may turn bronze or reddish, yellow, while the leaf veins are green. Maize leaves show yellow stripes with green veins, while crops like potato, tomato, soybean, and cabbage show orange-yellow color with green veins.

• In some cases, symptoms may appear on young leaves and premature leaf drop.

• Symptoms are also manifested in acid soils as well as soils that are receiving high amounts of Ca or K fertilizers.

Sulfur:
Functions:

• S plays an immense role in the formation of proteins derived from a component of certain amino acids.

• It actively participates in the metabolism of coenzyme A and B vitamins biotin and thiamine.

• S contributes significantly to chlorophyll formation, seed production, stabilization of protein structure, and nodule formation in legumes.

Deficiency:

• Thin, woody, and stiff plant stems are observed.

• There are similarities between S and N deficiency symptoms which mostly occur in Sandy soils because these kinds of soils are not rich enough in organic matter as well as moderate to heavy rainfall is received by them.

• Delay in maturity is observed as well a retarding growth rate is noticed.

Boron:
Functions:

• B plays an immense role in RNA formation as well as in the synthesis of a base in cellular functions.

• B helps promote root growth.

• B contributes significantly to pollen germination as well as pollen tube growth.

• B plays an important role in specific enzyme activity, seed and cell wall formation, sugar transport, and lignin synthesis.

Deficiency:

• Generally, B deficiency causes stunted growth, with symptoms first appearing in growing points as well as young leaves. The leaves may thicken to curl and lastly become brittle.

• In many crops, symptoms are well expressed such as:

  • Peanuts: hollow hearts

  • Beets: black heart

  • Celery: Crooked and cracked stems

  • Carnation: division of calyx

  • Papaya: Deformed and lumpy fruit

  • Cabbage, cauliflower, and broccoli: in pith hollow stem

  • Chinese cabbage: Midrib cracks, and turns brown.

Iron:
Functions:

• Fe is part of the protein ferredoxin and is essential in sulfate and nitrate reduction.

• The role of Fe in the synthesis, as well as the maintenance of chlorophyll in plants, is immense.

• Fe participates in protein metabolism.

• Fe is important in the heme enzyme system of plant metabolism.

Deficiency:

• Interveinal chlorosis is observed in young leaves. Fe is involved in the production of chlorophyll so the youngest leaves can be white.

• Commonly seen in alkaline or excessively calcareous soils.

Copper:
Functions:

• Cu is required by almost all plants because of its enzyme activity.

• In plants, Cu is the part of protein plastocyanin, which is needed to build electron chains.

• Cu may have a role in photosynthesis or plant stability by producing enzymes.

Deficiency:

• Lack of Cu reduces the growth of the plant, and the shape and color of the young leaves of the plant may change. There may also be necrosis of the apical meristem.

• In larger trees, the growing parts of the tree have many branches, resulting in a bushy appearance. New leaves also turn yellow.

• In young grass, the tips and growing parts of the grass are affected first, resulting in stunted growth.

Manganese:
Functions:

• Mn mainly functions as part of the plant enzyme system. It also participates in many metabolic functions. It acts as a constituent of pyruvate carboxylase.

• Also, Mn helps during oxidation removal in the photosynthesis process.

• Mn is also involved in photosystem II, and it is also involved in photolysis.

• Mn helps to activate indole acetic acid.

Deficiency:

• Mn deficiency causes chlorosis disease, which results in small yellow spots in plants.

• In monocots, greenish-gray spots appear on the base of the plant's leaves. These spots may eventually turn orange in color.

• In legumes, marsh spotting occurs due to Mn deficiency, which results in the development of necrotic areas in the cotyledon regions.

Chlorine:
Functions:

• Cl is an essential part of the photosynthesis process, it is used in the evolution of oxygen.

• Cl increases the water-holding capacity of leaf tissues and regulates tissue osmotic pressure.

• Many bacteria and fungi contain Cl.

• Cl protects plants from fungal attacks.

Deficiency:

• A deficiency of Cl causes the disease of plants called chlorosis and the plants begin to wither.

• Since Cl is found in the atmosphere and rainwater, its deficiency is rarely noticed.

Zinc:
Functions:

• Zn is an essential element in tryptophan synthesis as it enables plants to form indole acetic acid.

• Zn acts as an essential component of some metalloenzymes in many cases. So a variety of plants is essential. It is required in metabolism.

• Zn is also involved in protein synthesis and is also essential for RNA synthesis.

Deficiency:

• Zn deficiency causes interveinal chlorosis in young leaves, similar to Fe deficiency. However, Zn deficiency is more severe, with chlorosis occurring along the entire length of the leaves.

• In vegetables, Zn deficiency changes the color of the young leaves and the newly grown leaves are pale and deformed.

• In citrus, leaves with small holes appear, and the structure of the fruit is distorted, called interveinal chlorosis.

Molybdenum:
Functions:

• Mo is an essential element in plants that is essential for two enzymes, nitrogenase, and nitrate reductase.

• There are some microorganisms in the soil, which fix nitrogen, in which case Mo is essential.

Deficiency:

• Whatever deficiency is observed in plants due to lack of N, the same is true for lack of Mo, as these two elements act almost identically, such as curling of leaves along the margins, and yellowing of older leaves.

• Necrotic spots are observed along the leaf margins of the plant.

• Plant growth is stunted and flowering stops.

Nickel:
Functions:

• It is an essential micronutrient for plants. Ni increases the water-holding capacity of plant roots.

• Ni is an active component of the plant enzyme urease, which helps to hydrolyze urea in active plant tissues.

• It is an important part of the process of photosynthesis and transpiration.

Deficiency:

• Leaves begin to fall on the top of the canopy of the tree.

• Also, the growth of the plant is disturbed or the plant grows abnormally.

Plant nutrients derived from the atmosphere and soil water:

Oxygen:
Functions:

• Although plants can produce oxygen on their own, they also need oxygen from the atmosphere. Just as other animals need oxygen to survive, plants also need oxygen for respiration.

• During the day plants take in carbon dioxide and release oxygen, just as at night they take in oxygen and release carbon dioxide.

Deficiency:

• Lack of oxygen causes hypoxia in plants, which results in stunted growth and disturbance in metabolism.

• Hypoxia is mainly caused by excessive rainfall and waterlogging of the soil.

Carbon:
Functions:

• Carbon is very essential for plants because throughout the day plants collect carbon dioxide from the atmosphere.

• Carbon allows plants to grow better, have better respiration systems, and allow plants to break down sugars and store energy.

Deficiency:

• If the supply of carbon fails, the plant's respiration process and photosynthesis process are disrupted.

• In its absence, the growth of the plant is disturbed.

Hydrogen:
Functions:

• H2 helps the plant from seed to seedling, and also helps in the growth of plant stem, and spreading of roots.

• H2 keeps plants fresh, and H2 also helps in stomatal closure.

• H2 may also enhance plant resistance to symbiotic stress through antioxidant mechanisms.

Deficiency:

• Deficiency of H2 causes drought in plants.

• The leaves turn yellow, the tips of the leaves turn brown, the young leaves drop, and the roots rot.

• A lack of H2 can also cause plant death.