The role of macronutrients in plant nutrition

You can ignore the subject of fertilizers and not get into their role in plant development indefinitely, but without this knowledge of the outstanding results in indoor flowering and gardening is nothing to think about.

In the chemical composition of plants almost the entire Mendeleev’s table, about the influence of some substances there is no data yet, but the most important “levers” of control of metabolic processes are studied. The following macronutrients are the most important in root feedings:

  • nitrogen,
  • phosphorus,
  • potassium,
  • magnesium,
  • calcium,
  • sulfur,
  • iron.

Signs of nitrogen deficiency and excess


One of the most important elements for plant nutrition and chlorophyll formation. It participates in the regulation of green mass growth and affects the duration of flowering.

In the absence of

  • Growth slows down
  • Growth slows down
  • Growth slows down
  • Leaves turn yellow because of insufficient chlorophyll production: first at the bottom, since the element is primarily accumulated in young tissues, but gradually the entire green mass begins to suffer

In excess

  • Too rapid growth with the formation of looser tissues
  • Decreased immunity to disease
  • Flowering is delayed or does not happen at all
  • Potassium absorption is impaired
  • Nitrates build up as a result of excessive nitrogen fertilizer application

Signs of phosphorus deficiency and excess


It is necessary in most metabolic processes, is involved in the laying of buds and fruiting, affects the health of the root system and winter-hardiness of the plant.

  • Delayed flowering
  • Delayed flowering
  • Slows down the ripening of fruits and seeds
  • Defective fruits and seeds are formed
  • Leaves unnaturally darken, turning bluish or reddish brown – the process goes from the lower to the younger ones
  • Leaves curl upward
  • Slows down the development of
  • Slows down the development of
  • Slows down the development of
  • Resistance to water scarcity decreases
  • The absorption of potassium, zinc, iron is impaired
  • Leaves turn yellow due to impaired chlorophyll production and become covered with pronounced necrotic spots, then fall off
  • The plant ages quickly
  • The plant ages quickly

signs of potassium deficiency and excess


It participates in the processes of carbohydrate, protein, water metabolism and photosynthesis. It influences the ability of the plant to retain moisture, strengthens tissues and increases resistance to diseases and pests.

  • Leaves take on a twisted, crinkled shape and curl downward
  • Burns and brown spotting on the edges of the leaf plate appear
  • Leaves turn bluish, dull, with a bronze tint
  • The stem becomes thin, loose
  • Slow down plant development and bud formation
  • Exposure to fungal diseases increases
  • The size of the flowers decreases
  • The plant is dropping ovaries
  • Quality and quantity of crops suffer
  • The plant is stretching out
  • The plant is stretching out
  • Leaves become deformed and yellow – the process goes from bottom to top; covered with mosaic spots, wither and fall off
  • New leaves are formed small
  • New leaves are formed small
  • Nitrogen, magnesium, calcium, zinc absorption is impaired
  • The flower stalks are shortening
  • Reduced resistance to fungal diseases and adverse weather conditions

Signs of magnesium deficiency and excess


It is one of the components of chlorophyll, so the process of photosynthesis is impossible without it. The element activates many enzymes and is involved in the synthesis of carbohydrates, proteins, fats and organic acids. Magnesium is also involved in the formation of phytin – this substance is contained in the seeds of plants, it is necessary for metabolic processes during germination.

  • Veins and edges of leaves turn yellow, reddish or purple, large veins remain green
  • Leaves become dome-shaped with curved tips and edges, the edges gradually shrivel up and die off
  • Fruits do not mature
  • Roots die off
  • Calcium, iron, and potassium absorption is impaired
  • Leaves darken, slightly shrinking
  • Young leaves shrivel up

Signs of calcium deficiency and excess


Participates in cell membrane formation, carbohydrate and protein metabolism, chloroplast synthesis and growth. Calcium is required for ammonia nitrogen assimilation and inhibits ammonia release from nitrates.

  • Growth stops
  • Root development is inhibited, formation of root hairs stops, tips are damaged and turn brown
  • The growth point becomes deformed and dies off
  • Leaf margins become irregularly shaped and stained brown
  • Leaves turn yellow, curl or wavy and then die off
  • Buds, flowers and ovaries fall off
  • Necrotic spots appear on fruits
  • Deteriorates the absorption of other nutrients
  • Leaves turn yellow between veins and are covered with light necrotic spots, quickly fall off
  • The absorption of potassium, magnesium, nitrogen and other elements is impaired

Signs of sulfur deficiency and excess


Participates in the synthesis of proteins, some vitamins and amino acids, chlorophyll. It stimulates formation of nitrogen-fixing nodules in legumes.

  • Leaves are pale, but, unlike nitrogen deficiency, hardly fall off; color change occurs from the top to the roots
  • Yields of cruciferous and cereals decrease
  • Leaves become shallower, coarser, a dull green color, and gradually die off
  • Leaf edges curl inward and turn brown, after which the coloration changes to pale yellow or lilac-brown

Signs of iron deficiency and excess


Necessary for the synthesis of chlorophyll, proteins and other processes.

  • Leaves turn pale between veins, gradually turning white all over – the process goes from the top to the roots
  • Inflorescences of herbaceous plants form small and weak
  • The tips of branches and shoots of fruit trees dry out
  • Yields decrease
  • The development of the root system and the above-ground part of the plant stops
  • Young leaves turn yellow between veins, gradually become completely pale, necrotic spots do not appear
  • At particularly high concentrations of iron, leaves die off and fall off without any change in color or shape
  • The absorption of phosphorus, manganese and other elements is deteriorating

Since a deficiency or excess of one element can affect the plant’s ability to assimilate other elements, it is not always easy to correctly determine the cause of the painful condition and correct it. When fertilising, it is advisable to strictly follow the manufacturer’s instructions: you can always make up the deficiency, but you can’t neutralise the excessive dosage.