About the importance of trace elements or what is lacking in a plant? Nutrients and their role in plant life Nutrients necessary for plants for life processes.

In such a situation, you need to carefully look at the emerging unfavorable signs of plant starvation and urgently carry out targeted feeding.

If the upper leaves turn yellow, then the plant clearly lacks calcium. Or, conversely, its excessive amount. This phenomenon can also be observed if you water the garden with hard water.

Yellowing and falling of the lower leaves indicates that you need to reduce watering. In this way, the plant responds to increased moisture in the substrate.

Sometimes green pets develop chlorosis. At the same time, the leaves turn pale and prematurely acquire a yellow color. This disease is usually accompanied by the death of shoots. Such phenomena develop in plants under conditions of a lack of iron compounds in the soil. Of tree and shrub crops, apple, plum, pear and raspberry show increased sensitivity to glandular starvation. In this case, spraying the affected plants with a solution of ferrous sulfate will help to quickly restore mineral nutrition. For its preparation, 5 g of powder is diluted in 10 liters of water.

Weak chlorosis of young leaves may signal the onset of copper starvation. In parallel with this, the growth of apical buds stops too early in fruit trees.

Suspension of plant growth and development is a symptom of boron starvation. In addition, heart rot can develop in fruit crops. A solution of boric acid can help plants. It must be applied in a non-root way - by spraying.

If a marginal leaf burn is noticed, then it is urgent to feed the plants with potash fertilizers. At the same time, potassium sulfate, which does not contain chlorine at all, will be the most suitable fertilizer for fruit and berry crops. Ash can also be a lifesaver - it also lacks chlorine and is especially effective if the site has acidic soils.

Pale leaves with a reddish or yellowish tint are a symptom of nitrogen deficiency. Nitrogen top dressing is applied superficially or by embedding fertilizer granules to a shallow depth. The soil must be sufficiently moist. This must be done immediately at the first symptoms.

The appearance of brown spots on the leaves between the veins indicates a lack of magnesium. Magnesium sulfate is effective in this case. It is only necessary to remember that the more acidic the substrate, the more difficult it is for plants to absorb magnesium, and the higher the doses of this fertilizer should be.

Like these ones signs of plant starvation can be seen in the garden. And this is not so bad, because in this way green pets give us a signal and ask for help.

Nutrient deficiency

Everyone knows that nutritional deficiencies negatively affects the growth and development of plants, which naturally affects the quantity and quality of the harvested crop. Today I will tell you about how our most common favorite vegetables react to the lack of basic nutrients - nitrogen, phosphorus, potassium. And also about what to do if you, by external signs, have determined the lack of one or another element.

Nitrogen deficiency.

It manifests itself most strongly in the presence of high soil moisture, especially when it rains for a long time, as well as during drought or prolonged cold weather. With a lack of nitrogen, the leaves of plants become small, pale green in color with a yellowish tinge, and the fruits are crushed and, as a rule, fall off prematurely.

Consider the specific reaction of a vegetable plant to a lack of nitrogen:

Carrots - small leaves, grow very slowly, turn yellow and die.

Onions - weakly growing, narrow short leaves of a light green color, often begin to turn red from the tip of the leaf.

Cabbage - stunted, becomes dwarf, small leaves, first pale green with a yellowish tinge, and later turn orange, dry quickly and soon fall off.

Beets - languishes, lags behind in growth, has upright, thin petioles of leaves. Leaf color ranges from pale green to yellow-red.

Tomatoes - overall growth is strongly suppressed. Small leaves become light green with a purple or yellow tinge along the veins. Old leaves die off very quickly. The stems are hard and thin. The roots darken and soon die off. Nitrogen-deficient tomatoes have woody, small fruits that are pale green at first, then turn bright red, and often fall off prematurely.

Cucumbers - lag behind in growth, have small leaves that are pale green with a yellow tint. Especially quickly the lower leaves droop and turn yellow. The stems are fibrous, thin, more rigid, with a pale color. Cucumbers develop with a lack of nitrogen very, very slowly.

Nitrogen the most widely used macronutrient, the most important building material of plants, increases the green (vegetative) mass of plants, and as a result yields. Participates in the formation of proteins. As an important component, it is found in nucleoproteins and nucleic acids, it is part of the chlorophyll molecule, vitamins (for example, thiamine), and alkaloids.

Among all mineral fertilizers, nitrogen fertilizers are the most dangerous in case of overdose: excess nitrogen accumulates in vegetables in the form of nitrates and nitrites, which are harmful to human health. Nitrates in plants accumulate not only with an excess of nitrogen, but also with a lack of molybdenum and iron, which contribute to the reduction of nitrate nitrogen (NO 3) to ammonia (NH 4).

Signs of nitrogen deficiency: inhibition of plant growth; in vegetable crops, old leaves acquire a yellow-green color; in fruit leaves, they additionally turn red, after fruit set, some of them crumble, and the rest grow small, with dense pulp.

Phosphorus

Phosphorus one of the main macro-components that increase productivity and product quality. Due to its activating effect, phosphorus plays a decisive role in photosynthesis, energy and hydrogen transfer (respiration), transfer of hereditary properties, formation of cell membranes, accelerates the transition of plants to the reproductive phase. It has a positive effect on the generative organs of the plant; it is especially important for crops whose commodity organs are seeds and fruits (cereals, fruits, berries, most vegetables).

Phosphorus Deficiency Signs: vegetable plants stop growing, leaves and young stems turn dark green to blue-green; in fruit , the stems and individual leaves become bluish-pink or acquire a brown-green color.

Potassium

Potassium is the main component that increases the yield, quality and resistance of plants. It has a positive effect on the resistance of plants to drought, low temperatures, pests and fungal diseases, allows plants to use water more economically and productively, enhances the transport of substances in the plant and the development of the root system. It is very important that potassium intensifies the synthesis and transport to the reproductive organs of plants. Due to the increased synthesis of vitamin C, the fruits acquire a brighter color and aroma, and are stored longer.

Signs of potassium deficiency: turgor decreases in plants, leaves wither and droop (become corrugated). Potassium deficiency starts from the edges of the leaf light green spots are formed, which turn brown with increased starvation "marginal burn".

Calcium

Calcium is involved in water, carbohydrate and nitrogen metabolism, neutralizes the action of organic acids, regulates metabolic processes, regulates the cell's water balance and physiological balance, is necessary for the plant to form nucleic acids, photosynthesis and energy metabolism are closely related to it.

The most important role of calcium is participation in the construction of cell membranes and maintaining their structural organization, membrane potential. By supporting the structure of the cell membranes of fruits and vegetables, calcium prevents premature aging and, as a result, improves the ability to store and transport fruits.

Signs of calcium deficiency in vegetable crops, they are most noticeable on young leaves, which become chlorotic (formation of light yellow spots); old , on the contrary, acquire a dark green color and increase in size. In fruit trees, young leaves become smaller, curl, pale bluish spots form on some, growth buds often die and fall off, young roots turn brown. In some varieties of apple trees, fruits are affected by bitter pitting and brown spotting of the peel - their manifestation increases in wet, cold weather, when the movement of calcium into the fruits is delayed.

Magnesium

Magnesium - its deficiency is especially often observed on light soils. It influences all processes in plant cells where chemical energy is transferred and accumulated (photosynthesis, respiration, glycolysis, etc.). Together with calcium, magnesium is involved in the construction of pectin substances of cell walls. More than 300 enzymes are activated by magnesium due to its specific binding into complexes. It has a positive effect on the transport and absorption of phosphorus.

Signs of magnesium deficiency: interveinal chlorosis in old leaves, leaves harden and become brittle (dry and fall off prematurely). Signs of starvation are first seen at the base of the current year's shoot, then spread to the top of the shoot, where a few thin dark green leaves remain. In cherries and some apple cultivars, interveinal chlorosis begins in the middle of the leaf (leaves between the veins turn purplish red). In cherries and pears, the spots on the leaves are often almost black in color - the fruits ripen slowly and are usually unsuitable for storage.

Sulfur

Sulfur is involved in the metabolism and transport of substances, in the general processes of ionic equilibrium in plant cells. Included in the composition of proteins, being one of the initial products for the biosynthesis of amino acids.

Sulfur Deficiency Signs: leaves become light green in color, and later yellow, partially with a reddish tint. Unlike nitrogen deficiency (which first appears on older leaves), sulfur deficiency appears first on young leaves. The stems become thin, brittle, stiff and stiff. In plants of the cabbage family, the leaves become narrow and elongated.

Iron

Iron is actively involved in metabolic processes, activates respiration, affects the formation of chlorophyll. Iron is part of the enzymes involved primarily in redox reactions. Iron enters the plant in the form of Fe 2+ and Fe 3+ ions, as well as in small amounts in the form of molecules of chelate compounds and is concentrated (about 80%) in the chloroplast protein, i.e. in the leaves.

Signs of iron deficiency: plant growth is delayed, young leaves become chlorotic. In acute deficiency, the leaves turn white, and only the leaf veins at the edges remain green. From old leaves to young iron does not move. Fruit crops often suffer from iron deficiency, especially when grown on carbonate or overcalcified soils - the so-called calcareous chlorosis occurs. Trees with highly developed chlorosis do not bloom well, the fruit yield is sharply reduced.

Manganese

Manganese is involved in metabolic reactions in plant cells, in the processes of photosynthesis, the formation of chlorophyll, protein metabolism, the synthesis of vitamin C (ascorbic acid), and enhances the accumulation of sugar.

Most soils contain a sufficient amount of absorbable manganese, however, its deficiency can be observed on light (sandy) soils, where it is subject to strong leaching from the upper soil layers. Manganese deficiency can also appear on high-humus and podzolic soils after their liming.

Manganese Deficiency Signs plants are different. In potatoes, the surface of the leaf becomes uneven the veins remain below, and the interveinal space protrudes. In a cucumber, young leaves take on a light green color, and yellowish along the edges. Later, the process covers the entire leaf blade, and the veins remain bright green. In table beets, the leaves turn dark red. On the youngest leaves of plants, pale blue spots appear between the leaf vessels.

Zinc

Zinc is an important biogenic element present in living organisms, it performs versatile functions in the plant body - it is widely involved in redox processes, regulating the oxidation of substrates and the transfer of electrons along the phosphorylating respiratory chain, activates at least 13 enzymes, participates in the biosynthesis of growth stimulants. The intensity of absorption of zinc by plants from the soil depends on its acidity on neutral and alkaline soils, it is negligible. In such soils, and also with abundant fertilization with phosphorus, zinc is strongly bound in the upper horizons, as a result of which zinc starvation can occur, especially in cultures with deep roots, where zinc does not get. The decrease in the amount of assimilated zinc in the soil is explained by the formation of sparingly soluble phosphates of this element. Zinc deficiency reduces the absorption of ammonium nitrogen. With a lack of zinc in plants, the accumulation of sugars decreases, the amount of organic acids increases, protein synthesis is disturbed, while the content of non-protein nitrogen compounds - amides and amino acids increases.

Signs of zinc deficiency: small-leaved (lanceolate) and rosette. Vegetables show spotting of the upper leaves, which become yellowish, with a bronze tint. The tomato produces abnormally small chlorotic leaves resembling the small leaves of fruit trees.

Copper

Copper is part of enzymes, increases the intensity of respiration and photosynthesis, affects protein and carbohydrate metabolism. The main value of copper is participation in the formation of redox enzymes, it is present in the active center of the metal-protein complex (acts as an activator of biochemical processes), promotes protein synthesis, affecting nitrogen metabolism in the plant. Copper stimulates the synthesis of carbohydrates, improves the supply of nitrogen and magnesium to plants, participates in auxin and nucleic metabolism, and lignin biosynthesis.

Signs of Copper Deficiency Cereals are indicator plants for copper deficiency. They have whitening of the tips of young leaves and twisting them, followed by wilting and dying off. There is an ugliness in the development of the ear.

In fruit crops, young shoots die off, marginal chlorosis and necrosis are noted in the leaves, the transition of plants to the generative phase (flowering and fruit formation) is sharply delayed, the leaves fall off; the tips of the shoots die off and bend down (there is a "withering of the tips" in the apple tree). Copper starvation increases with a high content of heavy metals (Mn, Fe, Zn) in the soil solution due to ion antagonism.

Bor

Boron is not found in nature in a free state. In plants, it participates in the formation of cellular structures and normal differentiation of tissues, gives them strength. Boron improves nutrient absorption and transport of carbohydrates from leaves to roots and reproductive organs.

Of all the trace elements, boron has the strongest effect on plant development and crop quality. The need for boron in different crops is different dicot plants (almost all vegetables and fruits) absorb approximately 10 times more boron than monocots (cereals). Especially a lot of it accumulates in the pulp of the fruit. Boric starvation intensifies with drought and a change in the reaction of the soil environment to the alkaline side (liming).

Boron deficiency symptoms: in potatoes, the growth of the plant is delayed, the growth point is inhibited, the internodes become shortened, and the petioles of the leaves are brittle. Tubers are formed small, often fissured, darkening of the vascular ring develops in the lower part of the tuber. Cauliflower inflorescences darken and blacken, a hollow with blackened edges forms in the stem. Root crops develop heart rot. The growth point of the tomato stem turns black, and new leaves begin to grow in the lower part, the petioles of young leaves become brittle (brown spots of dead tissue form on the fruits).

In fruit trees, at the top of the shoot, the leaves acquire a bluish tint, wrinkle, are brittle and necrotic at the edges. At the same time, there is an increased growth of axillary buds. Fruiting trees often develop necrosis of the fruit pulp.

Molybdenum

Molybdenum is a component of some enzymes (aldehyde oxidase, hydrogenase, nitrate reductase). It catalyzes the transition of nitrates to nitrites in plants and is present in all organs, including roots, participates in the fixation of molecular nitrogen by nodule bacteria from the genus Rhizobium, takes part in phosphorus and protein metabolism, and also participates in the formation of pectin. The lack of molybdenum leads to the accumulation of soluble nitrogen-containing compounds and inhibition of the formation of organophosphorus components in the plant. The acidic reaction of soils greatly reduces its mobility and, consequently, its absorption by plants. On peaty soils (where there is a lot of undecomposed organic matter), molybdenum is strongly bound and inaccessible to plants. Unlike other trace elements, molybdenum can be accumulated in plants in fairly large quantities without causing a toxic effect. Molybdenum starvation can cause a decrease in the formation of ascorbic acid, which entails a decrease in the intensity of photosynthesis as a result of a decrease in chlorophyll regeneration.

Signs of a Molybdenum Deficiency especially noticeable in cabbage (cauliflower) the leaves are twisted, wrinkled, take on a lanceolate shape, their tissue is thin and transparent, while the color of the leaves becomes dirty green. The first and second pairs of true tomato leaves turn yellow, curl upwards: chlorosis spreads between the veins to the entire leaf blade. In cucumber, chlorosis is observed along the edges of the leaves. In legumes and fruit crops, light green spots appear on the leaves, as with a lack of nitrogen.

Chlorine

Chlorine chlorine is necessary for plants in a small amount; together with alkaline and alkaline earth ions, it positively affects the water content of tissues and the swelling of cell protoplasm. This element activates enzymes that carry out photolysis reactions during photosynthesis, but only in certain plant species the need for this element is high. Different plants respond differently to the concentration of chlorine in the soil solution in practice, you have to deal more with an excess of chlorine, especially in dry conditions. Such crops as radishes, spinach, chard, celery, sugar beets are positively related to chlorine. Chlorophobic plants that react negatively to an increased content of chlorine in the soil include: tobacco, grapes, pumpkin, beans, potatoes, tomatoes, fruit and berry crops.

Sign of chlorine deficiency, observed extremely rarely, is leaf chlorosis.

Sodium

Sodium is one of the elements that are conditionally necessary for plants. In chemical and physiological terms, sodium is close to potassium. Potassium can almost always replace sodium, but sodium itself is not replaced. There are a number of enzymes that are activated by sodium, but to a much lesser extent than by potassium. Some plants can absorb significant amounts of sodium, while others have a very small ability to absorb it. In addition, in sodium-phobic plants, the supply of sodium from the root to the aboveground organs is limited (for example, in beans). Spinach, tomato are classified as natriophiles, they respond positively to sodium, especially when they are not sufficiently supplied with potassium. In natriophilic plants, sodium improves water balance.

Silicon

Silicon is one of the elements that are conditionally necessary for plants. It is deposited in the cells in an amorphous form (in the form of opal) and binds in the plant organism to the silicate-galactose complex and thus affects the metabolism, strengthens the cell walls, normalizes the intake and distribution of manganese in the plant, eliminating its toxic effect in case of excess content.

In some crops, under the influence of silicon, enhanced growth occurs, in others, resistance to powdery mildew increases. In agriculture, silicon finds practical application in the cultivation of rice, where, with a lack of silicon, grain yields can be reduced by 50%.

Cobalt

Cobalt is one of the elements that are conditionally necessary for plants. Necessary for the binding of molecular nitrogen by nodule bacteria, various microorganisms, is a component of vitamin B 12. It activates the nitrogenase enzyme system in nodules, participates in the biosynthesis of leghemoglobin, also participates in oxidative processes and activates enolase and kinase enzymes in the process of pyruvic acid conversion.

Signs of Cobalt Deficiency: poor plant growth (can be partially corrected by the use of ammonium or nitrate nitrogen. Cobalt deficiency (paired with iodine) in pasture grasses or hay meadows is the cause of frequent diseases in cattle.

Titanium

Titanium is part of the enzymes that activate the metabolic processes in the plant during its growth and development, intensify photosynthesis and absorption of nutrients from the soil. The main significance of titanium in the life of plants is the stimulation of the process of pollination, fertilization and fruit set, the acceleration of their growth, and as a result, the beginning of harvesting. Strengthens the immune system of plants - increases resistance to fungal and bacterial diseases.

Plants are able to absorb from the environment almost all elements of the periodic system of D.I. Mendeleev. Moreover, many elements scattered in the earth's crust accumulate in plants in significant quantities.

Nutrients are called substances necessary for the life of the body. An element is considered essential if its absence prevents the plant from completing its life cycle; the lack of an element causes specific disturbances in the vital activity of the plant, which are prevented or eliminated by the introduction of this element; the element is directly involved in the processes of transformation of substances and energy, and does not act indirectly on the plant.

The need for elements can only be established when growing plants on artificial nutrient media - in water and sand cultures. To do this, use distilled water or chemically pure quartz sand, chemically pure salts, chemically resistant vessels and utensils for preparing and storing solutions.

The most accurate vegetation experiments have established that the elements necessary for higher plants (except for 45% carbon, 6.5% hydrogen and 42% oxygen absorbed in the process of air nutrition) include the following:

macroelements, the content of which ranges from tens to hundredths of a percent: nitrogen, phosphorus, sulfur, potassium, calcium, magnesium;

trace elements, the content of which ranges from thousandths to hundred thousandths of a percent: iron‚ manganese‚ copper‚ zinc‚ boron‚ molybdenum.

There are also elements that enhance the growth of only certain groups of plants. For the growth of some plants of saline soils (halophytes), sodium is useful. The need for sodium is manifested in C 4 and CAM plants. In these plants, the need for sodium for the regeneration of PEP during carboxylation was shown. The lack of sodium in these plants leads to chlorosis and necrosis, and also inhibits the development of the flower. Many C3 plants also need sodium. This element has been shown to improve stretch growth and perform an osmoregulatory function similar to potassium. Sodium has a beneficial effect on the growth of sugar beets.

Silicon is essential for the growth of diatoms. It improves the growth of some cereals such as rice and corn. Silicon increases the resistance of plants against lodging, as it is part of the cell walls. Horsetails need silicon to go through their life cycle. However, other species also accumulate enough silicon and respond with an increase in growth rates and productivity when silicon is introduced. In the hydrogenated form of SiO 2, silicon accumulates in the endoplasmic reticulum, cell walls, and in intercellular spaces. It can also form complexes with polyphenols and in this form, instead of lignin, it serves to strengthen cell walls.

The need for vanadium for Scenedesmus (green unicellular algae) has been shown, and this is a very specific need, since vanadium is not needed even for the growth of chlorella.

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MOSCOW - 2006
Published by decision of the Department of Botany with the basics of agriculture. Klimachev D.A. Lectures on plant physiology. M.: MGOU Publishing House, 2006. - 282 p.

And main lines of research
In the biosphere, the dominant position is occupied by the plant world, the basis of life on our planet. The plant has a unique property - the ability to accumulate the energy of light in organic matter.

The nature and functions of the main chemical components of the plant cell
The earth's crust and atmosphere contains more than a hundred chemical elements. Of all these elements, only a limited number have been selected in the course of evolution to form a complex, highly organized

Elemental composition of plants
Nitrogen - is a part of proteins, nucleic acids, phospholipids, porphyrins‚ cytochromes, coenzymes (NAD, NADP). Enters plants in the form of NO3-, NO2

Carbohydrates
Carbohydrates are complex organic compounds whose molecules are built from atoms of three chemical elements: carbon, oxygen, hydrogen. Carbohydrates are the main source of energy for living systems. Cr

plant pigments
Pigments are high-molecular natural colored compounds. Of the several hundred pigments that exist in nature, the most important from a biological point of view are metalloporphyrins and flavins.

Phytohormones
It is known that the life of animals is controlled by the nervous system and hormones, but not everyone knows that the life of plants is also controlled by hormones, which are called phytohormones. They regulate the

Phytoalexins
Phytoalexins are low molecular weight antibiotic substances of higher plants that occur in the plant in response to contact with phytopathogens; when rapidly reaching antimicrobial concentrations, they can

Cell wall
The cell membrane gives mechanical strength to plant cells and tissues, protects the protoplasmic membrane from destruction under the influence of hydrostatic pressure developed inside the cell.

Vacuole
Vacuole - a cavity filled with cell sap and surrounded by a membrane (tonoplast). A young cell usually has several small vacuoles (pro-vacuoles). As the cell grows, it produces

plastids
There are three types of plastids: chloroplasts are green, chromoplasts are orange, and leukoplasts are colorless. The size of chloroplasts ranges from 4 to 10 microns. The number of chloroplasts is usually

Organs, tissues and functional systems of higher plants
The main feature of living organisms is that they are open systems that exchange energy, matter and energy with the environment.

Regulation of enzyme activity
Isosteric regulation of enzyme activity is carried out at the level of their catalytic centers. The reactivity and direction of the work of the catalytic center primarily depend on the

Genetic regulation system
Genetic regulation includes regulation at the level of replication, transcription, processing, and translation. The molecular mechanisms of regulation are the same here (pH‚ nones, modification of molecules, proteins-regulators

Membrane regulation
Membrane regulation occurs through shifts in membrane transport, binding or release of enzymes and regulatory proteins, and by altering the activity of membrane enzymes. All fun

Trophic regulation
Interaction with the help of nutrients is the simplest way of communication between cells, tissues and organs. In plants, roots and other heterotrophic organs depend on the intake of assimilates‚ o

Electrophysiological regulation
Plants, unlike animals, do not have a nervous system. However, the electrophysiological interactions of cells, tissues, and organs play an essential role in the coordination of functional

Auxins
Some of the earliest experiments on growth regulation in plants were carried out by Charles Darwin and his son Francis and are set forth in The Power of Movement in Plants, published in 1881 by Darwin.

Cytokinins
Substances necessary for the induction of plant cell division are called cytokinins. For the first time, pure cell division factor has been isolated from an autoclaved sample of sperm DNA.

Gibberellins
The Japanese researcher E. Kurosawa in 1926 found that the culture fluid of the phytopathogenic fungus Gibberella fujikuroi contains a chemical substance that promotes strong elongation of the stem

Abscisins
In 1961, V. Lew and H. Carnes isolated a substance in crystalline form from dry mature cotton bolls, which accelerates leaf fall, and called it abscisin (from the English abscission - separation, opa

Brassinosteroids
For the first time in the pollen of rapeseed and alder, substances with growth-regulating activity and called brassins were found. In 1979, the active principle (brassinolide) was isolated and its chemistry determined.

Thermodynamic foundations of plant water metabolism
The introduction of the concepts of thermodynamics into plant physiology made it possible to mathematically describe and explain the causes that cause both cell water exchange and water transport in the soil-plant-a system.

Absorption and movement of water
The soil is the source of water for plants. The amount of water available to a plant is determined by its state in the soil. Forms of soil moisture: 1. Gravitational water - fills

transpiration
The basis of water consumption by a plant organism is the physical process of evaporation - the transition of water from a liquid state to a vapor state, which occurs as a result of contact between plant organs.

Physiology of stomatal movements
The degree of opening of the stomata depends on the light intensity, water content of the leaf tissues, CO2 concentration in the intercellular spaces, air temperature, and other factors. Depending on the factor,

Ways to reduce the intensity of transpiration
A promising way to reduce the level of transpiration is the use of antitranspirants. According to the mechanism of action, they can be divided into two groups: substances that cause the stomata to close; thing

History of photosynthesis
In the old days, the doctor had to know botany, because many medicines were prepared from plants. It is not surprising that doctors often grew plants, conducted various experiments with them.

The leaf as an organ of photosynthesis
In the process of plant evolution, a specialized organ of photosynthesis, the leaf, was formed. Its adaptation to photosynthesis proceeded in two directions: perhaps more complete absorption and storage of radiant

Chloroplasts and photosynthetic pigments
The leaf of a plant is an organ that provides the conditions for the photosynthetic process to proceed. Functionally, photosynthesis is confined to specialized organelles - chloroplasts. higher chloroplasts

chlorophylls
Currently, several different forms of chlorophyll are known, which are denoted by Latin letters. Chloroplasts of higher plants contain chlorophyll a and chlorophyll b. They were identified by the Russian

Carotenoids
Carotenoids are fat-soluble pigments that are yellow, orange, and red. They are part of the chloroplasts and chromoplasts of non-green parts of plants (flowers, fruits, root crops). In green l

Organization and functioning of pigment systems
Chloroplast pigments are combined into functional complexes - pigment systems in which the reaction center - chlorophyll a, which performs photosensitization, is associated with energy transfer processes with

Cyclic and non-cyclic photosynthetic phosphorylation
Photosynthetic phosphorylation, i.e., the formation of ATP in chloroplasts during reactions activated by light, can be carried out in cyclic and non-cyclic ways. Cyclic photophospho

Dark phase of photosynthesis
Products of the light phase of photosynthesis ATP and NADP. H2 is used in the dark phase to restore CO2 to carbohydrate levels. Recovery reactions take place

C4 pathway of photosynthesis
The path of assimilation of CO2, established by M. Calvin, is the main one. But there is a large group of plants, including more than 500 species of angiosperms, in which the primary products are fixed

CAM metabolism
The Hatch and Slack cycle was also found in succulent plants (from the genera Crassula, Bryophyllum, etc.). But if in C4 plants cooperation is achieved due to the spatial separation of two qi

photorespiration
Photorespiration is the light-induced uptake of oxygen and release of CO2, which is observed only in plant cells containing chloroplasts. The chemistry of this process is

Saprotrophs
At present, fungi are classified as an independent kingdom, but many aspects of the physiology of fungi are close to plant physiology. Apparently, similar mechanisms underlie their heterotrophic

carnivorous plants
Currently, over 400 species of angiosperms are known that catch small insects and other organisms, digest their prey and use its decomposition products as an additional source of food.

glycolysis
Glycolysis is the process of generating energy in the cell, occurring without the absorption of O2 and the release of CO2. Therefore, its speed is difficult to measure. The main function of glycolysis along with

Electron transport chain
In the considered reactions of the Krebs cycle and in glycolysis, molecular oxygen does not participate. The need for oxygen arises from the oxidation of reduced carriers NADH2 and FADH2

Oxidative phosphorylation
The main feature of the inner mitochondrial membrane is the presence of electron carrier proteins in it. This membrane is impermeable to hydrogen ions, so the transfer of the latter through the membrane

Pentose phosphate breakdown of glucose
The pentose phosphate cycle, or hexose monophosphate shunt, is often referred to as apotomic oxidation, in contrast to the glycolytic cycle, referred to as dichotomous (the breakdown of a hexose into two trioses). special

Fats and proteins as a respiratory substrate
Spare fats are spent on the respiration of seedlings that develop from seeds rich in fats. The use of fats begins with their hydrolytic cleavage by lipase into glycerol and fatty acids, which

Signs of plant starvation
In many cases, with a lack of mineral nutrients, characteristic symptoms appear in plants. In some cases, these signs of starvation can help establish the functions of this element, and

Ion antagonism
For the normal life of both plant and animal organisms in their environment, there must be a certain ratio of various cations. Pure solutions of salts of any one

Absorption of minerals
The root system of plants absorbs both water and nutrients from the soil. Both of these processes are interrelated, but are carried out on the basis of different mechanisms. Numerous studies have shown

Ionic transport in a plant
Depending on the level of organization of the process, three types of transport of substances in a plant are distinguished: intracellular, near (inside the organ) and distant (between organs). Intracellular

Radial movement of ions in the root
Through metabolic processes and diffusion, ions enter the cell walls of the rhizodermis, and then through the cortical parenchyma are directed to the conductive bundles. Up to the inner layer of the endoderm cortex, it is possible

Upward transport of ions in a plant
The ascending current of ions is carried out mainly through the vessels of the xylem, which are devoid of living content and are an integral part of the plant apoplast. Mechanism of xylem transport - mass t

Ion uptake by leaf cells
The conducting system accounts for about 1/4 of the leaf tissue volume. The total length of the branching of the conductive bundles in 1 cm of the leaf blade reaches 1 m. Such saturation of the leaf tissues is conductive

The outflow of ions from the leaves
Almost all elements, with the exception of calcium and boron, can flow from leaves that have reached maturity and begin to age. Among the cations in phloem exudates, the dominant place belongs to potassium, on

Nitrogen plant nutrition
The main assimilable forms of nitrogen for higher plants are ammonium and nitrate ions. The most complete question of the use of nitrate and ammonia nitrogen by plants was developed by Academician D.N.P

Assimilation of nitrate nitrogen
Nitrogen is present in organic compounds only in reduced form. Therefore, the inclusion of nitrates in the metabolism begins with their reduction, which can be carried out both in the roots and in

Assimilation of ammonia
Ammonia formed during the reduction of nitrates or molecular nitrogen, as well as entered into the plant during ammonium nutrition, is further absorbed as a result of reductive amination of ket.

Accumulation of nitrates in plants
The rate of absorption of nitrate nitrogen can often exceed the rate of its metabolism. This is due to the fact that the centuries-old evolution of plants proceeded under conditions of nitrogen deficiency and systems were developed that

Cellular bases of growth and development
The basis for the growth of tissues, organs and the whole plant is the formation and growth of meristematic tissue cells. There are apical, lateral and intercalary (intercalary) meristems. Apical meris

The law of the long period of growth
The growth rate (linear, mass) in the ontogeny of a cell, tissue, any organ, and plant as a whole is not constant and can be expressed as a sigmoid curve (Fig. 26). For the first time, this pattern of growth was

Hormonal regulation of plant growth and development
The multicomponent hormonal system is involved in the control of growth and shaping processes of plants, in the implementation of the genetic program of growth and development. In ontogeny in some parts

Effect of phytohormones on plant growth and morphogenesis
Germination of seeds. In the swelling seed, the embryo is the center of formation or release of gibberellins, cytokinins, and auxins from the bound (conjugated) state. From s

The use of phytohormones and physiologically active substances
The study of the role of individual groups of phytohormones in the regulation of plant growth and development has determined the possibility of using these compounds, their synthetic analogues and other physiologically active substances.

Physiology of seed dormancy
Seed dormancy refers to the final phase of the embryonic period of ontogeny. The main biological process observed during the organic dormancy of seeds is their physiological ripening‚ following

Processes that occur during seed germination
During seed germination, the following phases are distinguished. Water absorption - dry seeds at rest absorb water from the air or some substrate before the critical

dormancy of plants
Plant growth is not a continuous process. In most plants, from time to time there are periods of a sharp slowdown or even an almost complete suspension of growth processes - dormant periods.

Physiology of plant aging
The stage of aging (old age and dying off) is the period from the complete cessation of fruiting to the natural death of the plant. Aging is a period of natural weakening of vital processes, from

Autumn leaf color and leaf fall
Deciduous forests and orchards change color in autumn. In place of the monotonous summer coloring, a wide variety of bright colors appears. The leaves of hornbeams, maples and birches turn light yellow,

Influence of microorganisms on plant growth
Many soil microorganisms have the ability to stimulate plant growth. Beneficial bacteria can exert their influence directly by supplying plants with fixed nitrogen, chelating

plant movements
Plants, unlike animals, are attached to their habitat and cannot move. However, they also have movement. Plant movement is a change in the position of plant organs in space.

Phototropisms
Among the factors that cause the manifestation of tropisms, light was the first to be noticed by man. In ancient literary sources, changes in the position of plant organs were described.

Geotropisms
Along with light, plants are influenced by gravity, which determines the position of plants in space. The inherent ability of all plants to perceive the earth's gravity and respond to it

Cold tolerance of plants
Plant resistance to low temperatures is divided into cold resistance and frost resistance. Cold resistance is understood as the ability of plants to endure positive temperatures somewhat in

Frost resistance of plants
Frost resistance - the ability of plants to tolerate temperatures below 0 ° C, low negative temperatures. Frost-resistant plants are able to prevent or reduce the effect of low

Winter hardiness of plants
The direct effect of frost on cells is not the only danger that threatens perennial herbaceous and woody crops, winter plants during the winter. In addition to the direct action of frost

The effect on plants of excess moisture in the soil
Permanent or temporary waterlogging is typical for many regions of the globe. It is also often observed during irrigation, especially carried out by flooding. Excess water in the soil can

Drought tolerance of plants
Droughts have become a common occurrence for many regions of Russia and the CIS countries. A drought is a long rainless period accompanied by a decrease in the relative humidity of the air, soil moisture and

The effect on plants of lack of moisture
The lack of water in plant tissues occurs as a result of its excess consumption for transpiration before entering from the soil. This is often observed in hot sunny weather towards the middle of the day. Wherein

Physiological features of drought resistance
The ability of plants to tolerate insufficient moisture supply is a complex property. It is determined by the ability of plants to delay a dangerous decrease in the water content of the protoplasm (avoidance of

Heat resistance of plants
Heat resistance (heat tolerance) - the ability of plants to endure the action of high temperatures, overheating. This is a genetically determined trait. According to heat resistance, two groups are distinguished

Salt tolerance of plants
Over the past 50 years, the level of the World Ocean has risen by 10 cm. This trend, according to scientists' predictions, will continue further. The consequence of this is an increasing scarcity of fresh water, and up to

Basic terms and concepts
A vector is a self-replicating DNA molecule (for example, a bacterial plasmid) used in genetic engineering for gene transfer. vir genes

From Agrobacterium tumefaciens
The soil bacterium Agrobacterium tumefaciens is a phytopathogen that transforms plant cells during its life cycle. This transformation leads to the formation of a crown gall - o

Vector systems based on Ti-plasmids
The easiest way to use the natural ability of Ti-plasmids to genetically transform plants involves embedding the nucleotide sequence of interest to the researcher into T-DNA

Physical Methods for Gene Transfer to Plant Cells
Agrobacterium tumefaciens gene transfer systems only work effectively for some plant species. In particular, monocots, including major cereals (rice,

Microparticle bombardment
Microparticle bombardment, or biolisting, is the most promising method for introducing DNA into plant cells. Gold or tungsten spherical particles with a diameter of 0.4-1.2 microns cover DNA, o

Viruses and herbicides
Insect-Resistant Plants If cereals could be genetically engineered to produce functional insecticides, we would have

Impact and aging
Unlike most animals, plants cannot physically protect themselves from the adverse effects of the environment: high light, ultraviolet radiation, high temperatures.

Flower color change
Florists are always trying to create plants whose flowers have a more attractive appearance and are better preserved after they are cut. Using traditional crossbreeding methods

Change in the nutritional value of plants
Over the years, agronomists and breeders have made great strides in improving the quality and increasing yields of a wide variety of crops. However, traditional methods for developing new

Plants as bioreactors
Plants provide a large amount of biomass, and growing them is not difficult, so it was reasonable to try to create transgenic plants capable of synthesizing commercially valuable proteins and chemicals.

The role of elements in plant life -

Nitrogen

In the free state, nitrogen is an inert gas, which contains 75.5% of its mass in the atmosphere. However, nitrogen cannot be assimilated in elemental form by plants, with the exception of legumes, which use nitrogen compounds produced by nodule bacteria developing on their roots, which are able to assimilate atmospheric nitrogen and convert it into a form accessible to higher plants.

Nitrogen is absorbed by plants only after it combines with other chemical elements in the form of ammonium and nitrate, the most available forms of nitrogen in the soil. Ammonium, being a reduced form of nitrogen, is easily used in the synthesis of amino acids and proteins when absorbed by plants. The synthesis of amino acids and proteins from reduced forms of nitrogen occurs faster and with less energy than synthesis from nitrates, for the reduction of which to ammonia the plant needs additional energy. However, the nitrate form of nitrogen is safer for plants than ammonia, since high concentrations of ammonia in plant tissues cause their poisoning and death.

Ammonia accumulates in the plant when there is a lack of carbohydrates, which are necessary for the synthesis of amino acids and proteins. Carbohydrate deficiency in plants is usually observed in the initial period of vegetation, when the assimilation surface of the leaves has not yet developed enough to satisfy the plant's need for carbohydrates. Therefore, ammonia nitrogen can be toxic to crops whose seeds are poor in carbohydrates (sugar beet, etc.). With the development of the assimilation surface and the synthesis of carbohydrates, the efficiency of ammonia nutrition increases, and plants absorb ammonia better than nitrates. During the initial period of growth, these crops must be provided with nitrogen in the nitrate form, and crops such as potatoes, whose tubers are rich in carbohydrates, can use nitrogen in the ammonia form.

With a lack of nitrogen, plant growth slows down, the intensity of tillering of cereals and the flowering of fruit and berry crops is weakened, the growing season is shortened, the protein content decreases and the yield decreases.

Phosphorus

The role of phosphorus, which is part of organic compounds, is especially great. A significant part of it is presented in the form of phytin - a typical reserve form of organic phosphorus. Most of this element is found in the reproductive organs and young tissues of plants, where intensive synthesis processes take place. Experiments with labeled (radioactive) phosphorus showed that there is several times more of it at the growth points of a plant than in the leaves.

Phosphorus can move from old plant organs to young ones. Phosphorus is especially necessary for young plants, as it promotes the development of the root system, increases the intensity of tillering of grain crops. It has been established that by increasing the content of soluble carbohydrates in the cell sap, phosphorus enhances the winter hardiness of winter crops.

Like nitrogen, phosphorus is one of the important plant nutrients. At the very beginning of growth, the plant experiences an increased need for phosphorus, which is covered by the reserves of this element in the seeds. On soils poor in fertility, young plants, after the consumption of phosphorus from seeds, show signs of phosphorus starvation. Therefore, on soils containing a small amount of mobile phosphorus, it is recommended to carry out row-by-row application of granular superphosphate simultaneously with sowing.

Phosphorus, unlike nitrogen, accelerates the development of crops, stimulates the processes of fertilization, the formation and ripening of fruits.

The main source of phosphorus for plants are salts of orthophosphoric acid, usually called phosphoric. Plant roots absorb phosphorus in the form of anions of this acid. The most accessible for plants are water-soluble monosubstituted salts of orthophosphoric acid: Ca (H 2 PO 4) 2 - H 2 O, KH 2 PO 4 NH 4 H 2 PO 4 NaH 2 PO 4, Mg (H 2 PO 4) 2.

Potassium

With a lack of potassium (despite a sufficient amount of carbohydrates and nitrogen), the movement of carbohydrates is suppressed in plants, the intensity of photosynthesis, nitrate reduction and protein synthesis decreases.

Potassium affects the formation of cell membranes, increases the strength of cereal stems and their resistance to lodging.

Potassium significantly affects the quality of the crop. Its deficiency leads to the frailty of seeds, a decrease in their germination and vitality; plants are easily affected by fungal and bacterial diseases. Potassium improves the shape and taste of potatoes, increases the sugar content in sugar beets, affects not only the color and aroma of strawberries, apples, peaches, grapes, but also the juiciness of oranges, improves the quality of grain, tobacco leaf, vegetable crops, cotton fiber, flax , cannabis. Plants require the greatest amount of potassium during their intensive growth.

Increased demand for potassium nutrition is observed in root crops, vegetable crops, sunflower, buckwheat, and tobacco.

Potassium in the plant is located mainly in the cell sap in the form of cations bound by organic acids, and is easily washed out from plant residues. It is characterized by repeated use (recycling). It easily moves from the old tissues of the plant, where it has already been used, to the young ones.

The lack of potassium, as well as its excess, adversely affects the quantity of the crop and its quality.

Magnesium

Magnesium ions are adsorptively bound to cell colloids and, along with other cations, maintain ionic equilibrium in plasma; like potassium ions, they help to thicken the plasma, reduce its swelling, and also participate as catalysts in a number of biochemical reactions occurring in the plant. Magnesium activates the activity of many enzymes involved in the formation and conversion of carbohydrates, proteins, organic acids, fats; affects the movement and transformation of phosphorus compounds, fruit formation and seed quality; accelerates the ripening of seeds of grain crops; improves the quality of the crop, the content of fat and carbohydrates in plants, the frost resistance of citrus fruits, fruit and winter crops.

The highest content of magnesium in the vegetative organs of plants is noted during the flowering period. After flowering, the amount of chlorophyll in the plant decreases sharply, and magnesium flows from the leaves and stems to the seeds, where phytin and magnesium phosphate are formed. Therefore, magnesium, like potassium, can move in the plant from one organ to another.

With high yields, crops consume magnesium up to 80 kg per 1 ha. Potatoes, fodder and sugar beets, tobacco, legumes absorb the greatest amount of it.

The most important form for plant nutrition is exchangeable magnesium, which, depending on the type of soil, makes up 5-10% of the total content of this element in the soil.

Calcium

Unlike nitrogen, phosphorus and potassium, which are usually found in young tissues, calcium is contained in significant quantities in old tissues; while it is more in the leaves and stems than in the seeds. So, in pea seeds, calcium is 0.9% of air - dry matter, and in straw - 1.82%

Perennial leguminous grasses consume the largest amount of calcium - about 120 kg of CaO per 1 ha.

A lack of calcium in the field is observed on very acidic, especially sandy, soils and solonetzes, where the intake of calcium into plants is inhibited by hydrogen ions on acidic soils and sodium on solonetzes.

Sulfur

On average, plants contain about 0.2 - 0.4% sulfur from dry matter, or about 10% in ash. Most of all, sulfur is absorbed by crops from the cruciferous family (cabbage, mustard, etc.). Agricultural crops consume the following amount of sulfur (kgha): cereals and potatoes - 10 - 15, sugar beet and legumes - 20 - 30, cabbage - 40 - 70.

Sulfur starvation is most often observed on sandy loamy and sandy soils of the non-chernozem zone poor in organic matter.

Iron

Iron deficiency leads to the breakdown of growth substances (auxins) synthesized by plants. Leaves become light yellow. Iron cannot, like potassium and magnesium, move from old tissues to young ones (i.e., be reused by the plant).

Iron starvation is most often manifested on carbonate and heavily limed soils. Fruit crops and grapes are especially sensitive to iron deficiency. With prolonged iron starvation, their apical shoots die off.

Bor

With a lack of boron, plant growth slows down, growth points of shoots and roots die off, buds do not open, flowers fall off, cells in young tissues disintegrate, cracks appear, plant organs turn black and acquire an irregular shape.

The lack of boron is most often manifested on soils with a neutral and alkaline reaction, as well as on calcareous soils, since calcium interferes with the flow of boron into the plant.

Molybdenum

In plants, molybdenum is part of the enzymes involved in the reduction of nitrates to ammonia. With a lack of molybdenum, nitrates accumulate in plants and nitrogen metabolism is disturbed. Molybdenum improves the calcium nutrition of plants. Due to the ability to change valency (donating an electron, it becomes hexavalent, and attaching it becomes pentavalent), molybdenum is involved in the redox processes occurring in the plant, as well as in the formation of chlorophyll and vitamins, in the exchange of phosphorus compounds and carbohydrates. Molybdenum is of great importance in the fixation of molecular nitrogen by nodule bacteria.

With a lack of molybdenum, plants lag behind in growth and reduce yields, the leaves become pale in color (chlorosis), and as a result of a violation of nitrogen metabolism, they lose turgor.

Molybdenum starvation is most often observed on acidic soils with a pH less than 5.2. Liming increases the mobility of molybdenum in the soil and its consumption by plants. Legumes are especially sensitive to the lack of this element in the soil. Under the influence of molybdenum fertilizers, not only the yield increases, but also the quality of products improves - the content of sugar and vitamins in vegetable crops, protein in leguminous crops, protein in the hay of legumes, etc. increases.

An excess of molybdenum, as well as its deficiency, affects plants negatively - the leaves lose their green color, growth is delayed and the yield of plants is reduced.

Copper

Copper plays an important role in redox processes, having the ability to change from a monovalent form to a divalent one and vice versa. It is a component of a number of oxidative enzymes, increases the intensity of respiration, affects the carbohydrate and protein metabolism of plants. Under the influence of copper, the content of chlorophyll in the plant increases, the process of photosynthesis intensifies, and the resistance of plants to fungal and bacterial diseases increases.

Insufficient provision of plants with copper adversely affects the water-retaining and water-absorbing capacity of plants. Most often, a lack of copper is observed on peat-marsh soils and some soils of light mechanical composition.

At the same time, too high a content of copper available for plants in the soil, as well as other microelements, negatively affects the yield, since the development of roots is disturbed and the intake of iron and manganese into the plant decreases.

Manganese

In addition, manganese is involved in the synthesis of vitamin C and other vitamins; it increases the sugar content in the roots of sugar beets, proteins in cereals.

Manganese starvation is most often observed on carbonate, peat and heavily limed soils.

With a lack of this element, the development of the root system and plant growth slows down, and productivity decreases. Animals fed low manganese diets suffer from weakened tendons and poor bone development. In turn, an excess amount of soluble manganese, observed on strongly acidic soils, can adversely affect plants. The toxic effect of excess manganese is eliminated by liming.

Zinc

Insufficient provision of plants with digestible zinc is observed on gravel, sandy, sandy loamy and carbonate soils. Vineyards, citrus and fruit trees in the arid regions of the country on alkaline soils are especially affected by a lack of zinc. With prolonged zinc starvation, dry tops are observed in fruit trees - the death of the upper branches. Of the field crops, corn, cotton, soybeans and beans show the most acute need for this element.

The disruption of chlorophyll synthesis processes caused by zinc deficiency leads to the appearance of light green, yellow and even almost white chlorotic spots on the leaves.

Cobalt

So, cobalt is part of vitamin B 12, with a lack of which metabolic processes are disturbed, in particular, the synthesis of proteins, hemoglobin, etc. is weakened.

Insufficient provision of feed with cobalt at a content of less than 0.07 mg per 1 kg of dry weight leads to a significant decrease in the productivity of animals, and with a sharp lack of cobalt, livestock becomes ill with dryness.

iodine

As chemical analysis shows, plants also contain elements such as sodium, silicon, chlorine, and aluminum.

Sodium

Silicon

Chlorine

Citrus crops, tobacco, grapes, potatoes, buckwheat, lupins, seradella, flax, and currants are very sensitive to the high content of chlorine in the soil. Less sensitive to a large amount of chlorine in the soil are cereals and vegetables, beets, and herbs.

Aluminum

In addition to the mentioned macro - and microelements, plants contain a number of elements in negligible amounts (from 108 to 10 - 12%), called ultramicroelements. These include cesium, cadmium, selenium, silver, rubidium, and others. The role of these elements in plants has not been studied.
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Tatyana Rudakova

The main substances that make up the protoplasm of cells (it is in them that the most important biochemical and physiological processes for plant life occur) are proteins. Proteins are made up of carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, iron, and other elements. In extremely small quantities, microelements are present in plants: manganese, copper, zinc, molybdenum, boron, etc.

Plants obtain carbon from two sources: air carbon dioxide during photosynthesis and from organic matter in the soil.

Oxygen enters plants from the air during their respiration and, in part, from water from the soil.

Nitrogen, potassium, phosphorus, iron, sulfur and other plant elements are obtained from the soil, where they are in the form of mineral salts and are part of organic substances (amino acids, nucleic acids and vitamins). Through the root, plants absorb from the soil mainly ions of mineral salts, as well as some waste products of soil microorganisms and root secretions of other plants. The absorbed compounds of nitrogen, phosphorus and sulfur interact with the products of photosynthesis flowing from the leaves to form amino acids, nucleotides and other organic compounds. Through the vessels of the plant, elements in the form of ions (potassium, calcium, magnesium, phosphorus) or organic molecules (nitrogen, sulfur) move to the leaves and stems as a result of the action of root pressure and transpiration. Alkaloids (for example, nicotine), growth hormones (kinins, gibberellins) and other physiologically active substances are also synthesized in the root. The roots also secrete auxins and other substances that stimulate plant growth.

The bulk of the chemical elements that plants need for nutrition are found in the soil in insoluble compounds, therefore they are not available for absorption by plants. Only a small part of substances containing nutrients can be dissolved in water or weak acids and absorbed by plants. Insoluble nutrients take on a form available for assimilation under the influence of soil microorganisms. Microorganisms also secrete antibiotics, vitamins and other substances useful to plants.

Macronutrients are elements that plants need in significant quantities, their content in the plant reaches 0.1 - 5%. Macronutrients include nitrogen, potassium, phosphorus, sulfur, calcium, and magnesium.

Nitrogen(N) is part of the amino acids that make up protein molecules. It is also part of the chlorophyll involved in plant photosynthesis, and enzymes. Nitrogen nutrition affects the growth and development of plants, with a lack of it, plants poorly develop green mass, branch poorly, their leaves become smaller and quickly turn yellow, flowers do not open, dry out and fall off.

Nitric and nitrous acid salts, ammonium, urea (urea) can serve as a source of nitrogen for plant nutrition.

Potassium(K) in plants is in ionic form and is not part of the organic compounds of the cell. Potassium helps plants absorb carbon dioxide from the air, promotes the movement of carbohydrates in the plant; it is easier to endure drought, because it retains water in the plant. With insufficient potassium nutrition, the plant is more quickly affected by various diseases. Potassium deficiency causes a weakening of the activity of some enzymes, which leads to disturbances in the protein and water metabolism of the plant. Outwardly, the signs of potassium starvation are manifested in the fact that old leaves turn yellow prematurely, starting from the edges, then the edges of the leaves turn brown and die. The absorption of potassium by a plant directly depends on the growth of the root mass: the higher it is, the more potassium is absorbed by the plant.

Potash mineral fertilizers include potassium chloride and potassium sulfate.

Phosphorus(P) is part of the nucleoproteins, the main component of the cell nucleus. Phosphorus accelerates the development of crops, increases the yield of flower products, and allows plants to quickly adapt to low temperatures.

Phosphate mineral fertilizers include superphosphate, phosphate rock, salts of orthophosphoric acid. It is only necessary to take into account that in a neutral and alkaline medium, poorly soluble salts are formed, the phosphorus of which is not available to plants.

Sulfur(S) is part of proteins, enzymes, and other organic compounds of plant cells. With a lack of sulfur, young leaves evenly turn yellow, the veins become purple. Gradually lose their green color and older leaves.

Special sulfur fertilizers are usually not applied, because it is contained in superphosphate, potassium sulfate, and manure.

Calcium(Ca) is necessary for both aboveground organs and plant roots. Its role is associated with plant photosynthesis and the development of the root system (with a lack of calcium, the roots thicken, lateral roots and root hairs do not form). Calcium deficiency appears at the ends of the shoots. Young leaves lighten, light yellow spots appear on them. The edges of the leaves are bent down, taking the form of an umbrella. With a strong calcium deficiency, the top of the shoot dies.

Magnesium(Mg) is part of chlorophyll, activates an enzyme that converts carbon dioxide during photosynthesis. Participates in energy transfer reactions.

Signs of magnesium deficiency begin to appear from the lower leaves, then spread to the upper ones. With a lack of this element, chlorosis has a characteristic appearance: at the edges of the leaf and between its veins, the green color changes not only to yellow, but also to red and purple. The veins and adjacent areas remain green. In this case, the leaves often arch in a dome-like manner, since the tips and edges of the leaf are bent.

Magnesium fertilizer is a drug Kalimag.

There is a large number of fertilizers on the macro fertilizer market, which can be very difficult to understand and choose something suitable. Qualitatively, all fertilizers differ in the chemical composition of their components, that is, how quickly substances containing nutrients are quickly absorbed by plants. It is worth giving preference to those preparations that contain soluble salts: monopotassium phosphate, monoammonium phosphate, potassium sulfate, potassium nitrate.

Trace elements in the body of a plant are contained in a much smaller amount, from 0.0001 to 0.01%. These include: iron, manganese, copper, zinc, molybdenum, boron, nickel, silicon, cobalt, selenium, chlorine, etc. As a rule, these are metals of the transition group of the periodic system of elements.

Trace elements do not affect the osmotic pressure of the cell, do not participate in the formation of protoplasm, their role is mainly associated with the activity of enzymes. All key metabolic processes, such as the synthesis of proteins and carbohydrates, the breakdown and metabolism of organic substances, the fixation and assimilation of some key nutrients (for example, nitrogen and sulfur), occur with the participation of enzymes that ensure their flow at ordinary temperatures.

With the help of redox processes, enzymes have a regulatory effect on plant respiration, maintaining it at an optimal level under adverse conditions.

Under the action of microelements, plant resistance to fungal and bacterial diseases and such adverse environmental conditions as lack of moisture in the soil, low or high temperatures, and difficult wintering conditions increase.

It is assumed that the synthesis of plant enzymes itself proceeds with the participation of microelements.

Research in the field of determining the role of various trace elements in plant metabolism began in the middle of the 19th century. A detailed study began in the 30s of the 20th century. The function of some of the trace elements is still unclear and research in this area is ongoing.

Iron(Fe) is found in chloroplasts, is a necessary element of many enzymes. Participates in the most important biochemical processes: in photosynthesis and synthesis of chlorophyll, nitrogen and sulfur metabolism, cell respiration, its growth and division.

Iron deficiency in plants is often found when there is an excess of calcium in the soil, which happens on carbonate or acidic soils after liming. With a lack of iron, interveinal chlorosis of young leaves develops. With an increasing iron deficiency, the veins may also lighten, the leaf turns completely pale.

Manganese(Mn) dominates the metabolism of organic acids and nitrogen. It is part of the enzymes responsible for plant respiration, participates in the synthesis of other enzymes. Activates enzymes responsible for oxidation, reduction and hydrolysis. Directly affects the conversion of light in the chloroplast. Plays an important role in the mechanism of action of indoleacetic acid on cell growth. Participates in the synthesis of vitamin C.

Signs of manganese deficiency appear on young leaves. Chlorosis appears first at the base of the leaf, and not at its ends (which resembles a potassium deficiency). Then, with a growing lack of manganese, interveinal chlorosis appears and, after the death of chlorosis tissue, the leaf becomes covered with spots of various shapes and colors. Leaf turgor may be weakened.

Manganese deficiency intensifies at low temperatures and high soil moisture.

Copper(Cu) is involved in the metabolism of proteins and carbohydrates, activates some enzymes, is involved in photosynthesis, is important in nitrogen metabolism. Increases plant resistance to fungal and bacterial diseases, protects chlorophyll from decay. For the life of the plant, copper cannot be replaced by another element.

With a lack of copper, white spots appear on the tips of young leaves, they lose turgor, ovaries and flowers fall. The plant has a dwarf appearance.

Zinc(Zn) is involved in the formation of tryptophan, a precursor of auxin (growth hormone), and in protein synthesis. Essential for the conversion and consumption of starch and nitrogen. Increases the resistance of the plant to fungal diseases, with a sharp change in temperature increases the heat and frost resistance of the plant.

With a lack of zinc in plants, the synthesis of vitamins B1 and B6 is disrupted. Zinc deficiency manifests itself more often on older lower leaves, but with increasing deficiency, younger leaves also turn yellow. They become spotty, then the tissue of these areas falls through and dies. Young leaves may be small, their edges twist upward.

Zinc fertilizers increase drought, heat and cold resistance of plants.

Molybdenum(Mo) is part of the enzyme that converts nitrates to nitrites. Needed by the plant for nitrogen fixation. Under its influence, the content of carbohydrates, carotene and ascorbic acid increases in plants. The content of chlorophyll and the activity of photosynthesis increase.

With a lack of molybdenum, nitrogen metabolism is disturbed in the plant, mottling appears in old, and then in middle-aged leaves. Plots of such chlorotic tissue then swell, the edges twist upward. Necrosis develops on the tops of the leaves and along their edges.

Bor(B) is involved in the synthesis of RNA and DNA, in the formation of hormones. It is necessary for the normal functioning of the growth points of the plant, i.e., its youngest parts. It affects the synthesis of vitamins, flowering and fruiting, seed maturation. Enhances the outflow of photosynthesis products from leaves to bulbs and tubers. Necessary for the water supply of the plant. Boron is essential for plants throughout the growing season. For the life of the plant, boron cannot be replaced by another element.

With a lack of boron in plants, the growth point is affected, both the apical buds and young roots die, and the vascular system is destroyed. Young leaves turn pale, become curly. Lateral shoots develop intensively, but they are very brittle, the flowers fall off.

Chlorine(Cl) is an activator of enzymes that release oxygen from water during photosynthesis. Cell turgor regulator, contributes to drought resistance of plants.

Plants more often show signs of not a lack, but an excess of chlorine, expressed in premature drying of the leaves.

Some macro- and microelements can interact, which leads to a change in their availability for the plant. Here are some examples of such influence:

Zinc phosphorus, high levels of available phosphorus provoke zinc deficiency.

Zinc nitrogen, high nitrogen levels cause zinc deficiency.

Iron-phosphorus, an excess of phosphorus leads to the formation of insoluble iron phosphate, i.e. inaccessibility of iron to the plant.

Copper-phosphorus, an excess of phosphorus leads to the formation of insoluble copper phosphate, that is, the occurrence of copper deficiency.

Molybdenum-sulfur, the assimilation of molybdenum by plants decreases with an excess of sulfur.

Zinc magnesium, when using magnesium carbonate, an increase in soil pH and the formation of insoluble zinc compounds occur.

Iron-manganese, an excess of manganese prevents the movement of iron from the roots of the plant upwards, leading to glandular chlorosis.

Iron molybdenum, in low concentrations, molybdenum promotes the absorption of iron. At high concentrations, it interacts with it, forming insoluble iron molybdate, which leads to iron deficiency.

copper nitrogen, the introduction of large doses of nitrogen fertilizers increases the need for copper in plants and increases the symptoms of copper deficiency.

copper-iron, excess copper provokes iron deficiency, especially in citrus fruits.

copper-molybdenum, excess copper interferes with the absorption of molybdenum and increases the level of nitrates in the plant.

copper-zinc, an excess of zinc leads to a deficiency of copper. The mechanism of this effect has not yet been studied.

Boron-calcium, there is evidence that with a lack of boron, plants cannot normally use calcium, which can be in sufficient quantities in the soil.

Boron-potassium, the amount of absorption and accumulation of boron by plants increases with an increase in potassium in the soil.

Currently, work is underway to study the role in plant physiology of such elements as arsenic(As) mercury(Hg), fluorine(F) iodine(I) and others. These elements were found in plants in even smaller amounts. For example, in some antibiotics produced by plants.

The deficiency of elements is directly related to the property of the soil: on very acidic or alkaline soils, plants, as a rule, are deficient in trace elements. An excess of phosphates, nitrogen, calcium carbonate, iron and manganese oxides also leads to this.

The lack of microelements in the soil does not necessarily lead to the death of the plant, but it is the reason for the decrease in the speed and consistency of the processes responsible for the development of the organism.

Symptoms of deficiency of a particular element can be very characteristic and are most often manifested in chlorosis. Although objectively, to identify the deficiency of some element, an analysis of soils and plant tissues is required.

Diagnosis of insufficiency of individual elements in appearance, the plant presents difficulties for a non-specialist:

A change in the appearance of a plant, similar to a lack of elements, can be caused by damage by pests, diseases or adverse factors: temperature, flooding or overdrying of an earthen coma, as well as insufficient atmospheric humidity;

External signs of mineral starvation caused by a deficiency of a particular element may differ slightly in different plants (for example, symptoms of sulfur deficiency in grapes and legumes). And specifically for hoy, this issue has not been studied at all;

In the case of a deficiency of several nutrient elements, external signs overlap, the plant first of all compensates for the deficiency of the element that is lacking more. Signs of a lack of another element remain, outwardly the chlorosis of the plant continues;

To determine which element a plant lacks, dynamics in changing external signs is necessary, and it is different when different elements are lacking. Amateurs pay little attention to changes in the nature of manifestations, which makes diagnosis difficult;

Nutrients are present in the soil, but are not available to the plant due to its inappropriate acidity.

In order to determine by external signs which particular nutrient a plant lacks, you should first pay attention to which leaves, young or old, show deficiency symptoms.

If they appear on old leaves, a lack of nitrogen, phosphorus, potassium, zinc or magnesium can be assumed. These elements, when they are deficient in the plant, move from the old parts to the young, growing ones. And in them there are no signs of starvation, while chlorosis appears on the lower leaves.

If deficiency symptoms appear at growing points or on young leaves, we can assume a lack of calcium, boron, sulfur, iron, copper and manganese. Apparently, these elements are not able to move through the plant from one part to another. And if there are few of these elements in the soil, the growing parts do not receive them.

Therefore, amateurs in a situation where chlorosis begins in their plants, but they are sure that the plant is healthy and is in favorable conditions, should treat their plant with a whole complex of macro- or microelements. When choosing drugs, it should be understood that the effectiveness of the effect of a microelement on a plant directly depends on the form in which it resides. And the insufficient intake of microelements into the plant is often associated with their presence in the soil in an insoluble, inaccessible form for the plant.

About what types of microfertilizers the market offers.

First of all, there are many micronutrient fertilizers on the market, which are soluble mineral(inorganic) salts of these elements (magnesium sulfate, zinc sulfate, etc.). Their use is relatively inexpensive, but has a number of serious disadvantages:

These salts are soluble, that is, available to plants, only in soils with slightly acidic and acidic soil;

When using soluble salts of microelements, the soil is salted with various cations and anions (Na, Cl);

When mixing various metal salts, their interaction is possible with the formation of insoluble salts, that is, compounds inaccessible to plants.

Therefore, it is more promising to use sodium and potassium salts of humic acids. They are weak natural chelates and are highly soluble.

Humic preparations Humate+7, Humisol, GROUP Energy, Lignohumate, Viva and others contain 60-65% humates (in dry form) and seven basic trace elements (Fe, Cu, Zn, Mn, Mo, Co, B) in the form of complex compounds with humic acids. They may contain macronutrients and vitamins. These fertilizers are obtained by treating peat or brown coal with an alkali solution at high temperature and extracting the main product from it. In essence, these fertilizers are organic, they do not contain more trace elements than manure, and they cannot be considered a full-fledged micronutrient top dressing.

Deserving the most attention trace elements in chelated form (chelates). And before talking about the specific names of microfertilizers in this form, we should dwell on what chelates are. They are obtained by the interaction of metals (trace elements) with natural or synthetic organic acids of a certain structure (they are called complexones, chelants or chelating agents). The resulting stable compounds are called chelates (from the Greek "chele" - claw) or complexonates.

When interacting with a metal, an organic molecule, as it were, captures the metal in a “claw”, and the plant cell membrane recognizes this complex as a substance related to its biological structures, and then the metal ion is absorbed by the plant, and the complexon breaks down into simpler substances.

The main idea of ​​using chelators to improve the solubility of fertilizer salts is based on the fact that many metal chelates have a higher solubility (sometimes by an order of magnitude) than salts of inorganic acids. Considering also that in the chelate the metal is in a semi-organic form, which is characterized by high biological activity in the tissues of the plant organism, it is possible to obtain a fertilizer that is much better absorbed by the plant.

The acids most commonly used in the production of chelated microfertilizers can be divided into two groups. These are complexones containing in their composition carboxyl groups:

• EDTA (ethylenediaminetetraacetic acid), synonym: complexon-III, trilon-B, helaton III.
• DTPA (diethylenetriaminepentaacetic acid)
• DBTA (dihacid)
• EDDNMA (ethylenediamindi (2-hydroxy-4-methylphenyl) acetic acid)
• LPCA (Lignin Polycarboxylic Acid)
• NTA (nitrilotriacetic acid)
• EDDA (ethylenediaminesuccinic acid)

and complexones based on phosphonic acids:

• HEDP (hydroxyethylidene diphosphonic acid)
• NTP (nitrile trimethylene phosphonic acid)
• EDTP (ethylenediaminetetraphosphonic acid)

Of the complexones containing carboxyl groups, the most optimal is DTPA, it allows the use of complexonates (especially iron) on calcareous soils and at pH above 8, where other acids are ineffective.

In our market, as well as abroad (Holland, Finland, Israel, Germany), the vast majority of drugs are based on EDTA. This is primarily due to its availability and relatively low cost. Chelates based on it can be used on soils with a pH less than 8 (an iron-EDTA complex is effective in combating chlorosis only on moderately acidic soils; in an alkaline environment, it is unstable). In addition, chelates with EDTA are decomposed by soil microorganisms, which leads to the transition of trace elements to an insoluble form. These drugs exhibit antiviral activity.

Chelates based EDDNMA are highly effective, they can be used in the pH range from 3.5 to 11.0. However, the cost of this complexone, and hence microfertilizers, is high.

Of the complexones containing phosphonic groups, the most promising is OEDF. On its basis, all individual metal complexonates used in agriculture, as well as compositions of various compositions and ratios, can be obtained. In its structure, it is closest to natural compounds based on polyphosphates (during its decomposition, chemical compounds are formed that are easily absorbed by plants). Chelates based on it can be used on soils with a pH of 4.5-11. A distinctive feature of this complexone is that, unlike EDTA, it can form stable complexes with molybdenum and tungsten. However, HEDP is a very weak complexing agent for iron, copper, and zinc; in the root zone, they are replaced by calcium and precipitate. For the same reason, it is unacceptable to prepare working solutions of chelates based on HEDF in hard water (it must be acidified with a few drops of citric or acetic acid). HEDP is resistant to the action of soil microorganisms.

Chelating properties are currently being researched humic(humic and fulvic acids) as well as amino acids and short peptides.

It is impossible to give an unequivocal answer to the question of which complexone should be used to obtain biologically active microelements: the complexones themselves are practically inert for plants. The main role belongs to the metal cation, and the complexone plays the role of a vehicle that ensures the delivery of the cation and its stability in soil and nutrient solutions. But it is the complexones that ultimately determine the effectiveness of the fertilizer as a whole, that is, the degree of assimilation of microelements by plants. If we compare the assimilation of microelements by plants from inorganic salts and their chelate compounds, then compounds based on lignins (for example, Brexil from Valagro) are absorbed 4 times better, based on citrates - 6 times, and based on EDTA, HEDP, DTPA - 8 times better.

According to the Directive of the European Union EU 2003/2003 of October 13, 2003. (this is a document regulating the activities of all without exception European producers of mineral fertilizers), the following chelating agents are allowed for free trade in the EU countries: EDTA, DTPA, EDDHA, HEEDTA, EDDHMA, EDDCHA, EDDHSA. All other types of chelating agents are subject to mandatory registration with the relevant government agencies separately in each country.

According to the Directive, the stability constant of microelement chelates, expressed in %, must be at least 80. In the chemistry of complex compounds, the stability constant characterizes the strength of the complex compound and indicates what is the ratio of the chelated microelement and its free cation in the fertilizer. In advertising materials, the term “chelation percentage”, unknown to chemists, appeared.

Advertising information should be treated with caution. Do not base your knowledge of the product solely on advertising brochures - the fertilizer manufacturer is not responsible for the information described in the advertising. The main and most reliable information about a product is its LABEL. The fertilizer manufacturer is obliged to indicate on the label which chelating agent was used to form a chelate of a particular trace element.

A manufacturer, especially a domestic one, however, does not always indicate on the packaging the name of the complexone that he used to produce microfertilizer. But, strictly following the instructions, the fertilizer can be used as efficiently as possible: if it is indicated that leaf processing is preferable, you need to follow this, apparently these chelates are highly dependent on soil acidity or are destroyed by soil microflora. If watering the plants is also possible, then the chelates are resistant to the listed factors.

Ways to use microfertilizers may be different:

Presowing treatment of seeds (by pollination or moistening);

Foliar feeding during the growing season (the so-called foliar or leaf method);

Irrigation with working solutions of microfertilizers.

The most rational and cost-effective are the first two methods. In these cases, plants use 40-100% of all trace elements, but when they are introduced into the soil, plants absorb only a few percent, and in some cases even tenths of a percent of the microelement introduced into the soil.

According to the physical state of microfertilizers can be:

Liquid, these are solutions or suspensions with a metal content of 2-6%;

Solid, these are crystalline or powdery substances with a metal content of 6-15%.

According to the composition of microfertilizers there are:

1. NPK fertilizers + trace elements in chelated form, which contain various combinations of macronutrients N, P, K (also Mg, Ca, S are possible) and a fixed amount of microelements in the entire product range.

2. Preparations containing only trace elements, which in turn are also divided into:

• complex - containing a composition of trace elements in a certain proportion;
• monofertilizers (chelates of monoelements) - compounds of individual metals: iron, zinc, copper. As a rule, they are used when symptoms of diseases associated with a lack of a particular element appear.

3. Fertilizers containing, in addition to trace elements, biologically active substances: stimulants, enzymes, amino acids, etc.

From fertilizers NPK + trace elements There are several preparations of the company NNPP "Nest M" (Russia) on sale: Cytovit(N, P, K, Mg, S, Fe, Mn, B, Zn, Cu, Mn, Co) and Siliplant(Si, K, Fe, Mg, Cu, Zn, Mn, Mo, Co, B). It should be noted that this is the first domestic microfertilizer that contains silicon (potassium is present in the preparation for its more efficient absorption). It is available in several brands with different ratios of trace elements.

Buysky Chemical Plant (Russia) manufactures the drug Aquarin (№5, №13, №15).

The company VALAGRO (Italy) offers fertilizers Master(16 items, of which the most interesting are "18+18+18+3", "13+40+13", "15+5+30+2", "3+11+38+4"), Plantafol(in the same proportion of trace elements + NPK variations) and Brexil Mix.

I would like to note that these fertilizers should be considered rather as correctors of mineral nutrition, and not as a source of trace elements.

From preparations containing only trace elements, NNPP "Nest M" (Russia) offers Ferovit(content of chelate iron not less than 75 g/l, N-40 g/l).

Firm Reakom (Ukraine) offers microfertilizer Reakom-Mik(complexone is HEDF) with a different ratio of the main trace elements (Fe, Mn, Zn, Cu, Co, Mo) and B, designed for the needs of a wide variety of crops: tomatoes, cucumbers, grapes, flower crops.

The VALAGRO company also produces microfertilizers in the form of one-component formulas, such as Brexil Zn, Brexil Fe, Brexil Mg , Brexil Mn , Brexil Ca(chelates of these fertilizers are made on the basis of LPKK complexon).

To microfertilizers with the addition of biostimulants refers to the drug from the company Reakom (Ukraine) under the brand name Reastim, which is a complex of microfertilizers with known growth stimulants (hetero- and hyperauxins, succinic acid, gibberillin, humic acids, etc.).

Nanomix LLC (Ukraine) produces liquid microfertilizer Nanomix containing chelates of Fe, Mn, Zn, Cu, Co, Mg, Ca, Mo, (plus B and S) with the addition of natural biostimulants-adaptogens based on polycarboxylic acids. HEDP and EDDA were used as complexing agents (which allows the fertilizer to be used on acidic, neutral and slightly alkaline soils). The seed treatment preparation also includes a root system growth stimulator - heteroauxin.

Plant nutrition depends both on external factors (light, heat, soil composition) and on what phase of development the plant is in (in the phase of growth, flowering, dormancy). Therefore, when buying fertilizers, you should pay attention to the ratio of nutrients in it. So an increased nitrogen content is necessary for the plant in the spring, in the phase of active growth. In summer, for flowering and fruiting, the fertilizer must contain more phosphorus. In autumn, for the ripening of young shoots, the fertilizer should not have nitrogen at all, and potassium should be present in high concentrations. In winter, indoor plants are fertilized extremely rarely (and in low concentrations), because at rest the plant does not consume many nutrients. Their application can burn the roots or, under conditions of elevated temperature and short daylight hours, will provoke growth that will be weakened.