Table of contents:
- The main elements of plant soil nutrition
- Several important points in fertilizing with fertilizers
- Similar symptoms of eating disorders
Regular feeding of indoor plants with fertilizers should become a routine procedure for you, since many so-called plant diseases are caused precisely by improper care associated with a lack of nutrition.
The main elements of plant soil nutrition
Nutrients are found in the soil in the form of mineral and organic compounds. Plant nutrients are obtained from the soil in dissolved form through the root system. However, it is possible to provide plants with nutrients to a certain extent through the leaves (foliar feeding). We will tell you about the most important macro- and microelements, what is their deficiency and excess.
Signs of a nitrogen deficiency - severe yellowing of leaves
Nitrogen is a part of complex compounds from which protein is built - the basis of living matter. Nitrogen is also part of chlorophyll, which plays an important role in plant photosynthesis. Nitrogen is especially necessary for the leaves, with a lack of nitrogen, the leaves become pale green, then turn yellow, plant growth is delayed, the leaves become smaller.
From a lack of nitrogen, the lower leaves of plants first turn yellow, then gradually yellowing covers the entire plant.
Excess nitrogen - the leaves become dark green, large and juicy, flowering (and ripening of fruits in lemon, orange, etc.) is delayed. In succulent plants (such as cacti, aloe, etc.), excess nitrogen causes thinning of the skin, which bursts, causing the plant to die or leaving ugly scars. Nitrogen fertilizers (ammonium nitrate, ammonium sulfate) and organic fertilizers (manure or slurry) are used to feed plants with nitrogen.
Lack of phosphorus on the leaves
Phosphorus is part of the so-called nucleoproteins, the main constituent of the cell nucleus. Phosphorus provides energy processes in plant cells.
With a lack of phosphorus, the leaves become dark green, acquire a slightly bluish tint, brown or red-violet spots appear, which gradually cover the entire leaf. First of all, the old lower leaves are affected, then the process spreads to the whole plant. The growth of shoots and roots is greatly slowed down, new leaves are small, flowering is delayed.
With an excess of phosphorus, which is quite rare, the absorption of iron and zinc is impaired in the plant - mezhil chlorosis appears on the leaves. Phosphate mineral fertilizers include superphosphate, phosphate rock, etc.
Signs of potassium deficiency
Potassium is involved in nitrogen metabolism (helps the plant to absorb carbon dioxide from the air) and hydration of proteins in cells. Potassium is especially necessary for flowers, with a lack of potassium, flowers are not formed or they are very small.
With a lack of potassium, ammonia accumulates in the cells, from which tissue death begins (the leaves turn yellow from the edges and begin to gradually fall off). Plant growth is abruptly delayed. A characteristic sign of potassium starvation is a light border over the entire surface of the leaf. Moreover, yellowing begins from the top of the leaf and further down between the veins to the petiole. In addition, with a lack of potassium, plants are more easily exposed to fungal diseases.
With an excess of potassium, growth retardation can also be noted. At the same time, the leaves acquire a darker shade, and the new leaves become smaller. An excess of potassium leads to difficult assimilation of elements such as calcium, magnesium, zinc, boron, etc. Potassium mineral fertilizers include potassium chloride, potassium sulfate, 40% potassium salt, etc. If it is established that the plant has a lack of potassium, then best applied by watering or spraying with potassium humate.
Sulfur is one of the sources of building proteins in cells. Essential for normal plant growth and development.
With a lack of sulfur, the leaves become light, the growth and development of the plant stops. In general, the picture is very similar to the signs of nitrogen deficiency, with the only difference that the yellowing, which occurs gradually, begins with younger leaves. At the same time, yellowed leaves almost do not fall off.
With an excess of sulfur, the leaves gradually turn yellow from the edges and shrink, tucking inward. Then they turn brown and die. Sometimes the leaves take on a lilac-brown hue rather than yellow. Special sulfur fertilizers are not applied to the soil, since sulfur is contained both in manure and in superphosphate, which are introduced into the soil (in purchased soil mixtures).
This is how the lack of calcium appears on the leaves of Saintpaulias grown on too acidic soils.
Calcium is also very necessary for plants - it participates in carbohydrate and nitrogen metabolism, ensures the permeability of the cell walls.
Calcium deficiency weakens root growth, stem tops and young leaves die off. At the same time, young leaves (first of all) turn pale and curl, become as if corrugated, then die off. Lack of calcium leads to a decrease in the pH of the soil, while the plant ceases to absorb other nutrients. Against the background of a lack of calcium, signs of "general starvation" can be noted. An excess of elements such as nitrogen, potassium and magnesium leads to a lack of calcium. Calcium is especially necessary for cacti with large or multiple thorns.
An excess of calcium leads to impaired assimilation of the same elements, respectively - nitrogen, potassium, as well as boron and iron. That manifests itself as mezhilkovy chlorosis of leaves and the appearance of light shapeless spots of dying leaf tissues.
Magnesium is part of chlorophyll and participates in plant photosynthesis.
With a lack of magnesium, the leaves turn pale, chlorosis is possible, which manifests itself in the fact that yellowing between the longitudinal veins begins on the leaf blade, first these are small specks that increase in size, then wide stripes, the veins themselves remain green. Then the leaf becomes orange and reddish, turns brown and dies off. Flowering is delayed, plant growth slows down. Magnesium deficiency manifests itself primarily on the old lower leaves of plants.
With an excess of magnesium, the roots of the plant begin to die off, the plant ceases to absorb calcium, and symptoms occur that are characteristic of a lack of calcium. Magnesium is obtained from organic fertilizers. Magnesium deficiency primarily occurs on acidic soils.
Meshilkovy chlorosis with iron deficiency
Iron is involved in the formation of chlorophyll and proteins. Since the degree of solubility of iron assimilated by the roots of plants directly depends on the acidity of the soil, the amount of easily assimilable iron is greater on soils with an acidic pH reaction. Therefore, iron deficiency is more likely to form in alkaline soils.
With a lack of iron, the formation of chlorophyll stops, the leaves turn light yellow (chlorosis). This will not manifest itself as with a lack of magnesium, when yellowing occurs along the veins, and yellow spots are formed first between the veins, and then along the entire surface of the leaf. Chlorosis of the leaves begins with young leaves and then spreads to older leaves, encompassing the entire plant.
An excess of iron occurs quite rarely, while the growth of the root system and the entire plant stops. In this case, the leaves take on a darker shade. If, for some reason, the excess of iron turned out to be very strong, then the leaves begin to die off and crumble without any visible changes. With an excess of iron, the assimilation of phosphorus and manganese becomes difficult, therefore, signs of a lack of these elements may also appear.
Molybdenum is involved in nitrogen exchange.
The lack of molybdenum manifests itself primarily in acidic soils. Since with a lack of molybdenum, the content of chlorophyll in the tissues decreases, yellow spots appear on the leaves, between the veins or along the edge of the leaf. The edges of the leaves curl up and dry. Flowering plants produce flowers of ugly shapes.
An excess of molybdenum leads to a violation of the digestibility of copper, with, accordingly, signs of a lack of this element.
Deformation of leaves with a lack of boron
Boron is involved in the formation of the structure of cell walls and the synthesis of nucleic acids. Boron is necessary for plants for the normal functioning of growth points, i.e. the youngest parts of the plant.
Lack of boron leads to the accumulation of toxic substances (quinones) in plant tissues, causing plant poisoning. With a lack of boron, the apical buds die off and rot, and young plants die. The leaves turn brown, deform and die off. With a prolonged lack of boron, young leaves appear small, stems and leaves become thinner, flowers fall off or flowering does not occur at all.
Excess boron, on the other hand, starts from old lower leaves. At the same time, small brown spots appear on the leaves, gradually increasing and leading to the death of leaf tissues.
Manganese increases the assimilation of carbon dioxide in plants, i.e. plays an important role in photosynthesis and respiration of plants.
Manganese deficiency manifests itself primarily on soils with a high calcium content, these are usually old, alkalized soils, especially if hard water was used for irrigation. With a lack of manganese, the plants are slightly leafy. Signs of chlorosis can be seen on the leaves, while it will manifest itself not as with a lack of magnesium or iron, but in the form of small yellow dots and specks. Then the leaves turn pale, and pale yellow necrotic spots appear in place of the points. This is the so-called drip chlorosis. It usually starts from the edges of the leaf, covering the entire leaf blade.
An excess of manganese, in contrast to its deficiency, appears more often on acidic soils. As a result of an excess of manganese in plant cells, the content of chlorophyll decreases, so the symptoms will be the same as with a lack of magnesium, i.e. chlorosis begins to bleach, primarily from old leaves, brown necrotic spots appear. Leaves wrinkle and fly around.
Copper participates in the synthesis of proteins and carbohydrates, as well as in the processes of photosynthesis and respiration, increases the resistance of plants to fungal diseases.
Copper deficiency is observed with an excess of phosphorus, i.e. with excessive application of phosphorus fertilizers. Also, a lack of copper appears on humus-rich soils or excessive application of humus fertilizers, since copper ions are bound by humic substances. With a lack of copper, the turgor of the leaves is lost, they curl, and the plant withers. With a lack of copper, white chlorous spots appear on the leaves. The apical leaves, from which copper deficiency begins to appear, are too large and pale in color.
Excess copper is also extremely harmful to the plant. It manifests itself in the fact that the plant is inhibited in development, brown spots appear on the leaves, and they die off. The process begins with the lower older leaves.
Ways to use trace elements
- Seed treatment in solutions of microelements;
- Feeding plants through the soil and through the leaves during the growth and development of plants;
- Introduction of microelements into a mixture of organo-mineral fertilizers.
Signs of excess minerals
- Drooping leaves;
- White crust on the soil surface and the outer wall of the ceramic pot;
- Dry brown spots on the leaves, dry leaf edges;
- In summer, plant growth stops, and in winter, weak, elongated stems can be seen.
Several important points in fertilizing with fertilizers
- Lack or excess of micro- and macroelements causes certain changes in plant development. However, this may not appear immediately, but after a certain time of the latent (latent) period.
- An excess content of any element in the soil never compensates for the lack of other elements, but, on the contrary, can cause a negative reaction.
- An accurate diagnosis of a deficiency of a particular element is not always possible, primarily because a deficiency of some elements causes the same reaction. For example, a lack of iron, nitrogen and magnesium is manifested in the yellowing of the leaves (chlorosis). Also, the determination of nutritional disorders can be difficult by the species characteristics of plants or their physiological state. Often, a lesion with a flat mite causes the same picture that occurs when there is a lack of calcium in the soil (growth retardation, leaf twisting and leaf fall).
- Very often it turns out that in the soil there is a deficiency of some elements and an excess of others, or an excess of any element, it causes difficulty in assimilating another. So an excess of magnesium leads to a lack of absorption of calcium by the roots of the plant.
Similar symptoms of eating disorders
- The lack of nitrogen at the initial stage, when the old lower leaves begin to turn yellow, looks very similar to the signs of a lack of lighting in the autumn-winter time, which also manifests itself in the yellowing of the lower old leaves.
- Lack of nitrogen in some plants leads to the formation of an anthocyanin substance in the leaves, which causes the leaf to turn reddish. When affected by some types of mites, reddening of the leaves may also appear along with their deformation (twisting).
- Lack of potassium, manifested in wilting of leaves, when they brighten and dry from the edges, can be mistaken for a violation of watering and exposure to too dry air.
- The lack of copper, manifested in the loss of turgor by the tissues of plants, curling of leaves, is quite similar to the fact that the plant was dried out, not watered enough, and possibly kept at the same time in a bright, hot place.