This early summer has been cold and rainy. Sometimes there was a monthly precipitation rate per day. In such cases, all soluble nutrients are washed out of the soil layer to a great depth. It is necessary to help the plants and feed them. But who knows what?
Why are the recommended doses of fertilizers not always effective?
The reason for this is that our soils are very different in their chemical composition, and the content of vital nutrients in them is not the same. All nutrients are divided into macro and micronutrients.
Macro fertilizers are applied in large quantities. These are nitrogen, phosphorus and potash fertilizers.
The doses of micronutrient fertilizers are small, but their role in plant life is also great. They are part of vitamins, enzymes - living catalysts of reactions in organisms, both plants and animals.
The external signs of a lack of fertilizers in different plants are different, but there are general changes in growth and development caused by a lack or excess of nutrients. I want to draw their attention to external signs of a lack or excess of certain chemical elements in various cultures.
With a shortage nitrogen depressed growth, short and thin shoots, small inflorescences, weak leafiness of plants, weak branching, small leaves of a pale green color are observed. Moreover, the yellowing of the leaves begins with the veins and the adjacent part of the leaf blade, and the parts of the leaf that are far from the veins may still retain a light green color. The veins of the leaf with a lack of nitrogen are also light. Yellowing starts from the lower, older leaves. They can acquire yellowish-orange, purple (in cabbage) or bluish-purple (in tomato) shades. Leaves with a lack of nitrogen fall off prematurely, the maturation of plants is accelerated. In potatoes, the leaves are erect, in tomatoes, the stems become tough, thin, the fruits are small, brightly colored when ripe.
Signs of nitrogen deficiency should not be confused with leaf aging. Here, yellowing begins from the leaf blade, while the veins remain green. The reason for the yellowing of the leaves can also be a lack of moisture in the soil.
However, an excess of nitrogen causes an overly intense growth. The leaves of the plants are dark green. The harvested crop is poorly stored.
With a shortage phosphorus plants also exhibit inhibited growth, shoots are short, thin, leaves are small, prematurely falling off. The color of the leaves is dark green, bluish, dull. With a strong lack of phosphorus, a violet-red tint appears in the color of the leaves. When leaf tissues die off, dark, almost black spots appear. The characteristic signs of phosphorus deficiency are delayed flowering and maturation. Potatoes show weak lateral branching and weak tops. The bush is compressed. The leaves are dark green, wrinkled; during the tuberization period, a narrow, dark brown, almost black stripe appears at the tips of the lower leaves. The edges of the leaves dry up and wrap up. Budding is delayed by 3-5 days. Cabbage plants are dwarf, with dull dark green leaves with a strong purple tint. They fall off prematurely. In tomato, as a plant very sensitive to phosphorus deficiency, the signs of its deficiency appear very early. Cotyledons at seedlings are directed upward at an acute angle. Leaves and stems are bluish-green with purple and violet tints. Stems are thin, weak, tough. The fruits are set and ripen late.
Lack of phosphorus is more common in acidic soils with mobile forms of aluminum and iron.
Disadvantage potassium most often observed on peaty, floodplain, light-textured soils. More often, signs of its deficiency are noticeable in the middle of the growing season. The leaves acquire a bluish-green color with a bronze tint, become dull, the edges of the leaf turn yellow and dry out (marginal burn), the leaf blades wrinkle. The veins appear to be embedded in the leaf tissue. The stem is thin, loose, lodging. Growth, development of buds and inflorescences is delayed. The potato plant is undersized, the internodes are shortened in the upper part, the bush is spreading. Cabbage has weak growth, the leaves are dark green, with a bluish tinge, weakly chlorotic between the veins. The leaves are wavy, bent downward, and the burnt edges - upward. The growth of the heads of cabbage is delayed. The young leaves of tomatoes are wrinkled and curved. Fruits ripen unevenly and may have greenish or greenish-yellow spots against a red background. In a cucumber, the ovaries either dry up completely, or the fruits become ugly with a narrow end, while with a lack of nitrogen, they acquire a pear-shaped shape and quickly turn yellow.
Disadvantage calcium observed on sandy and acidic sandy loam soils, especially when applying large doses of potash fertilizers. Potassium, as a more mobile element, is absorbed by plants in the first place. Deficiency symptoms appear primarily on young leaves. They brighten, bend, their edges curl upward. The edges of the leaf are irregular in shape; brown scorching may be found on them. In plants, apical buds and roots are damaged and die off, the roots are strongly branched. In potatoes, the leaves in the upper part of the plants are small, curl upwards parallel to the main vein of the leaf, the formation of tubers is weak. Dark spots of dead tissue appear in the tubers. On cabbage, a marble spot and white stripes along the edges appear on the leaves. On older plants, the leaves are serrated. Their edges are curled. The growth point sometimes dies off.
Magnesium sandy and sandy loam soils are poor. With its lack, a characteristic form of chlorosis is observed - at the edges of the leaf and between the veins, the green color changes to yellow, red, violet. Tissues subsequently die off, while large veins and adjacent leaf areas remain green. The edges of the leaf are bent downwards, as a result of which the leaf is dome-shaped, the edges of the leaves wrinkle and gradually die off. The first signs of deficiency appear on the lower leaves. In potatoes, the lower leaves are pale green, brown spots appear between the veins. The tops dries up prematurely. On acidic soils, plants absorb manganese instead of magnesium. At the same time, a brown spot appears on the stems of potatoes, the leaves become brittle and fall off prematurely.
Disadvantage bora most often observed on swampy, as well as acidic soils after liming. Potatoes rarely suffer from boron deficiency. In some plants, it causes diseases: in beets - a "wormhole", in cabbage - a hollow stem. With a lack of boron in plants, the growth point dies off, apical buds and roots die off, the stems bend, lateral shoots develop vigorously, while the plants acquire a bush form. The leaves become pale green, scorched and curly. There is a lack of flowering or falling of flowers, fruits are not tied. In tomato, young leaves are dark purple (to black) in color. The fruits darken, areas of dead tissue appear.
With a shortage sulfur the stems are thin, the leaves are pale green, but the tissues do not die off. The first signs appear on young leaves.
Disadvantage gland found on acidic soils after liming. On the leaves of plants, uniform chlorosis (lightening) appears between the veins of the leaf. The upper leaves are pale green and yellow, with white spots between the veins (the entire leaf may turn white).
Disadvantage manganese most often occurs on peat bogs, floodplain soils. Chlorosis is observed between leaf veins in the form of yellowish-green or yellowish-gray spots between green veins. In the future, these spots die off, while spots of various shapes and colors appear. The first signs of manganese deficiency appear at the base of young leaves.
Disadvantage copper most often found on peaty-boggy soils. Potatoes are relatively resistant to deficiencies in this element. Onion leaves turn white and dry out.
Disadvantage zinc observed on acidic sandy and boggy soils. With its deficiency, the leaves turn yellow, a bronze tint appears. In plants, rosette is observed, internodes become short, leaves are small.
By the appearance of plants, one can also judge the harmful effects excess chlorine, manganese, aluminum. If they enter the plant excessively, leaf tissues die off, growth slows down, sometimes the plant dies.
Reacts strongly to excess chlorine potatoes. He has the first signs of the harmful effects of chlorine appear after flowering. The leaf slices are folded in a boat along the main vein, then a light brown rim appears on their edges. The leaves dry up but do not fall off. The stem is thin, short, the tops can die off in July. The harvest drops sharply. An excess of chlorine is observed when fertilizers containing a lot of chlorine are introduced into the soil.
With excessive moisture, a harmful effect is observed manganese... A brown spot appears in potatoes, leaf petioles and stems become watery, very brittle, chlorosis appears on the lower leaves, later leaf tissues die off and turn brown. The tops dries up prematurely, the yield is greatly reduced. At the first signs of manganese toxicity, the soil should be calcified. It is better to add dolomite containing magnesium.
According to external signs, one can judge the lack of one or another nutrient in the soil and the need of plants for feeding, which should be carried out without delay as soon as the plants show the first signs of deficiency, and it is better not to allow the appearance of these SOS signals at all. However, growth retardation and changes in the appearance of plants are not always due to a lack of these nutrients in the soil. Similar signs are sometimes caused by damage to plants by pests or diseases, as well as unfavorable growing conditions (drought, low temperature, etc.). It is important to be able to distinguish between these changes and signs of nutritional deficiencies.
Today trade organizations offer many different fertilizers to hobby gardeners. Do not rush to get the first one that comes across. It is good to use complex fertilizers, especially with the addition of trace elements. For each crop in different phases of development, a specific composition of fertilizers is produced. And what is suitable for potatoes in the second half of summer is not suitable for feeding young cucumber plants in greenhouses. In addition, different soils also lead to a different composition of top dressing for the same crop.
Wet top dressing is usually done. The prescribed amount of fertilizer is diluted in a bucket (or liter) of water and watered with this solution over an area of 1 m², and then a bucket of clean water is poured onto the plants so that there are no burns. If your plants are very lagging behind in development, it makes sense to do foliar feeding. The concentration of the solution should not exceed 1% in this case. The nutrients through the stomata will be absorbed by the leaves and used immediately. Dry dressing before rain or watering should be done carefully. For this, you can adapt a tight, small plastic bag. Carefully cut off a small corner of the bag with scissors. Pour fertilizer into the bag, after thoroughly mixing and crushing all the lumps. We carry this bag between the rows of carrots, parsley, onions and other crops, almost touching the ground. Fertilizers through the cut-out hole will evenly spill out onto the soil surface and there will be no danger of getting them onto the plants even if the rows are close.
candidate of agricultural sciences
Excess potassium delays the supply of nitrogen and magnesium to the cucumber. Growth is slowing down significantly. The internodes lengthen and the leaves turn white. At a later stage, mosaic spots appear on the leaves of the cucumber culture. The leaves begin to wither and fall off. The damage is local in nature, and the tissue undergoes a necrotic process.
Lack of potassium in cucumbers
Lack of potassium in the soil leads to the formation of a light edging on the leaves of the plant. Cucumber leaves darken and take on a domed shape.
cucumbers are rounded, noticeably tapering at the stalk. There is a rapid withering of the shoots.
Lack of potassium in cucumbers
Water with an ash solution - 1 tbsp. ash per 10 liters of water. Watering at the rate: one liter of the mixture per plant. Spray the leaves with a 0.5% solution of potassium permanganate and soap.
Fertilizing vegetable crops is required during the entire period of plant growth. Top dressing directly affects the yield of plants. Without top dressing, you can get a crop only by plowing virgin soil, and even then one year. Crop plants need balanced nutrients.
Fertilizing vegetables contributes to the development of powerful, healthy plants and an increase in yield, eliminates the deficiency of micro and macro nutrients in the soil. Top dressing has the greatest effect on crops of the family Solanaceae, pumpkin, as well as cabbage and green vegetables.
It should be remembered that top dressing does not replace the main fertilization, but only supplements it. You can feed the plants with dry or liquid (dissolved in water) fertilizers. For liquid and dry feeding, fast-acting organic fertilizers are used: bird droppings, mullein, slurry, as well as mineral fertilizers and ash.
Crops with a short growing season are usually fed once, and long crops are fed once during the growing season. The first feeding is done 15-20 days after planting the seedlings or days after sowing, the second - during the period of intensive plant growth and at the beginning of fruit formation. It is advisable to fertilize after rain or watering. As a rule, fertilizing with mineral fertilizers is stopped days before the start of harvesting.
Liquid fertilizers are very quickly absorbed by plants. They are introduced into the aisles, into shallow furrows, retreating from the plants to or into small holes made around the plants. For the first liquid feeding, an infusion of mullein (1:10), bird droppings (1:15) or slurry is usually used. The composition of subsequent dressings depends on the condition of the plants, which can be judged by their appearance.
For example, poor development and pale green leaves indicate a lack of nitrogen nutrition. At the same time, in some crops (cabbage, beets, etc.), the leaves acquire orange and red shades. They are small, short, thin shoots and grow at an acute angle to the main stem. With an excess of nitrogen, plants grow violently.
The leaves are dark green, large, thick. This is most often the case on organic-rich soils. Such soils should not be deeply and often loosened, as this leads to a sharp increase in microbiological processes and, due to the decomposition of organic matter, the content of nitrates increases greatly.
Nitrogen fertilizers are best applied immediately before sowing (in spring), when feeding with dry fertilizers in the aisles or liquid fertilizers in the furrows and holes. Foliar top dressing with nitrogen fertilizers is undesirable, since a lot of nitrogen is lost due to the fact that ammonia escapes into the air.
The lack of such a trace element as iron, we could more than once observed in our garden, this yellowing or paleness of the upper leaves, and this is called chlorosis... Plants that need an acidic reaction of the soil, such as hydrangea, blueberries, rhododendrons, azaleas, and everyone's favorite petunias, are especially susceptible to chlorosis. But other plants can be iron deficient as well.
Most often chlorosis occurs on calcareous soils... Iron, even if it is abundant in calcareous soil, cannot be absorbed by plants, because it is in a form inaccessible to them. Chlorosis can also be caused by a lack of nutrition, too dry or too wet soil, frost, various viral diseases, an excess of trace elements such as copper, zinc, manganese.
When chlorosis is just beginning to develop, the leaves of plants acquire a yellowish tint, and the network of veins is still green. With severe chlorosis, the leaves brighten even more, become almost white, the veins of the leaf also brighten (not to be confused with variegated forms of plants, in which the leaves must by definition be yellow or white). The edges of the leaves begin to die off, the tips turn brown.
Chlorosis begins to manifest itself first on young, and then on old leaves. Sometimes, with a lack of iron, young shoots or tree tops dry up. Sometimes chlorosis can be confused with other plant diseases, for example, tomato ring spot virus.
Since chlorosis most often occurs on alkaline (calcareous) soils, it is necessary to apply fertilizers to the soil that acidify the soil, and thus iron becomes available and absorbed from the soil by plants: ammonia nitrogen - ammonium salts, nitrate nitrogen - potassium, calcium or sodium nitrate... The soil can be acidified with a weak solution of sulfuric acid (no more than 10 ml per 10 liters of water) or added to the soil colloidal sulfur... Do not forget to prepare such solutions only in plastic buckets.
To fix the situation, you can also use iron chelate... Such a chelated solution can be prepared even at home, for this you need boiled water, citric acid, iron vitriol.
Pour cooled boiled water into a three-liter jar. Dissolve about 12 grams of citric acid in this water and stir well until the acid crystals are completely dissolved, then add about 8 grams of ferrous sulfate to this solution. The result is a light orange "rusty" liquid that can be used to feed plants.
When gardeners notice alarming symptoms such as leaf spots, wilting, or impaired growth, they believe it is caused by disease or pests, but there is another reason. Often, the improper development of plants is associated with the introduction of mineral substances in excess or, on the contrary, with a lack of them, what fertilizers a plant needs to correct such errors, you will learn from this article.
Deficiency of macro- and microelements occurs even with proper feeding of plants. The reasons for nutritional deficiencies can be weather (heavy rains provoke leaching of some substances into deeper layers of the soil) undesirable soil pH (for example, excessive acidity reduces the bioavailability of calcium and magnesium) damage to the root system by pests or by loosening the soil.
Lack of nutrition can be the result of improper administration of one of the substances, for example, an excessive amount of potassium complicates the availability of magnesium for plants. Luckily, the deficit or excess of fertilizer for plants can be corrected.
The role of fertilizers in plant life is known to everyone, it is not only health for horticultural crops, but also a good harvest for the gardener. Unfortunately, fertilizers do not always give a positive result. How to use fertilizers correctly? Check out common mistakes:
The effect of fertilizers on plant growth is quite high, especially nitrogen. With a nitrogen deficiency, plants grow slowly, and the leaves turn yellow, some parts of the plants turn pink. Nitrogen fertilizers will replenish the deficit, depending on the need for acidification of the soil, ammonium sulfate (recommended for rhododendrons, azaleas, conifers and blueberries) or ammonium nitrate is used, liquid fertilizer from nettle is also suitable for this purpose, in addition to nitrogen, nettle will provide plants with potassium.
An excess of nitrogen, especially in combination with a lack of phosphorus, potassium and watering, is very dangerous, plants grow actively to the detriment of flowering and fruiting, in autumn the plants weaken and become not resistant to frost, taking into account all this, we note that nitrogen fertilization is carried out only until July. The fight against excess nitrogen consists in good watering (water flushes nitrogen out of the soil) and the introduction of phosphorus and potassium fertilizers.
The demand for this component in plants increases during flowering and fruiting, phosphorus is also necessary for the development of the root system. If there is a deficiency of phosphorus, plant growth slows down, leaves become stiff and purple, plants bloom less.
Superphosphate will help eliminate the deficiency, but the absorption of phosphorus by plants is reduced on acidic soils and when applied simultaneously with nitrogen fertilizers. The availability of phosphorus is badly affected by temperatures below 13 ° C and the pH level below 6-7 in these cases, it is absorbed only by 40%.
An excess of phosphorus is almost impossible; more often gardeners complain of obvious signs of a lack of it.
With a deficiency of potassium, the growth of the root system and shoots is suppressed, chlorosis of the leaves is observed, the edges of old leaves turn yellow at the edges, in advanced cases the plants wither, vegetable plants are deformed and lose their taste. Potassium in soil is easy to supplement with potassium sulfate.
Excess potassium interferes with the absorption of magnesium, impairs the storage of fruits and frost resistance of plants. Feeding plants with ammonium sulfate will help solve the problem of excess potassium.
Calcium deficiency is manifested by wilting of buds and tops of plants, deformation of young leaves, dry rot and curly leaves appear on tomatoes, apple fruits are affected by dark spots. According to the erroneous opinion, the lack of calcium is replenished with fertilizers for liming the soil, in fact, such fertilizers contain poorly soluble calcium compounds, as a rule, it is calcium oxide or carbonate. The role of these fertilizers is limited only by reducing the acidity of the soil, while calcium nitrate is used to eliminate the calcium deficiency.
An excess of calcium is often observed when watering with hard water, which leads to chlorosis, a lack of boron, magnesium, potassium and phosphorus, which requires their additional introduction.
Magnesium deficiency is characterized by wilting and chlorosis of the leaves, primarily conifers and shrubs suffer. Sometimes, due to a lack of magnesium, the flowering of plants is delayed, necrosis, early leaf fall is possible. Solves the problem of magnesium sulfate deficiency. An excess of potassium is indicated by signs of calcium deficiency, since potassium makes it difficult for calcium to access the roots.
Iron deficiency is very similar to magnesium deficiency in its characteristics, the difference is that chlorosis appears only on young leaves. A decrease in the amount of iron in the soil is observed after liming, at high soil pH values and a weak supply of oxygen in the root zone.
Iron chelate is recommended as a source of iron for garden plants. An excess of iron is unlikely, symptoms - chlorosis, turning into necrosis, slow growth of shoots and roots.
With a lack of these microelements, chlorosis of the leaves is observed, the beets can die, and the sunflower does not give seeds. Boron prevents excess calcium, improves the supply of nitrogen, phosphorus, potassium and magnesium to the roots. Will increase the boron content - boric acid.
Molybdenum is involved in the transformation of nitrogen, is highly demanded by legumes, tomatoes, cabbage and lettuce.
Manganese is an activator of almost all processes in plant life and is urgently needed during the growing season. Manganese deficiency interferes with the normal growth and development of plants, leads to the occurrence of many diseases, the first signs of deficiency are chlorosis, and then leaf necrosis. Will fill the deficiency of manganese sulfate.
Everything is good in moderation. An excess of nutrients provokes a disturbance in the processes of vegetation, leads to the formation of nitrates and the death of tissues. Overdose is not beneficial, it is harmful. We will talk about mineral fertilizers, since the concentration in them, compared to organic matter, is quite high and mistakes occur more often.
It is important to understand that non-compliance with the norms, proportions and timing of application, especially nitrogen substances, is dangerous. Therefore, you need to carefully and competently use mineral supplements, do not use them "by eye", do not be guided by guesses and good intentions. As agronomists say: "the lack of knowledge cannot be compensated for by an excess of fertilizers."
Failure to comply with the norms and intervals reduces the quality, leads to losses in yield and even to the death of plants. Often, a gardener, noticing a deterioration in the condition of the seedlings, decides to make another feed. As a result, the soil is oversaturated and the crop dies. Unreasonably high doses of nitrogen - accumulation of nitrates. An interesting fact - the same harmful process occurs in fertile soil with a deficiency of phosphorus, potassium, molybdenum.
Why does the plant absorb nutrients? Let's consider the principle of operation. All fertilizers are transformed into inorganic salts in the soil, supplied as an aqueous solution. The basis of nutritional dynamics is the balance of salts. If the sap of the plant is saltier than the soil, then the soil solution is absorbed by the root system. The same concentration leads to a stop in the absorption of moisture from the soil. If the soil is more salty than the sap of the plant, then the worst thing happens - the outflow of liquid from the stem and the death of the culture.
An overabundance of each substance has its own symptoms, so you need to know the signs and be able to diagnose. Consider all oversaturation options.
Excess nitrogen is determined visually. The plant looks overfed, has an overly powerful stem, dark green tops. The growing season is lengthened, the flowering time is delayed, the harvest time is postponed, the quality of the fruits deteriorates. The susceptibility to fungal infections increases.
In tomatoes, chlorosis appears along the edges of the foliage with brown necrosis passing between the veins. The petioles are bent and the leaves are curled up. In cucumbers, old leaves are deformed, covered with transparent spots, which then turn yellow or become gray-brown. Fruits accumulate nitrates and grow smaller than usual.
In the production of vegetables, an overdose of phosphorus leads to the appearance of necrotic spotting, general yellowing, and leaf fall. Rapid aging occurs, and sensitivity to water shortages increases. In tomatoes, the ends of old leaves take on a brown or yellow tint, although the tissue remains intact, even with necrotic spots.
Signs of excess potassium are elongated internodes, growth retardation, light leaves. There is a delay in the absorption of nitrogenous compounds. The later stage is characterized by tissue necrosis, mosaic spots, wilting and foliage shedding.
If an excess amount of magnesium is added to the soil, then the leaves react by curling, becoming saturated dark. In tomatoes, the tops decrease in size, the ends of the leaves elongate and die off.
Calcium poisoning stimulates the increased growth of shoots, which quickly fade. On the leaves, interveinal chlorosis appears with a pale spot in the form of circles, sometimes filled with liquid.
If you make a mistake and exceed the fertilization rate, this will affect the condition of your pets. Observing the plants, you will determine the excessive presence of any element by external signs.
Prompt assistance will help to correct the situation. Watering is necessary, and it is recommended to spill the soil with a large amount of water (12-15 liters per square meter) once. This technique helps to wash out the active substances from the upper layer and transform them into deeper layers, 20-30 cm is enough. If the plants are compact, experts advise shedding several times with simultaneous transplantation and introduction of another soil into the hole. In any case, soil leaching gives results and the condition of the crops improves.
An excess of nutrients is no less harmful than a deficiency. Overnutrition can also be identified by the appearance of plants.
Nitrogen. With its excess in the plant, there is a delay in flowering and ripening. Outwardly, the overfed plant is distinguished by its dark green tops, excessively thick stems. The growing season is lengthened. Due to the accumulation of organic forms of nitrogen compounds, especially proteins, tissues become juicy and soft, more susceptible to fungal diseases and insect damage. The quality of the products of many crops deteriorates. In case of severe poisoning, the plants die within a few days.
Phosphorus. Excess phosphorus in vegetable plants leads to general yellowing, bright necrotic spots appear on them, leaves fall off. There is a very accelerated development of plants, they age quickly. High doses of phosphorus increase the sensitivity of plants to water shortages. In some plants, symptoms of excess phosphorus are similar to signs of potassium starvation, in others - to signs of excess nitrogen.
Potassium. With an excess of potassium, the flow of nitrogen into the plant is delayed. The accumulation of potassium leads to stunted plant growth. The internodes are lengthened, the leaves brighten. In later phases, mosaic spots appear on the leaves. Leaves wither and fall. Local damage, necrotic tissue.
Calcium. Excess calcium causes interveinal tissue chlorosis. The spots are pale, necrotic, sometimes concentric circles filled with water appear in them. On some plants, increased leaf growth begins, but the shoots die off. Signs of toxicity may mimic those of magnesium or iron deficiency.
Magnesium. With an excess of magnesium, the leaves become darker, sometimes abnormal curling of young leaves is observed.In tomato, the leaves are slightly reduced in size, at the later stages of growth, their ends are elongated and die off, especially in clear weather.
Sulfur. With an excess of sulfur, the leaves gradually turn yellow from the edges and shrink, tucking inward. Then they turn brown and die off. Sometimes the leaves do not take on a yellow, but a lilac-brown hue.
Iron. The symptoms of an excess of iron are the same as with a deficiency: chlorosis develops between the veins, later the leaves turn yellow and turn pale. Diseased plants either do not yield at all, or give a very low yield.
Molybdenum. An excess of molybdenum, like its deficiency, affects plants negatively - the leaves lose their green color, growth is delayed and the yield of plants decreases. An excess of molybdenum leads to a violation of the digestibility of copper, with corresponding signs of a lack of this element.
Copper. Excess copper leads to chlorosis of the lower leaves, which is accompanied by the formation of brown spots and leaf fall. Interveinal chlorosis of young leaves is also noted.
Manganese young leaves turn pale and yellow, necrotic dark-brown or almost white spots appear on them. The leaf blades are bent and wrinkled. On old leaves, interveinal necrosis develops, as a result of which they crumble. The lesion spreads along the plant from the bottom up. In case of severe poisoning, the plants stop growing, the leaves and petioles are covered with a mass of dark red dots.
Bor. High doses of boron cause toxicosis in plants, growth retardation, while boron primarily accumulates in leaf blades. An excess of boron causes a kind of burn of the lower leaves, marginal necrosis appears, the leaves turn yellow, die off and fall off. They can also curl up or down and acquire a domed shape. Together with the damaged leaves, the tops of the plants curl up. The yield decreases. The defeat is first observed on the leaves of the lower, and then the middle tier.
Different crops react differently to increased boron content in the soil. Boron content in mobile form over 30 mg / kg is the cause of severe plant diseases.
Boron toxicity threshold is determined not only by its content, but also by the amount and ratio of other nutrients. A good supply of plants with calcium and phosphorus increases their requirements for the supply of this element.
Zinc On the leaves at the base of the main veins, which remain green, transparent areas appear, causing necrosis. The veins of old leaves turn red or black, the leaves themselves fall off without withering. The upper kidneys die off. Interveinal necrosis develops, the underside of young leaves becomes purple, and old ones acquire a purple color, starting from the edges to the center. The leaves themselves are strongly curved downward.
Symptoms of early stage zinc poisoning are similar to those of iron deficiency.
Chlorine. Leaves coarse, become tough, small. The stem hardens. On old leaves of some plants, purple-brown spots appear, then the leaves fall off.
As a rule, these signs appear together with signs of nitrogen deficiency. In this case, fertilizing with ammonium nitrate (10-12 g per sq. M), followed by watering, helps. The harmful effect of chlorine is weakened by the addition of magnesium (kainit).
There are no special remedies against excess nutrients. They can be prevented by strict adherence to agricultural techniques.
Some macro- and microelements can interact, which leads to a change in their availability for the plant. Some examples of this influence include:
Zinc Phosphorus, high levels of available phosphorus provoke zinc deficiency.
Zinc-nitrogen, high nitrogen levels provoke zinc deficiency.
Iron-phosphorus, excess phosphorus leads to the formation of insoluble iron phosphate, i.e. the inaccessibility of iron for the plant.
Copper-phosphorus, excess 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, the pH of the soil increases and insoluble zinc compounds are formed.
Iron-manganese, an excess of manganese prevents the movement of iron from the roots of the plant upward, 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, excess zinc leads to copper deficiency. The mechanism of this influence 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 size of absorption and accumulation of boron by plants increase with an increase in potassium in the soil.
Novice gardeners often neglect the rules of feeding, which is why they do not get the desired result:
Proper feeding allows you to grow strong and healthy eggplants, bearing large fruits. In order not to harm the plants, it is necessary to adhere to the specified terms and rules, and use fertilizers in accordance with the instructions.
In plants from the aquarium, additional minerals are often used. feeding this calculation is carried out only for substances by weight, and real control of concentration in water is only available for some elements (nitrogen, iron, phosphorus ...). There are no tests available for most micronutrients. Under these conditions, it is very easy to get an excess of nutrients in the aquarium. The external manifestations of excessive nutrition in some cases are similar to when, the lack of this, the aquarist increases the dose of fertilizer even more, than worsens the situation.
as, Excess and lack of nutrients, leads to biochemical disruption of processes, which is expressed in slowing down the death, tissue growth or death of the plant.
There is not a lot of information about aquatic plants in the aquarium literature on nutrition, and it is generally difficult to find anything about the excess. Agrochemistry has gone a little further, but all the characteristics listed above relate to terrestrial plants, their aquatic environment can only be partially transferred to them. Nevertheless, the signs of the elements of excess nutrition with my comments will be listed below, and which of these signs concerns aquatic plants, and what you can, you will not find out for yourself by observing the plants and choosing the dose of fertilizers.
Nitrogen. When it is grown in excess, flowering and ripening are delayed. overfed Outwardly, the plant is distinguished by an excessively dark green, tops of thick stems. The vegetative accumulation is lengthened. Due to the period of organic forms of nitrogen compounds, especially proteins, the tissues become juicy and soft. In some plants, the signs of an excess of nitrogen are in many ways similar to a deficiency of potassium. Chlorosis develops first along the edges of the leaves, then between the veins and is accompanied by brown necrosis, while the ends of the edges are curled along the leaves, the petioles also bend. Described when, cases of severe poisoning of the plant for several days died.
With a lack, consequently, of carbohydrates, organic keto acids, the excess supply of ammoniacal nitrogen to plants can have a negative effect on this. In case of action, ammonia nitrogen does not have time to synthesize amino acids and accumulates in tissues, causing "ammonia poisoning" of plants. (Agrochemistry. Smirnov PM, Muravin EA). Ammonia poisoning also occurs faster with potassium deficiency.
In aquarium plants, ammonia poisoning can occur with an overdose of ammonium nitrate. For plants that have received such feeding, they begin to rot, the stem stops growing. After a few days, necrosis spreads to the main veins, while the leaves themselves may look quite finite. In healthy stages, the leaves fall off or die directly on the stem. With this kind of poisoning, the plant usually dies.
Phosphorus. An excess of plants in phosphorus leads to a general yellowing, necrotic spots appear on them, the leaves fall off. There is an accelerated development of plants, they age quickly (plants for seasonal growth). In some plants of excess, the symptoms of phosphorus are similar to those of potassium in others, in starvation they are similar to those of excess nitrogen.
Since many, as salts of phosphoric acid are difficult to dissolve, excess phosphates can lead to the fact that some trace elements will precipitate in the form of salts that are poorly soluble and their availability for plants will become them, signs of a deficiency of these elements may appear below. These elements include manganese, magnesium, iron, copper, zinc, cobalt, and other salts. The solubility of these elements is highly dependent on pH, as a rule, in an acidic environment, it is significantly potassium.
above. With an excess of potassium, nitrogen entry into the plant is delayed. The accumulation of potassium leads to growth retardation of plants. The internodes are lengthened, the leaves are more. In the later phases brighten, mosaic spots appear on the leaves. Leaves wither and fall. Damage to tissue, local necrotic. A decrease in the assimilation of nitrogen in excess with potassium can be associated with the fact that the ions of potassium and ammonium are assimilated one at a time through the same ion channels. Thus, an excess of potassium reduces the supply of ammonium by a competitive mechanism.
Magnesium. With an excess of magnesium, the leaves become darker, sometimes abnormal curling of young leaves is observed. In some cases, the leaves may decrease in size.
Calcium. Excess calcium causes interveinal tissue chlorosis. The spots are necrotic, pale, sometimes concentric of some appear in them. In the circles of plants, shoots begin to grow, but the leaves die off. Symptoms of toxicity may be similar to those of magnesium deficiency or Row.
iron of trace elements is characterized by a very narrow interval between deficiency and toxicity.
Iron. Symptoms of iron excess are the same as with deficiency: chlorosis develops between the veins, later the leaves turn pale and turn yellow (data for terrestrial plants).
Excess. Manganese manganese appears as interveinal young chlorosis of the leaves, which turn pale and yellow. dark Brown or almost white necrotic spots appear. Small red-brown dots may appear on the affected leaves. In contrast to the lack of manganese in its excess, the leaves are bent and boron.
shrivel. Leaves turn yellow and deformed, can curl down and take on a domed shape. Analysis of the boron content in the plant shows that it accumulates in a significant amount in old plant tissues; therefore, old leaves are affected first. The top of the plants first has a normal appearance, then rolls together with damaged leaves. Signs of damage to young and tops of leaves in advanced cases of toxic boron action can be mistaken for this element deficiency.
Copper. An excess of copper leads to chlorosis of the lower leaves, which is accompanied by the formation of brown spots and leaf fall. interveinal and Chlorosis of young leaves is noted.
Zinc. In some plants, an excess of zinc leads to the appearance of transparent areas at the base of the main veins, while the leaves remain green. Then chlorosis develops between veins. The upper buds die off, the old leaves fall off without withering, the veins on them are red in colored or black. The early stage of poisoning is similar to the signs of iron deficiency.
excess The influence of copper and zinc was studied in the dissertation of the Department of OA, Abdullina Plant Physiology, BSU. A number of experiments were carried out on hydroponics, the principles of such mineral fertilizing with a method closer to the conditions of the aquarium. The experiment was carried out at a 1.5-fold excess of the approximate concentration of the permissible Zn (1, 2 × 10-3 M) and the maximum allowable concentration of Cu (7, at -3 M), and 08 × 10 3-fold excess of the OEC of Zn and Cu (2, 4 × 10-3 M and 1, respectively, 3 M, 5 × 10). It is shown in the work that the growth of most plants slows down sharply with an excess of these elements. Acceleration of growth was noted only in plants especially resistant to excess copper and zinc. In all cases, an increase in the content of malonic MDA (dialdehyde) was noted, which indicates the defeat of the membrane result in lipids of their peroxidation by active forms of quality. In the oxygen protective mechanism in plants, peroxidase activation took place. Analysis of the metal content showed that a significant part of the zinc was accumulated in the shoots, and in the roots in copper.
Chlorine. With an excess of chlorine, the leaves coarsen, become tough, small. The stem is old. On the leaves of some plants, brown-purple spots appear, then the leaves fall off. Typically, these symptoms are manifested together with a lack of nitrogen symptoms. The harmful effect of chlorine with and is weakened by the introduction of magnesium.
Sodium. Most aquatic plants can grow over a wide range of this ion concentration. In fresh natural waters, there is not usually a toxic concentration of sodium. In the aquarium, you can get an excess amount as a result of the use of ion-exchange resins (sodium cation exchangers) to reduce the total hardness, as well as when using Na-containing drugs for treating fish or correcting the composition of chemical water (baking soda, sodium chloride, etc.). salt takes part in maintaining the osmotic state of cells, participates in the work of Na + -K + and H + channels, and can also replace potassium in some activation reactions. Sometimes. enzymes up to 2/3 of the potassium required for plants can be replaced with sodium without visible disturbances. this degree of substitution is different and depends on the type. High. Plants with sodium ion concentration can disrupt the chloroplast structure and have a harmful effect on metabolic processes. The positive effect of sodium on plants is manifested with a lack of potassium, but if there is enough potassium in the medium, the excess of sodium can be toxic (V.V. Polevoy, Physiology of plants). The characteristic excess signs of sodium ions for aquarium plants are not described.
Signs of excess in one element are often really similar to lack of another. In some cases, this is due to the fact that some are antagonistic elements. Being in solution and having the same charge in sign, they mutually suppress the action inherent in each of them. Among such antagonistic pairs are sodium and iron, potassium and manganese, calcium and magnesium ions. Also, antagonism was revealed not only for metal ions between themselves, but also with a proton.So, in an acidic environment, the pH is lower when 6, the absorption of cations (Ca2 +, Mg2 +, K +, etc.) is antagonistic due to the hindered action of hydrogen ions. Some acidic elements (Fe, Al) in the elements of the environment, on the contrary, are excessive if, and the availability of them in the soil is too much, they may have a toxic effect on plants and Khomchenko. (IG Ryb, AV Trifonov, BN Razuvaev. "Modern aquarium and the Phenomenon"). the chemistry of antagonism is also found between Fe and Ca, Al and Na, Fe and Zn, Mn and Zn, Cu and Zn, Zn and Fe.
simple of one way to reduce the concentration of abundant elements - nutritional water change, provided that the water is poured into that there is no excess of these however. elements, this method will not be effective for all elements. According to the table "Change in the concentration of aquarium microelements in water" (IG Khomchenko, AVTrifonov, BNRazuvaev) that, the concentration of some trace elements (manganese, quickly, etc.), copper drops after application.
On the one hand, this is due to the rapid absorption by plants, with the formation of insoluble salts or complex organic salts with compounds by the substrate in the soil on the other. Poorly soluble phosphates can also accumulate in the soil. In these cases, there will be no output of an effective excess of batteries when replacing the next one.
Therefore, the most reliable and helpful way to avoid an overdose is an accurate calculation of fertilizers without exceeding the recommended doses and careful observation of plants.