Lack of nutrients in plants. Lack or excess of elements in a plant
Lack and excess of nitrogen
Nitrogen deficiency It is most pronounced on older lower leaves from the very beginning of the growing season of the indicator plants: strawberries, apple trees, potatoes, and tomatoes.
Leaves shrink from pome crops, they become narrow, losing a rich green color. Orange and red dots appear on the pale green leaves. The leaves turn yellow, fall prematurely. Roses in the spring are particularly sensitive to nitrogen deficiency. A weak growth of shoots is observed, the flowering of the plant weakens, and the wood of the stems does not mature well. Strawberries have a bad mustache.
Nitrogen starvation of plants can increase due to the increased acidity of the soil and the sodding of its surface under fruit trees.
With an excess of nitrogen foliage becomes dark green in color. Plants begin to thrive, but their stems are soft, little flowers are formed. Plants are easily affected by fungal diseases. Excess nitrogen fertilizers lead to the development of chlorosis along the edges of the leaves and between the veins, brown necrotic spots appear on them, the ends of the leaves curl.
Lack and excess of phosphorus
Phosphorus deficiency Most clearly manifested in the older lower leaves of indicator plants, such as: peach, apple, strawberry, black currant and tomato.
The leaves are dull dark green with red or purple or bronze tint. Red and violet-brown stripes and spots may appear at the edges of the leaves, as well as near the petioles and veins. Stalks, leaf stalks and veins also become purple.
Leaves shrink, become narrow, move away from shoots at an acute angle, dry and fall. Early fall of the leaves, the drying leaves darken, sometimes even turn black. Flowering and fruit ripening is delayed. Plants lose their decorative effect.
The growth of shoots slows down, they bend and weaken, often shoots are blind. The root system is developing poorly, root growth is delayed. In general, winter hardiness of plants decreases.
Organic fertilizers have a beneficial effect on the composition of the soil, improve its permeability to water and air, stabilize the soil structure. In the process of decomposition in the ground, organic fertilizers form a layer of soil humus, which increases its fertility.
Symptoms of phosphorus starvation of plants most often noted on acidic light soils with low organic content.
Excess phosphorus leads to salinization of soil and manganese deficiency. In addition, the plant loses the ability to absorb iron and copper, as a result of the metabolism is broken. In plants that have received an excess of phosphorus, the leaves become shallow, dull, curl, and covered with growths. Plant stems harden.
Lack and excess of potassium
Sign of potassium deficiency more pronounced in the middle of the growing season on the older lower leaves of the indicator plants: strawberries, raspberries, currants, tomatoes and beets.
The symptoms of potassium deficiency are first manifested by blanching the leaves. Leaf color is dull, bluish-green. There is an uneven growth of leaf blades, the leaves are made shriveled, sometimes the curliness of the leaves is noted. The edges of the leaves fall down. The leaves turn yellow, starting at the top, but the veins remain green. Gradually the leaves turn yellow completely and acquire a reddish-purple color.
This phenomenon is observed in black currants, whose leaves with a lack of potassium become purple with an edge burn. The marginal “burn” at the edges of the leaves is the rim of the drying fabric, then the leaves dry out.
The plant is stunted with short internodes, shoots grow thin and weak.
Young leaves of a rose get a reddish shade, with brown edges. Flowers in plants are small. This phenomenon is often noted in roses growing on sandy and peaty soils, where the roses lack potassium. First, the lower leaves die off, then the process moves to the young leaves, they turn black. As the process continues, the stalks of roses die.
Signs of potassium starvation can be most clearly manifested in soils with a high level of acidity, as well as on those soils in which excessive doses of calcium and magnesium were introduced.
Excess potassium causes a delay in plant development. The leaves of the plant, overfed with potassium, become light green in color, and spots appear on them. At first, leaf growth slows down, then they wither and fall.
Calcium deficiency and oversupply
Calcium is needed by plants for the normal development of the aerial parts and the growth of roots, in nature it is found in the form of limestone, chalk and other compounds. Sign of calcium deficiency most clearly manifested in the older lower leaves, at the beginning of the growing season on young tissues, on the tops of the shoots of indicator plants, such as: strawberries, gooseberries, currants, cucumbers and cabbage.
Calcium deficiency results in a change in the color of young leaves - they turn white and crochet upwards. Sometimes the leaves have a ragged appearance.
Stems and leaves are weakened, they can die off growing points, flower stalks and shoot tips, leaves and ovaries fall. The shoots themselves thicken, but in general the plant growth and the formation of new buds slow down. The root system is developing poorly, root growth is delayed.
Symptoms of calcium deficiency can occur on soils where there is an excess of potassium.
With calcium excess the shell of nuts and seeds of cherries and plums thickens, the leaves may turn yellow, because with an excess of calcium, the plant cannot but absorb iron. These signs are sometimes appear on potassium poor soils.
Iron deficiency and excess
Iron deficiency indicate yellowing and partial or complete leaf discoloration (chlorosis). However, sometimes pale leaves indicate on excess calcium in the soil.
Yellowing of the leaves begins at their edges, young leaves suffer the most. But around the veins there is still a narrow green stripe. As chlorosis progresses, small veins become discolored. Then the sheet becomes almost white or acquires a white-cream color. Then the edges of the leaves die off, then the leaf tissues die off completely and they fall prematurely.
In plants weakened by chlorosis, growth slows down, the tops of the trees can dry out, the fruits become smaller and the harvest sharply decreases.
Very often, plants lack iron on neutral, alkaline and calcium-saturated soils. It happens and with excessive soil limingwhen the iron in the soil becomes bound, which can cause chlorosis.
Magnesium deficiency and excess
Lack of magnesium Most clearly manifested in the older lower leaves, often in the middle of the growing season, especially during drought on indicator plants: potatoes and tomatoes. It is expressed in the development of interstitial chlorosis of the leaves, their color becomes similar to the “herringbone”. First, on the old leaves, and then on the young in the middle of summer, discolored spots appear.
The leaves become yellow, red or purple in color, since dead dark red areas and dying reddish-yellow zones appear between the veins. But the edges of the leaves and veins remain green for some time. They begin to fall prematurely, and the early leaf fall begins at the bottom of the plant. Sometimes, due to the lack of magnesium on the leaves, there is a pattern similar to the symptoms of a mosaic disease of plants. The edges of the leaves of gooseberry stripes painted red. Often the lack of magnesium leads to a decrease in winter hardiness and freezing of plants.
The symptoms of magnesium deficiency are most pronounced. on light acid soils, especially in roses, growing on acidic soils. Often magnesium shortage enhance the continuous potash fertilizers. If magnesium compounds in soil in excess, the roots of the plants are poorly absorbed by potassium.
Boron deficiency and oversupply
Boron boosts pollen growth, affects the development of ovaries, seeds and fruits. A sufficient content of boron in plant nutrition contributes to the influx of sugars to plant growth points, flowers, roots and ovaries.
Symptoms of boron deficiency most often occur on the younger parts of the indicator plants, tomatoes, beets. Symptoms are especially pronounced during drought.
The lack of boron affects the growth point of young shoots. With prolonged boron fasting, it dies. Often there is a slow development of the apical buds with enhanced development of the lateral ones.
The chlorosis of young leaves develops: the light green leaves become smaller, their edges bend upwards and the leaves curl. Young leaves turn yellow veins. Later on such leaves appears regional and apical necrosis.
With a lack of boron, the growth of the whole plant is inhibited. On the shoots die small areas of the bark, the tops of the shoots can die off (dry top). There is a weak flowering and fruit set, which take on an ugly shape.
The application of organic fertilizers increases the content of nutrients in the soil, contributes to the regulation of biological processes in it and activates the activity of soil microorganisms.
Fabrics of pome fruit gain cork structure. On the cauliflower the glassiness of the heads is manifested, and in the beet the core rots.
Most often, starvation of plants occurs on calcareous soils.
Over-application of boron-containing fertilizers accelerates the ripening of fruits, but their keeping quality also suffers.
Lack and excess of manganese
Signs of a shortage of manganese in the soil, first of all they appear on the upper leaves, in their bases of the indicator plants: potato, cabbage and beet.
White, light green, red spots appear the same as in magnesium fasting, but not on the lower, but on the upper, young leaves.
Injured plants develop interstitial chlorosis, the leaves turn yellow between the veins from the edge to the center, forming areas in the form of a tongue. In this case, the leaf veins for a long time may remain green, around the veins a green rim is formed. Sometimes a lack of manganese causes brown leaf spot.
With an excess of manganese iron passes into the oxide form, which is poison for the plant. To avoid such problems it is necessary to make iron four times more than manganese. This is the ratio that is beneficial for the plant.
With an excess of magnesium the plant shows signs of calcium deficiency.
Copper deficiency and oversupply
Signs of copper deficiency Most clearly manifested in the younger parts of the plant-indicators - lettuce and spinach. These symptoms are especially pronounced during drought.
The plants are stunted, the apical bud dies off, and the lateral buds awaken at the same time. Then on the tops of the shoots appear rosettes of small leaves.
The tips of the leaves turn white, the leaves themselves become variegated. Sluggish and ugly, they become pale green with brown spots, but without yellowing. The veins of the leaf stand out sharply against this background. Young leaves lose turgor and fade.
If the soil is present excess copper, the plants often suffer from iron deficiency.
Lack and excess of molybdenum
More often than others molybdenum deficiency celebrated in cauliflower grown on acidic sandy (less clay) soils. This symptom it appears brighter if physiologically acidic fertilizers are used. Therefore, it is not recommended to use excessively peat for growing seedlings.
Symptoms of starvation are manifested in the dying off of the growth point, as well as in the abscission of buds and flowers. Leaf plates can not develop to the end, the cauliflower head is almost not tied. Older leaves become colored as with chlorosis. In the later stages of development, the lack of molybdenum in cauliflower causes deformation of young leaves. The resistance of early varieties to this problem is much weaker compared with late varieties.
The most common lack of molybdenum is manifested on swampy soils, in the cold or dry period, with an excess of nitrogen.
Excess molybdenum leads to a violation of the digestibility of copper.
Lack and excess of sulfur
Sulfur affects the redox processes in plant tissues, contributing to the dissolution of mineral compounds from the soil.
With a shortage of sulfur the leaves become light green in color, and the veins on the leaves become even lighter. Then red spots of dying tissue appear on them.
With an excess of sulfur the leaves gradually turn yellow from the edges and shrink, turning inside. Then turn brown and die. Sometimes the leaves take not yellow, but a lilac-brown shade.
Deficiency and excess of zinc
Symptoms of zinc deficiency they usually appear on old leaves (especially in spring) of indicator plants: tomatoes, pumpkin and beans.
Symptoms first appear on the leaves, they are small, shriveled, narrow and speckled because of interstitial chlorosis. Green color remains only along the veins. Often on the sheet at the edges and between the veins appear dead areas.
Zinc deficiency usually manifested on nitrogen-rich soils.
Signs of elevated zinc are watery transparent spots on the lower leaves of plants along the main vein. On the leaf plate there are outgrowths of irregular shape, after some time, tissue necrosis occurs and the leaves fall.
Nutrient Excess
An excess, like a deficiency, of nutrients leads to a disturbance of biochemical processes in the plant. Signs of poisoning plants with certain substances often coincide with the symptoms of a lack of certain nutrients.
Nitrogen
With an excess flow of nitrogen into the plant, there is a delay in flowering and maturation. Externally, the overfed plant has dark green foliage, an overly thick stem. The growing season is extended, the tissues become juicy and soft, more susceptible to fungal diseases.
In a cucumber with an excess of nitrogen the leaves turn dark green. Middle and old leaves bend. Transparent spots between the veins merge and become yellow or gray-brown. Fruits are smaller than usual, they accumulate more nitrates. With a strong nitrogen poisoning plants die within a few days. Excess nitrogen retards potassium uptake by the plant.
Phosphorus
Excess phosphorus in the plant leads to a general yellowing, bright necrotic spots appear, leaves fall. The development of the plant accelerates, it quickly ages. High doses of phosphorus increase the sensitivity of the plant to water deficiency. Excess phosphorus retards potassium uptake by the plant.
Potassium
With an excess of potassium, nitrogen is delayed in the plant. Its accumulation in tissues leads to a delay in plant growth. The internodes lengthen, the leaves brighten. In later phases, mosaic spots appear on the leaves. Leaves wither and fall off. Damage is local, necrotic tissue. Excess potassium impairs the absorption of magnesium or calcium (especially with high acidity of the soil).
Magnesium
If there is a lot of magnesium in the soil, the leaves of the plants sometimes become darker and curl.
Calcium
Excess calcium causes interstitial leaf chlorosis. The spots are pale, necrotic, sometimes concentric circles filled with water appear on them. With an excess of calcium, the availability of trace elements such as boron and manganese for plants decreases.
Copper
An excess of copper leads to chlorosis on the lower leaves, then to the formation of brown spots and leaf fall. Interstitial chlorosis of young leaves is also noted.
Manganese
The veins of old cucumber leaves with an excess of manganese become dark red, between them appear light green or transparent spots. Necrosis gradually develops, the leaves die. With a strong manganese poisoning, plant growth stops, cuttings and leaves are covered with a mass of dark red dots. The development goes from older to younger leaves. You can not get involved in frequent spraying and dressing under the root of potassium permanganate.
Boron
With the accumulation of boron in the soil at the edges of the lower leaves of cucumbers, a yellow stripe appears, the leaves are wrapped down and take a dome-shaped form. Harvest is declining.
Chlorine
With an excess of chlorine leaves coarsen, become hard, small, but green. Stem hardens. On the old leaves of some plants appear purple-brown spots, then the leaves fall.
Excess, like deficiency, of nutrients leads to disruption of biochemical processes in the plant, for example, growth slows down, tissues die. Signs of poisoning plants with certain substances often coincide with the symptoms of a lack of certain nutrients.
With excess admission nitrogen flowering and maturation are delayed in the plant. Externally, the overfed plant has a dark green tops, an overly thick stalk. The growing season is extended.
Due to the accumulation of organic forms of nitrogen compounds, especially proteins, tissues become juicy and soft, more susceptible to fungal diseases and accessible to pests. The product quality of many cultures is deteriorating.
Tomatoes are signs of excess nitrogen similar in many ways to potassium deficiency. Chlorosis develops first along the edges of the leaves, then between the veins and is accompanied by brown necrosis. At the same time, the ends of the leaves roll up at the edges, the stalks also bend.
Cucumber with excess nitrogen leaves turn dark green. Middle and old leaves bend. Transparent spots between the veins merge and become yellow or gray-brown. Fruits are smaller than usual, they accumulate more nitrates. With a strong nitrogen poisoning plants die within a few days.
Excess phosphorus when growing vegetable crops, it leads to a general yellowing of the plants, bright necrotic spots appear on them, leaves fall. The development of plants accelerates, they quickly grow old. High doses of phosphorus increase the sensitivity of plants to water deficiency.
In some plants, symptoms of excess phosphorus similar to signs of potassium starvation, in others - to signs of excess nitrogen. The ends and edges of older tomato leaves become yellowish or brown, necrotic spots sometimes appear on them, but the leaf tissue remains intact.
With an excess potassium nitrogen is delayed in the plant. Its accumulation in tissues leads to a delay in plant growth. The internodes lengthen, the leaves brighten. In later phases, mosaic spots appear on the leaves. Leaves wither and fall off. Damage is local, necrotic tissue.
If there is a lot of soil magnesium, the leaves of plants sometimes become darker, curled. In tomato, they are slightly reduced in size, then their ends are drawn out and die.
Excess calcium causes interstitial chlorosis of leaves. The spots are pale, necrotic, sometimes concentric circles filled with water appear on them. On some plants, enhanced leaf growth begins, but the shoots die off.
Signs of plant poisoning are similar to the symptoms of magnesium or iron deficiency. On tomatoes, chlorosis develops in the form of whitish necrotic spots, which can be colored, with concentric rings filled with water.
Very carefully it is necessary to make trace elements! There is a rather small interval between the indicators of deficiency and excess. The symptoms of this and other phenomena are the same. For example, with an excess and with a deficit between the veins, chlorosis develops, later the leaves turn yellow and turn pale. Diseased plants either do not give a complete harvest, or give a very low.
Excess copper leads to chlorosis on the lower leaves, then to the formation of brown spots and leaf fall. Interstitial chlorosis of young leaves is also noted.
If there is a lot of soil manganese, between the veins of young leaves chlorosis appears, various necrotic spots. The leaves are bent, shriveled and poured. The development of the disease goes from older to younger leaves. You can not get involved in frequent spraying and dressing under the root of potassium permanganate.
Veins of old cucumber leaves with excess manganese become dark red, between them appear light green or transparent spots. Necrosis gradually develops, the leaves die. The lesion spreads from the bottom up through the plant. With a strong manganese poisoning, plant growth stops, cuttings and leaves are covered with a mass of dark red dots.
In greenhouses are widely used fertilizing boric fertilizer. When accumulating bora a yellow strip appears in the soil at the edges of the lower leaves of the cucumbers, the leaves turn down and take a dome-shaped shape. Harvest is declining.
Very sensitive to excess bora potatoes. The edges of the leaf slices turn yellow and are wrapped up in a boat, starting from the lower tier.
On excess bora Tomatoes react. Old leaves usually suffer, on which depressed dry spots bordered by concentric circles develop. The curved lobes of the leaves become dry as paper. The top of the plant first has a normal appearance, then curls along with the damaged leaves.
To help the plant in this case can be abundant watering. Boron It binds poorly to the soil and is easily washed into the lower layers. Adding to peat or humus plants is useful in greenhouses, which will cause the formation of additional roots.
Remember: boron - It is a carcinogen, its content in the soil should not exceed 1.5-2 mg per 1 kg of soil for cucumbers and 2-2.5 kg for tomatoes.
Some plants have excess zinc leads to transparent areas at the base of the main veins, which remain green. Chlorosis develops between the veins. Upper buds die off, old leaves fall off without signs of wilting. The veins on them are painted red or black. The early stage of poisoning is similar to signs of iron deficiency.
In tomatoes, the stem becomes thinner, the plants do not grow well, and the leaves are unusually small. Inter-vein necrosis develops, the lower side of the leaves becomes purple, the old leaves are strongly bent down, the lower side is colored purple from the edges to the center.
Cucumber plants lag far behind in growth. Chlorosis appears on the youngest, resembling iron deficiency. Later, these symptoms spread to old leaves.
With an excess chlorine leaves grow coarse, become rigid, small, but green. Stem hardens. On the old leaves of some plants appear purple-brown spots, then the leaves fall.
In tomatoes, the leaves become dull green, the stems harden. Signs of potato chlorine poisoning appear during or after flowering. The stalk thickens, remains short, the leaves roll along in a boat along, later a light brown rim of dying tissue appears at their edges. The leaves wither and the tubers lose their starch.
Typically, these signs appear along with signs of nitrogen deficiency. In this case, fertilizing with ammonium nitrate at the rate of 10-20 g per 1 m 2 with subsequent irrigation helps. The harmful effects of chlorine can be reduced by the addition of magnesium.
There are no special remedies for excess nutrients. It can be prevented by strictly observing the agrotechnology of vegetable crops and especially the system of mineral fertilizer application.
Bibliography
- An excess of nutrients is also bad / A.T. Lebedeva // Family. Land. Harvest - 2002. - № 9. - p. 2-3.
As mentioned earlier, neither organic compounds already present in the soil, nor industrial fertilizers added to the soil, are a true food for plants. Plants simply use this raw material to produce carbohydrates, fats and proteins. These complex organic substances are the source of nutrition and energy for the plant. There are 16 essential nutrients for plants. These include the following elements, usually found in the soil: iron, copper, zinc, manganese, calcium, nitrogen, phosphorus, sulfur, magnesium, chlorine, boron, and molybdenum (see lecture.
None of the 17 essential elements required by a plant can be absorbed by plants in its elemental form. Before the plant can use them, these elements must react with other elements, must be converted to oxidized or reduced forms. Here are the properties of some elements:
Pure nitrogen is an inert gas and cannot be used by plants.
Pure phosphorus, when in contact with air, ignites spontaneously and cannot be used by plants.
Pure metallic potassium should be stored under a layer of kerosene to prevent its oxidation. Potassium is rapidly oxidized in air and, when combined with water, forms a caustic compound, caustic soda. Consequently, commercially available industrial fertilizers are compounds of nitrogen, phosphorus and potassium.
Plants absorb nutrients in the form of inorganic salts (compounds) dissolved in water. Therefore, for plants there is no difference what kind of fertilizers are used: industrial fertilizers or such organic materials as animal dung, compost, and plant (crop) residues. It is really important to maintain plant growth and harvest is another - it is important that plants receive the necessary nutrients in the exact and correct ratio.
Recently, in a number of regions, more and more farmers are facing a deficit of cobalt. This is the seventeenth element, absolutely necessary for plants. It is required in macroscopic quantities, and often enough of the amount of cobalt, which is introduced in the form of impurities with basic fertilizers. However, growers must be prepared to make this trace element as soon as the need arises.
For chemists, the minerals found in rocks or their fragments are chemicals or chemical compounds. Others call these compounds minerals. For the most part, chemical fertilizers and minerals are in various concentrations in the soil and rocks.
SOURCES OF FERTILIZERS
Of the 17 nutrients required by plants, 13 are mined from rocks. These are potassium, phosphorus, magnesium, sulfur, manganese, boron, calcium, zinc, copper, iron, molybdenum, cobalt and chlorine. Three batteries come from air and water: carbon, hydrogen and oxygen. One element, nitrogen, initially comes from the air through complex biological or chemical fixation and eventually returns to the air when the cycle ends.
The rotting and rotting organic materials found in the soil are a possible source of nitrogen that plants can use. Currently, industrial nitrogen fertilizers are produced from by-products from the processing of fossil fuels and from the atmosphere.
COMPARISON OF GARDENING IN ORGANIC AND GARDENING WITH THE USE OF INORGANIC FERTILIZERS
Does Dr. Mittlider practice gardening on organic matter and believing in it? Those who grow vegetables exclusively on organics usually adhere to the following dogmas:
Inorganic (chemical) fertilizers and pesticides poison the soil and soil organisms.
Vegetables grown with the use of inorganic fertilizers and pesticides are harmful to people, in any case less useful than vegetables grown only with the use of organic fertilizers.
People who advocate gardening on organics usually declare the exceptional and extraordinary merits of natural organic sources.
Dr. Mittlayder believes:
Regardless of how the soil is fertilized, whether composted with organic matter or industrial fertilizer, the elements used by the plants are the same. At the molecular level, nitrogen is nitrogen, regardless of its origin. Plants use the same chemical process to convert starting materials into carbohydrates, proteins, and fats, regardless of whether they are derived from a chemical or organic source.
The batteries used by Dr. Mittlider are from industrial sources. Substances in most industrial fertilizers are found in natural soil and are extracted from rocks. Then these fertilizers are packaged and sold.
There is no evidence to support the opinion that the use of industrial fertilizers is harmful to health. On the contrary, people live longer and have better health where such fertilizers are used.
Usually, Dr. Mittlider does not teach students some agrotechnical techniques, such as composting, because it is difficult to determine how many specific nutrients are contained in organic materials. Whatever fertilizer is used, it is necessary to know exactly which batteries are applied with this fertilizer and in what quantity.
Such techniques as composting often lead to other complications for plants: to diseases, rot, excessive development of weeds. Pesticide use can be minimized by using the gardening methods outlined in this course. Dr. Mittlider’s gardens are very clean and do not attract many insects. However, situations arise (see Lecture 6) when it is difficult to offer an alternative to the use of pesticides that could save yields. In such situations, care must be taken when using pesticides and be guided by the accompanying instructions.
HOW FERTILIZERS ARE PASSENGED AND SOLD
Everywhere in the world, fertilizers are sold with standard labels. The marking on fertilizer 10-10-10 means that it contains 10% nitrogen, 10% phosphorus and 10% potassium.
In total, this gives 30% of plant nutrients. Consequently, 100 kg of fertilizer 10-10-10 (K-PK) contain 10 kg of nitrogen, 10 kg of phosphorus (in terms of P2O5) and 10 kg of potassium (in terms of K20), which is in the amount of 30 kg of 100 kg.
Packed fertilizer
The remaining 70% (70kg out of 100 kg) consists of accompanying ions and inert materials that serve as carriers and fillers. For example, in potassium sulfate, the weight of sulfate
ion is part of the considered 70%. Actual quantities of K-PK batteries are always indicated on the bags with fertilizer. Similarly, a 21% nitrogen label will appear on the ammonium sulphate bag, meaning that 100 kg of fertilizer contains 21 kg of nitrogen.
If you need to add 170 kg of nitrogen per hectare of land, remember that every 100 kg of fertilizer contains only 21 kg of nitrogen. To get 170 kg of nitrogen (with a nitrogen content of 21 kg per 100 kg of fertilizer), you will have to purchase 809 kg of fertilizer.
The urea fertilizer, labeled 46% nitrogen, contains 46 kg of nitrogen in every 100 kg of fertilizer. If it is required to deposit 170 kg of nitrogen per hectare, then a farmer who uses urea will need to purchase (170: 46) x 100 = 370 kg of urea for application per hectare.
WHY NEED TO FERTILIZE?
Together with each crop a certain amount of nutrients is taken out of the soil. For example, from one hectare at a corn yield of 90 c / ha along with the crop: 260 kg of nitrogen, 100 kg of phosphate (P205), 200 kg of potassium (K2O), 27 kg of sulfur, 44 kg of magnesium, 55 kg of calcium, 2.7 kg of iron , 2.2 kg of manganese, 1.1 kg of boron, 550 g of zinc, 110 g of copper.
This amount of nutrients is removed from a hectare of soil with a corn yield of 90 c / ha
Rain and erosion cause additional soil depletion. Soils cannot always be restored simply by adding organic materials. Although organic materials such as animal manure or green manure (green manure) are very useful, the fact remains that they do not always fully restore the balance of nutrients in the soil. Due to their uncertain composition, it is impossible to fully rely on organic materials to compensate for nutrient deficiencies in the soil.
HIDDEN HUNGER
When plants do not detect any obvious symptoms of starvation, but they do not grow as they should, because the level of available nutrients in the soil limits their growth, then the plants suffer from hidden hunger. For example, a field of corn for latent starvation can only give 19-30 centners of corn, while well-fed plants in the same field can yield from 45 to 55 centners of corn. Hidden hunger greatly reduces the quality and quantity of the crop.
(arrows: up - increase in productivity, to the right - increase in soil fertility)
With the hidden hunger of plants it is impossible to achieve maximum results.
HOW DO FERTILIZERS
The Earth cannot produce more than what its main limiting factor allows, be it fertilizer, water, heat or sunlight. Plants will even grow more or less satisfactorily over a wide range of fertilizer shortages, provided that the content of all fertilizers is equally low. The key to this phenomenon is the limiting factor. For example, if there are no fertilizer deficiencies that limit plant growth in a one-hectare field and all the necessary factors are in place to get a good harvest, 100 hectares of cabbage will be obtained from this hectare. However, if one of the fertilizers (one nutrient) is too small, then this nutrient becomes the limiting factor and will inhibit plant growth. The harvest will be no more than this limiting factor will allow. Suppose that in our case the first limiting factor is phosphorus. Soil contains only 1/8 of the required amount of phosphorus. This means that if
fertilizers will not be applied, the yield per hectare of land will not exceed 12.5 tons (100: 8 = 12.5).
The most limiting factor is phosphorus.
To eliminate this obstacle and make the farm more profitable, the farmer scatters 330 kg of double superphosphate over his land. Due to the introduction of superphosphate, the farmer eliminated phosphorus deficiency, and now phosphorus is no longer the limiting factor. The harvest reaches 50% of the maximum possible level of the ^ -th, i.e. 50 tons. By applying fertilizer, the farmer increased his crop by 37.5 tons.
This is close to a potential yield of 100 t / ha, however, the farmer seeks to achieve the highest yield. The next fertilizer he introduces is 330 kg of potassium chloride. Having taken this step, the farmer discovers that his harvest has increased to 75 tons. The increase in yield made the purchase of potassium a reasonable investment.
Inspired by the success, the farmer strives for even greater yield. A farmer purchases fertilizer marked 16-8-16. This means that the fertilizer contains 16% nitrogen, 8% phosphorus and 16% potassium. The farmer contributes an additional 440 kg of this fertilizer per hectare of land. But does the earth require this type of fertilizer? In fact, the next limiting factor may be calcium, not nitrogen, phosphorus, or potassium.
Now the most limiting factor is calcium.
Since calcium is now a factor that limits the yield, fertilizer application 16-8-16 was a mistake; This fertilizer does not contain calcium and therefore will not give an increase in yield. In fact, the farmer embarked on a risky path leading to lower yields. To understand why this is so, we must first get a general idea of osmosis.
Osmosis occurs when the salt solution moves through a semipermeable membrane from a region with a lower salt concentration to a region with a higher salt concentration. For example, if a vessel is divided in half with a watertight partition and water is poured from one side, and on the other hand the exact same volume of concentrated sugar solution, then no movement of the liquid between the solutions occurs, because the wall is not permeable to liquid. However, if the wall between the two liquids is semi-permeable, then the water will be drawn out with a concentrated sugar solution. The level of the sugar solution will rise, and the water level will drop, and in the end all the water will be dragged into the sugar solution.
Let's do this experience. Take an apple. Peel the skin. Cut an apple into four or more lobules. Then we sprinkle the slices of the peeled apple with sugar (or salt). Slices from all sides should be covered with sugar.
What will we see?
After 5 minutes - the sugar on the peeled pieces will begin to dissolve.
After 10 minutes - drops of apple juice will drip off the slices.
After 4 hours, almost all the pit juice from the slices will drain out and only the pulp will remain.
This is the effect of osmosis. Sugar, being more concentrated, pulls out the juice from apple slices.
TOO BIG NUMBER OF FERTILIZERS MAY BE CAUSE OF THE DEATH OF AGRICULTURAL CULTURES
In the example above, 440 kg of fertilizer 16-8-16 were scattered per hectare of land. This did not lead to an increase in yield. Since all the ingredients were salts, this means that hundreds of kilograms of real salts were scattered on a hectare of land. The plants did not need these salts and could not use them.
In exceptional cases, excess salts can lead to complete loss of the crop, but in any case they are harmful to it. Excess fertilizer will lead to a decrease in yield rather than an increase in yield. This is because plants absorb nutrients and water from the soil solution due to osmosis. This means that the solution in the plant (juice) must be more saline than the soil solution. If the salt concentrations in the soil solution and in the solution in the plant are the same, the plant will stop absorbing water from the soil.
If the concentration of salts in the soil solution is higher than the concentration of salts in the plant sap, the soil solution will draw the liquid from the plants. Then the plant will wither, and if it is not saved, it will die. To clarify how this happens, suppose that the farmer sees that the condition of his plants is deteriorating. He makes a very serious mistake by assuming that more fertilizer is needed. A farmer purchases urea and scatters 200 kg of salts on the ground, which is already over-fermented. Previously, the farmer brought 440 kg of excess salt to the ground. Now, after adding another 200 kg, it has an excess of salts in the amount of 640 kg. This is enough not only to reduce the harvest, but also to dehydrate the plants (draw moisture out of them), cause wilting, and possibly even the death of the crop.
This example clearly shows what can happen when fertilizers are used carelessly. When applying fertilizers, it is dangerous to be guided only by well-intentioned and vague guesses. If fertilizers kill plants, this is not because the substances are poisonous. Fertilizers are nothing more than the raw materials from which plants create the nutrients they need. The percentage of substances marked on the bags with fertilizers indicates that these are concentrated substances. If they are made accurately, in the right proportions and at the right time, the result will be high quality, high yield and profitable crops. Guessing can turn into disappointment and even prove fatal for the crops grown.
NAMES OF USUALLY APPLIED FERTILIZERS
NITROGEN Ammonium nitrate (ammonium nitrate)
Ammonium sulphate - also contains sulfur
Calcium nitrate (calcium nitrate) - also contains calcium
Diammonium phosphate - also contains phosphorus
Urea Liquid ammonia
Potassium nitrate (potassium nitrate) - also
contains potassium
PHOSPHORUS Diammonium Phosphate - also contains nitrogen.
Simple superphosphate - also contains
sulfur and calcium
Double and triple superphosphates
Phosphoric acid
Monoammonium phosphate - also contains nitrogen
Potassium Potassium Chloride - also contains chlorine
Potassium sulfate - also contains sulfur
Potassium nitrate (potassium nitrate) -
also contains nitrogen
Calcium Calcium sulphate (gypsum) - also contains
Calcium carbonate (lime)
Dolomitic lime - also contains
Calcium nitrate (calcium nitrate) -
also contains nitrogen
Calcium chloride - also contains chlorine
MAGNESIUM Sulphate of magnesium (bitter or English salt) - also contains sulfur
Magnesium Oxide (burnt magnesia)
Dolomitic lime - also contains calcium
SERA Simple superphosphate - also contains calcium and phosphorus.
Ammonium sulfate - also contains nitrogen.
Potassium sulfate - also contains potassium
Magnesium sulfate - also contains magnesium.
Ferrous sulphate - also contains iron
Calcium sulphate (gypsum) - also contains calcium
BOR Boric acid
Sodium borate (borax)
IRON Iron sulfate - also contains sulfur
Iron chelates
Manganese manganese sulphate - also contains sulfur
Manganese oxide
COPPER Copper sulphate (blue vitriol) -
also contains sulfur
Zinc Sulfate zinc (zinc vitriol) -
also contains sulfur
Zinc oxide
Zinc chelates
Molybdenum sodium molybdate - also contains sodium
Ammonium Molybdate - also contains nitrogen
Molybdic acid
LEARN TO USE FERTILIZERS
Learning how to properly use fertilizers is not so difficult and difficult as it may seem at first glance. During the long years of research on plants and their nutritional needs, many difficult problems have been solved. Trustworthy information has become available regarding the amount of fertilizer that different crops carry per unit area for one growing season.
Well-known signs of a lack of each of the plant nutrients. Plants always detect symptoms of nutritional deficiencies before the crop is seriously damaged. Plants also indicate an excess of nutrients. Healthy plants are also recognized by their healthy appearance. You can learn how to grow healthy plants if you learn good technology and intelligently follow it in practice.
Take the time to get to know the plants better. Learn the language of plants by studying them and observing them carefully, day after day. If plants develop nutritional deficiencies, they will show it to you. Avoid excessive fertilization. If you made a mistake and made extra fertilizer, water the soil once with plenty of water to wash the fertilizer from the topsoil to a depth of less than 20 cm, and plant the plants again. After the next crop has been planted, with a few next waterings, let the excess water to keep the fertilizer at a depth of 20 cm or less. If you follow this procedure, the results are usually good. The correct fertilization depends on the weighing accuracy. Every person should develop a good accounting system that is clear to him.
CHECK YOUR KNOWLEDGE
Choose the correct answer:
1. “Hidden hunger” in plants implies
a) visible signs of fasting
b) excessive fertilization
c) no visible signs of starvation, but reduced yield
d) none of the above.
2. If the farmer needs 33 kg of nitrogen, how much fertilizer does the farmer need to buy 34-0-0?
a) 45 kg c) 135 kg
b) 90 kg g) 180 kg
3. What will you do if you apply too much fertilizer?
a) add lime to the soil
b) pour plenty of water to wash excess fertilizer
c) add sawdust or sand to the soil
d) remove the culture and start all over again.
1. In order to achieve the fastest possible growth and maximum yield, the plants must receive an exact amount of the necessary nutrients in a properly balanced ratio.
2. Many industrial fertilizers are mined from the ground. Industrial fertilizers are easy to use because you can determine exactly how much each battery should be applied.
3. It does not matter to the plant whether you use organic or inorganic fertilizers, in either case, the plants absorb the nutrients in the form of inorganic salts dissolved in water.
4. When the fertilizer is solid, most of it consists of inert materials. The actual amount of fertilizer is indicated in percent of the total weight.
5. Soils require constant replenishment. The removal of nutrients to the crop, rain and erosion are the reason that the soils are depleted. But if nutrients are replenished, the soil is never depleted.
6. Plants may not detect any visible signs of nutritional deficiencies, already suffering from “hidden hunger”. If one or more batteries are missing, the crop will not be able to reach maximum sizes. Production volume will reach the level determined by the most limiting factor.
7. Excessive fertilizer is harmful to plants and can destroy the crop. If the soil is too saline, water will be pulled out of the plants.
