Fertilizers. Classification of fertilizers.

Mineral fertilizers are applied to the replenishment of soil nutrients, such as phosphorus (P), potassium (K), nitrogen (N). If these fertilizers are applied separately - they are called simple (ammonium nitrate (N), superphosphate (P), potassium chloride (K)). When you make a mixture of fertilizer can be used, but this greatly complicates the preparation for the introduction of and degrades the quality of their distribution in the field. So widespread complex fertilizers (nitrophoska (phosphorus, nitrogen and potassium) and ammonium phosphate (phosphorus and nitrogen)).

Nitrogen fertilizers

Available in three forms: ammonia (ammonium sulfate), nitrate (ammonium nitrate), amide (urea). Form of nitrogen determines the terms of fertilizer and equipment. Ammonia is much easier absorbed by the roots with weak acidity of the soil, for a while fixed it. It can be made both in spring and late autumn. Nitrate-nitrogen soil is not fixed, it is in the form of a solution. Therefore, this fertilizer can be made only during the period from early spring to mid-summer. This fertilizer is easily absorbed by plants and is well suited for summer dressing. The amide is urea fertilizer. Nitrogen of this fertilizer this quickly (especially at elevated temperatures) goes into ammonium form. This fertilizer fast-performance. Used for fertilizing, slightly acidify the soil.

Phosphate fertilizers

According to the degree of solubility: soluble (simple and double superphosphate); semi-soluble - do not dissolve in water, but soluble in weak acids (precipitate); soluble in water, but soluble in weak acids (phosphate rock). Used on any water-soluble soils. When thoroughly mixed it with water, it is not required. Semi-soluble is sparingly and contribute mainly on acid soils. They become available to plants only after exposure to soil acidity. Make them in advance, trying to mix it with soil.

Potash

Like fertilizers applied concentrated chloride (potash) and sulfuric acid (potassium salt) salt. The whole thing are readily soluble in water. Potassium rather slowly penetrates deep into the soil, but still faster than phosphorus. At clay and loamy soils potash need to make in those layers of the soil, which has the bulk of fine roots to provide a rapid supply of potassium in them. At sandy soils, potassium is less than clay, so the need for potash hereinabove. At light soils and peat potash is applied fertilizers with autumn undesirable due to leaching of potassium.

Chlorine fertilizers

Sulphur, part of the sulfuric acid fertilizer is an element necessary to the plant. Chlorine is not needed. Therefore сhlorine-based fertilizers are injected in larger doses by autumn better. Autumn rains and the spring waters are washed chlorine from the deeper layers of the soil and chlorine does not harm the plants. In small doses, these fertilizers can be injected by spring.

Micronutrient Fertilizers (fertilizers containing boron, manganese, zinc, copper, molybdenum, etc.)

When using micronutrients is very important to establish the exact dosage because only drawback, but their excess is harmful to plants. Proper application of micronutrients protects plants from certain diseases (cork spot of apples, female disease, etc.) affects their growth and development on fruit set (strengthens the processes of fertilization, fruit formation), yield and fruit quality.

Pure chemical salts are used as microfertilizers, which can be purchased in stores, markets. In addition, the industry produces simple and complex fertilizers, including a number of individual micronutrients: superphosphate with boron, manganese, zinc ammonium phosphate, etc.

A long time in the practice of horticulture is established the possibility of introducing mineral nutrients in fruit trees directly through the leaves. This foliar nutrition is faster than a corresponding fertilizer introducing to soil, though less enduring. The best way to supply micronutrients is spraying their by respective salt solutions. Spraying is best done at night in cloudy weather, to not dry before it is absorbed by leaves.

Complex fertilizers

Complex fertilizers are divided to double composition (eg, nitrogen-phosphorus, nitrogen, potassium or phosphorus-potassium) and triple (nitrogen-phosphorus-potassium). According to the method of their production is divided by the complex slozhnosmeshannye (or combined), and mixed fertilizer.

Complicated fertilizers contain two or three nutrients as part of a single chemical compound. For example, ammonium phosphate - NH4H2PO4 potassium nitrate - KN03, magnesium - ammonium phosphate MgNH4PO4. The ratio between these nutrients in fertilizers is determined by the formula.

Complicated fertilizers or combined fertilizers are complex fertilizers produced in a single process into a single granule containing two or three basic elements of plant nutrition, albeit in the form of various chemical compounds. They are produced by special both chemical and physical processing of primary raw materials or different one-and two-component fertilizers. These include: nitrofos and nitrophoska, nitroammophos and NPK, ammonium polyphosphates and potassium karboammofosy, phosphorus-potassium fertilizer compressed, liquid complex fertilizers. The ratio between the nutrients in these fertilizers is determined by the amount of raw materials in their preparation for complex and compound fertilizer characterized by a high concentration of major nutrients and the absence of either a small amount of dietary fiber that provides significant savings of labor and money for their transportation, storage and use.

Assortment of complex fertilizers is mainly represented by the following forms: double nitrogen-phosphorus fertilizer - ammonium phosphate, and nitroammophos nitrofosy and double phosphorus-potassium fertilizer - potassium phosphate, ternary compound fertilizer - ammophoska, NPK and nitrophoska, magnesium ammonium phosphate.

Mixed fertilizers

Mixed fertilizers is a mixture of simple fertilizers produced in the factory or in blending plants at the field where using fertilizer by dry mixing.

Ammofos - concentrated complex phosphorus-nitrogen fertilizer prepared by neutralizing phosphoric acid with ammonia. Constitute the basis ammophos monoammonium NH4H2PO4 and partially DAP (NH4) 2HPO4. Little hygroscopic fertilizer, is highly soluble in water.

In the MAP, which is available in two grades - A and B, contains 9-11% N and 42-50% P2O5, ie the ratio of N: P2O5 in the fertilizer overly broad, equal to 1: 4 (nitrogen contained 4 times less than phosphorus). This highly concentrated fertilizer containing nitrogen and phosphorus in a well digestible plants, mainly water-soluble form. 1 quintal ammophos replaces at least 2.5 n simple superphosphate and ammonium nitrate 0.35 n.

Ammofos can be made as the main fertilizer in rows at sowing for all crops and fertilizer - under tilled crops, industrial crops and vegetables. The disadvantage of this fertilizer is that it contains nitrogen is significantly less than the phosphorus, whereas in practice they are likely to contribute in equal doses. Therefore, for normal ratio N and P2O5 ammophos necessary to add a certain amount of nitrogen fertilizer unilateral - NH4N03 or CO (NH2) 2. When making these fertilizers before planting of cotton and for winter crops and they can be used without the addition of nitrogen fertilizer, as in this case, the lack of nitrogen is compensated by nitrogen fertilizer top dressing.

Ammofos can be used directly as brought (ordinal) fertilizer for cotton, potatoes and cereals kultury. Rezults of many field experiments with different cultures and in different regions of the country showed that the efficiency of monoammonium phosphate (both single and supplemented nitrogen fertilizer) is usually higher than simple mixtures of fertilizers (superphosphate and ammonium nitrate), with equal standards of nitrogen and phosphorus.

Magnesium ammonium phosphate MgNH4PO4-H2O - triple complex fertilizer containing nitrogen 10-11%, 39-40% of available phosphorus and 15-16% magnesium. Fertilizer is sparingly soluble in water, slow-acting. However, the N, P and Mg available fertilizers for plants. Fertilizer can be applied as the basic for all crops in large doses without harm to plants. Effective fertilizer for growing vegetables in protected soil. Difficult mixed or combined fertilizers. Nitrofos and nitrophoska is respectively double and triple fertilizer get the decomposition of apatite or phosphorite with nitric acid. This produces calcium nitrate and dicalcium phosphate (with an admixture of calcium phosphate): Ca3 (PO4) 2 + 2H NO3 = Ca (N03) 2 + 2CaHPO4.

Nitroammophos and NPK

Fertilizer obtained under the basis of monoammonium phosphate are named like nitroammophos, when there is injected potassium then there is NPK . These complex fertilizers have higher than nitrophoska nutrient content and in their preparation has ample opportunity to change the relationship between N, P and K in their lineup. Nitroammophos may be created with the content and N 30-10% P2O5 27-14%. In total NPK nutrient content (N, P and K) is 51 % (in DM < A > - 17-17-17 and < B > - 13-19-19 ). Nutrients, not only nitrogen and potassium but also phosphorus contained in water-soluble form and are readily available to plants. Efficacy NPK is same as blends of simple water-soluble fertilizers.

NPK is injected as base fertilizer before planting as well as in rows or holes at planting and fertilizing. Its efficiency is almost the same as a mixture of equivalent amounts of ordinary fertilizers. NPK has a certain ratio of nitrogen, phosphorus and potassium as well as different soils differ in the content of individual nutrients and the need for them is not the same as plants, so inserting nitrophoska (as well as other complex and compound fertilizer) often need some adjustment. It is additional introduction of a given missing element in the form of ordinary fertilizers.

Liquid complex fertilizers

Liquid complex fertilizers (HCS) are obtained by the neutralization of ortho-and polyphosphoric acids ammonia with the addition of nitrogen solutions (urea ammonium nitrate) and chloride or potassium sulfate, and in some cases trace elements and salts. At saturation by ortho-phosphoric acid and ammonia is obtained ammophos DAP.

The total nutrient content of the liquid complex fertilizers based on phosphoric (or heat extracted acid) relatively low (24-30%) as in the more concentrated solutions at low temperatures, crystallization and loss of their salts precipitated. The ratio of nitrogen, phosphorus and potassium in the HCS may be different N-content of 5 to 10%, P2O5-5-H and K2O - 6 - 10%. In our country is produced mainly with HCS 9:9:9 ratio of nutrients as well as other aspect ratio (7: 14: 7, 6: 18: 6, 8, 24 0, etc.).

On the basis of polyphosphoric acid was prepared HCS with higher total nutrient content (over 40%), in particular fertilizer of 10: 34: 0 and 11: 37: 0, which is saturated with ammonia superfosfornoy acid. These basic fertilizers used to produce triple HCS different composition by adding a urea or ammonium nitrate and potassium chloride.