Fertilizers are used by agricultural producers to optimize the nutrition of farmed crops. Crops, replenishment of elements taken out with a crop (alienation from soil), and also for increase of soil fertility. At present, there is a relative variety of fertilizers on the market. All of them are divided into two large groups: mineral and organic.
In turn, mineral fertilizers are divided into types: simple and complex, and also distinguish types of fertilizers – Solid and liquid. Simple mineral fertilizers are used to replenish in the soil of one element of food (for example, nitrogen, phosphorus or potassium). From liquid mineral fertilizers to simple fertilizers include anhydrous ammonia, ammonia water and UAN. All of them contain only one battery in their composition – nitrogen. UAN is a mixture of aqueous solutions of ammonium nitrate and carbamide (in the ratio of 35.4% of carbamide, 44.3% of saltpeter, 19.4% of water, 0.5% of ammonia water). Density of liquid fertilizer to 1.34 kg / m3. This is the only nitrogen fertilizer that contains three forms of nitrogen:
Nitrate nitrogen (NO3-) - provides instantaneous action. The nitrate form is quickly and completely absorbed by the root system of plants (it passes into the soil solution);
ammonium nitrogen (NH4 +) – Is bound by the solid phase of the soil (contained in the soil-absorbing complex) and is absorbed by the root system;
Amide nitrogen (NH2 +) - as a result of the activity of soil microorganisms it turns into an ammonium form, and then into a nitrate form. The amide form of nitrogen easily penetrates the plant through the leaf device, but it will take considerably longer to penetrate the plant through the root.
UAN is a nitrogen fertilizer that is effective in cereal crops and in the cultivation of succulent fodder. Its application positively affects the increase in the yield of cereals and the intensive growth of green mass. As a rule, it is not used on potatoes and vegetable crops. On potatoes entering the UAN will ensure the formation of a powerful aboveground part of plants, the tubers are formed small, besides they are Will not be stored for a long time.
Vegetable crops should use complex fertilizers, which contain not only nitrogen, but also phosphorus, potassium, magnesium, as well as all trace elements. It is very important that the ratio of the main macroelements is introduced and for different cultures it can be significantly different.
Ammonium nitrate and urea have spread from simple nitrogenous solid mineral fertilizers on chernozem and chestnut soils.
However, these shortcomings are easily eliminated. Special conditions for the transportation of UAN are required, which are limited by the transshipment of vehicles (due to the high density of the UAN). Therefore, it is recommended to fill the capacity by no more than 80%. The presence of anticorrosive additives reduces the corrosion of carbon steels almost to zero.
The norms and doses of UAN application depend on the type of culture, the time and method of introduction, the predecessor and other factors. There are no special restrictions.
The first spring top feeding of winter crops is carried out after the snow falls when the vegetation of plants is resumed, during tillering with a dose of 30-40 kg ai. (Active ingredient) per hectare, when the temperature is not higher than 10° C, no dilution of the UAN is required. Perhaps an increase in the rate of fertilization, depending on the physiological state of plants.
The second top feeding is done in combination with the addition of plant protection products, growth regulators in the phase of the beginning of the outlet into the tube, while the single nitrogen norm should not exceed 30 kg ai. In the second feeding of UAN, in order to avoid burns, it is advisable to dilute with water in a ratio of 1: 2, and when combined with a herbicide 1: 3 or 1: 4. If it is necessary to introduce additional nitrogen, a third late fertilizing is possible in the phase of the beginning of the winter wheat ear with a norm not exceeding 10 kg ai.
When applying UAN for fertilizing on vegetating plants, the dose of nitrogen should not exceed 10-20 kg ai. With compulsory dilution with water in a ratio of 1: 4 due to possible burns of plants.
For UAN barley, it is most expedient to make it as the main fertilizer for pre-sowing cultivation.
UAN solutions can be made by diluting and not diluting with water. It depends on the technical capabilities of the units. When diluting, the working solution consumption per 1 hectare should be 100-300 liters.
The best time for foliar top feeding with UAN solutions is morning (in the absence of dew) and evening hours. In the cool and cloudy weather, this work can be done during the day. Do not feed plants with UAN solutions at temperatures above 20 ° C, low relative air humidity, on a sunny day, as in these UANes, burns of the leaf surface of plants are possible. The young leaves of plants are most prone to burns. In all phases of plant development, UAN solutions even with a dose of 10 kg nitrogen per 1 ha can cause some plant burns, but they do not lead to a decrease in yield.
When using UAN as a foliar top feeding, the pH of the solution should be in the range of 8-9. The effectiveness of this fertilizer depends largely on weather conditions. It is maximal when the solution remains on the leaf surface for a long time. Therefore, highly effective crop treatment is achieved in cloudy, cool weather.
Immediately after heavy rains, strong dew, it is not recommended to apply UAN in the mixture, since the sediments make the structure of the upper leaf of the leaf more permeable (respectively more sensitive), so the spraying of the crops should be carried out after the leaves of the plants dry.
The optimal time of day for the application of UAN in a mixture with herbicides is an evening time, as the absorption of nitrogen at night is slower. When applying UAN, it is necessary to use sprayers with a droplet size twice as large as herbicides.
- Replace parts from non-ferrous metals with PVC, stainless, or fiberglass;
- To carry out foliar top feeding, replace the spray nozzles of sprayers with deflectors.
The size of the drops sprayed with sprayers when applying plant protection products (herbicides, fungicides) does not exceed 0.3 mm. This is done to ensure that the drops fall on pests and stay on the leaves, thereby protecting them from phytophages.
But with the feeding of UAN, you need to achieve this size drop, so that the substance slides off the plant, just moistening the leaf. Otherwise, it may get burnt. And the deflector nozzles just give the needed large-droplet solution. Slot nozzles can only be used when applied with herbicides, with mandatory dilution of UAN with water. To work in windy weather, use extension hoses.
Compare UAN with HCS or granulated complex fertilizers, it's like comparing the nutritional value and kilocalories in the second dish and tea.
Complex fertilizers include mineral fertilizers containing two or more nutrients. They are divided in composition: double (nitrogen-phosphorus, NP; nitrogen-potassium, NK; phosphoric-potassium, PK); and triple (nitrogen-phosphorus-potassium, NPK). The assortment of complex fertilizers is mainly represented by the following forms: double nitrogen-phosphorus fertilizers - ammophos, nitroammophos and nitrophosphates and double phosphate-potassium fertilizers - potassium phosphates, triple complex fertilizers - ammophoska, nitroammophoska and nitrophoska, magnesium-ammonium phosphate.
According to the method of production, complex fertilizers are divided into complex, complex-mixed (combined) and mixed fertilizers. To complex fertilizers of industrial production include such fertilizers as potassium nitrate, ammophos, diammophos. They are obtained by chemical interaction of the initial components. In the complex solid and liquid fertilizers in the process of their production can be introduced and trace elements, as well as herbicides and pesticides.
Complex or mixed fertilizers include complex fertilizers obtained in a single technological process and containing in one granule two or three basic plant nutrients, although in the form of various chemical compounds. They are produced by special chemical and physical treatment of primary raw materials or various one- and two-component fertilizers. These include: nitrophos and nitrofosca, nitroammophos and nitroammophoska, ammonium and potassium polyphosphates, carboammophos, phosphate-potassium pressed fertilizers, liquid complex fertilizers. The ratio between the nutrients in these fertilizers is determined by the amount of the raw materials when they are obtained.
Mixed fertilizers are mixtures of simple fertilizers obtained in the factory or on fertilizer plants at fertilizer application sites by dry mixing.
Complex and complex-mixed fertilizers are characterized by a high concentration of nutrients, so the use of such fertilizers provides a significant reduction in the costs of the farming for their transportation, mixing, storage and application.
Among the shortcomings of complex fertilizers is that the proportions in the content of NPK in them vary within a narrow range. Therefore, when introducing, for example, the necessary amount of nitrogen, other nutrients, less or more is added than required.
In a small amount, multifunctional fertilizers are used that contain, in addition to the main nutrients, microelements and biostimulators, which have a specific effect on soil and plants.
In recent years, the production of fertilizer mixtures began to develop in Russia. Fertilizer blend – this is a mechanically mixed, compatible with each other types of fertilizers. Combining their composition, you can choose the best option for any crops and regions. The use of fertilizer mixtures has long been common in countries with developed agriculture.
Ammophos (monoammonium phosphate, MAP, NH4H2PO4) - is a highly concentrated granular nitrogen-phosphorus fertilizer, the nitrogen in which is represented by the ammonium form. The product is non-hygroscopic, does not dust and does not cake. It has an even particle size distribution and is readily soluble in water. On the basis of ammophos, any brands of mixed fertilizers are prepared. Ammophos is a universal highly effective fertilizer used on all types of soils for basic and sowing application for all crops. It is used in conditions of protected soil. It is advisable to use the product in arid zones, where nitrogen fertilizers are required much less than phosphorus fertilizers.
Sulfoammophos ((NH4) 2HPO4 + (NH4) 2SO4) - is a universal water-soluble granular complex nitrogen-phosphorus fertilizer. The product is not caked, non-hygroscopic, has an even particle size distribution, does not dust. It has a better solubility of phosphorus than the ammophos and a ratio of nitrogen and phosphorus. Nitrogen in sulfoammophos is presented in ammonium form, due to which it weakly flushes out of the soil and promotes more intensive absorption of phosphate ions by plant roots. The composition of this fertilizer includes sulfur, which contributes to an increase in the percentage of gluten in wheat, the content of oil in sunflower, soybean and rapeseed. Also, the fertilizer contains calcium and magnesium (0.5% each) - important elements for the life of plants.
Sulphoammophos is used on all types of soils and for all crops. This product is used for basic, sowing application, as well as for fertilizing plants. Can be used in conditions of protected soil along with nitrogen and potassium fertilizers. On its basis, any mixed fertilizers are prepared. In Russia, the only producer of this fertilizer is the MHC «Eurochem».
Diammonium phosphate (diammonium hydrogenphosphate) (NH4) 2HPO4 is a concentrated, non-nitrate, water-soluble, granular nitrogen-phosphorus fertilizer. Not hygroscopic, does not cake, has an even particle size distribution, does not dust.
Ammophoska (NPK) is a highly effective complex fertilizer containing three nutrient components: nitrogen, phosphorus and potassium. It is a complex multicomponent system in which phosphorus and potassium are represented mainly by phosphates and potassium sulfate, nitrogen - ammonium sulfate. The product is non-hygroscopic and does not cake. Nitrogen is represented in ammonium form, due to which it weakly flushes out of the soil and promotes more intensive absorption of phosphate ions by plant roots. The composition of this fertilizer includes sulfur, which contributes to an increase in the percentage of gluten in wheat, the content of oil in sunflower, soybean and rapeseed. In some UANes fertilizer contains calcium and magnesium (0.5% each). Chlorine free ammophoska is a good fertilizer for saline soils. Ammofosca is introduced as the main and pre-sowing fertilizer on all types of soils under all crops (chlorine is especially preferable for chlorine sensitive crops, vegetables, potatoes, vineyards, tobacco, which allows to improve the quality of products and increase the shelf life). Can be used in protected soil.
Nitroammophos and nitroammophoska are obtained by neutralizing ammonia with mixtures of nitric and phosphoric acids. Fertilizer obtained on the basis of monoammonium phosphate is called nitroammophos, with the introduction of potassium - nitroammophos. These complex fertilizers are characterized by a higher content of nutrients than nitrophoska, and when they are obtained, there is a wide opportunity for changing the relationships between N, P and K in their composition. Nitroammophoses can be produced with a content of N 30-10% and P2O5 of 27-14%. In nitroammophoska, the total nutrient content (N, P and K) is 51% (in grades <A> 17-17-17 and <B> - 13-19-19). Other brands are also produced. Nutrients, not only nitrogen and potassium, but also phosphorus, are contained in water-soluble form and are readily available to plants. The effectiveness of nitroammophosca is the same as that of simple water-soluble fertilizers.
Liquid complex fertilizers (LCF) are obtained by neutralizing ortho- and polyphosphoric acids with ammonia with the addition of nitrogen-containing solutions (urea, ammonium nitrate) and potassium chloride or sulphate, and in some UANes also salts of microelements. The total content of nutrients in liquid complex fertilizers based on orthophosphoric (extraction or thermal) acid is relatively low (24-30%), since in more concentrated solutions at low temperatures the salts crystallize and precipitate. The ratio of nitrogen, phosphorus and potassium in the LCF can be different, the content of N-5- 10%, P2O5-5-H and K2O-6-10%. In our country is produced mainly LCF with a nutrient ratio of 9: 9: 9, and also with a different ratio (7: 14: 7, 6: 18: 6, 8: 24: 0, etc.).
On the basis of polyphosphoric acids, HCB with a higher total nutrient content (more than 40%), in particular, 10: 34: 0 and 11: 37: 0 fertilizers, are obtained by saturation of superphosphoric acid with ammonia. These basic fertilizers are used to produce triple LCF of various compositions, adding urea or ammonium nitrate and potassium chloride to them.
When using liquid complex fertilizers, a complex of special equipment is required for their transportation, storage and introduction. They can be applied in the same ways as solid ones: by continuous distribution on the soil surface before plowing, cultivation and harrowing, during sowing, as well as in fertilizing - when inter-row cultivation is tilled or superficially on cultures of continuous sowing.
LCF 10:34 – This is a highly effective nitrogen-phosphorus fertilizer of grade 10:34 (10% - ammonium nitrogen and 34% of completely assimilated total phosphates).
Liquid fertilizers are free from the drawbacks inherent in solid fertilizers. They have free flowing, do not dust, do not crochet, damp weather, and rain do not have any influence on them. The cost of the operation for storing, entering the soil and loading during transportation of the liquid fertilizer is lower than that of solid fodder.
The quality of HP NP 10:34 meets the requirements of technical specifications (TU 113-08414-91):
Safety requirements: The HVAC is fire-safe explosive-safe.
Transportation, storage: LCF does not contain free ammonia, so they can be stored and transported in not sealed containers. The product is not flammable, not explosive, not toxic. Practically does not corrode ferrous metals due to the formation of a phosphate film on their surface. Transported in tanks in accordance with the rules for the carriage of goods operating on this mode of transport.
Fertilizer liquid complex (LCF) is an aqueous solution of ammonium phosphate, contains two nutrient elements: nitrogen and phosphorus in the ratio of 11:37. Phosphorus in LCF is present in the form of ortho- and polyphosphates, in a fully digestible form. Liquid complex fertilizer is a transparent, greenish-bluish liquid that practically does not contain insoluble residues, suspensions.
Liquid complex fertilizers (11-37) – This is a highly effective, high-speed fertilizer. In addition to condensed phosphates (70-80% of the total mass of P2O5) and nitrogen, the LCF contains sulfur and magnesium. All nutrients are in solution, so they are easily accessible to plants.
Liquid complex fertilizers have high efficiency in crops of any crops, in all regions, especially on carbonate soils.
Utilization of LCF has undoubted advantages over solid fats: a high uniformity of nutrient input is introduced, their losses are reduced, and working conditions are improved. Feeding with solutions of LCF can be combined with soil treatment with microelements, plant protection products. They should be used in the same way as solid fertilizers: by continuous distribution on the soil surface before plowing and cultivation, locally during sowing, and also for feeding crops. The liquid fertilizers are used for encapsulation and seed dredging, and their presowing treatment.
Fertilizer does not contain harmful impurities and fully meets the increased environmental requirements.
Thus, all produced mineral fertilizers have their specific purpose, as well as properties, terms and methods of application. Depending on what elements of nutrition need to be introduced into the soil or what the plants need, UAN, granular fertilizers or LCF are used.