Urea-ammonium nitrate, UAN fertilizer can be applied to all crops, but most expediently — under grain crops as a main fertilizer or as foliar feeding.
In industrial conditions, as a result of its more uniform application to the soil, the efficiency of UAN fertilization compared to solid nitrogen fertilizers is much higher.
When using UAN fertilizer for foliar feeding, the pH of the solution should be in the range of 8-9. The effectiveness of this fertilizer depends largely on weather conditions. The maximum effect is get when the solution remains on the surface of the leaf for a long time. Therefore, the best results of foliar feeding are in cloudy and cool weather.
Spraying plants with UAN fertilizer can cause the appearance of necrotic spots on the leaves or tissue damage. The degree of damage to the leaves depends on the culture, the phase of its development, the fertilizer dose and, especially, the weather. Application of liquid fertilizer UAN on winter crops at the beginning of early spring regrowth (first feeding), when the air temperature does not exceed 5-10 C, is not dangerous for plants even at a dose of 80-100 kg/ha. When applying fertilizer UAN on winter crops at the beginning of vegetation (the first fertilizing), when the temperature is not higher than 10C, no fertilizer dilution is required.
When carrying out the second feeding in the phase of the beginning or middle of the tubing of the plant, when the temperature is 16-18 C and above, the fertilizer dose should not exceed 20-30 kg/ha.
The use of doses of N40 or more in such conditions, especially in sunny weather, causes leaf burns and a decrease in crop yields. Therefore, with the second fertilizing of winter fertilizer UAN in order to avoid burns, it is advisable to dilute the mixture with water in a ratio of 1: 2.
The terms of fertilizer application for winter period are the same as the time of treatment with herbicides, fungicides. Therefore, the introduction of liquid nitrogen fertilizer UAN is easy to combine with plant protection products against weeds and diseases.
The introduction of liquid fertilizers of UAN at a dose of N20-30 together with butyl ether 2.4 D (the norm for the preparation of 1.2 kg/ha) in the phase of tillering or the beginning of tubing gives the same effect as the separate application of these agents , but the economic effect is much higher with combined (joint) use due to the reduction of energy costs and manpower. When applying fertilizer UAN on crops of winter crops together with the herbicide, the fertilizer must be diluted with water in a ratio of 1: 3.
A good economic effect is provided by a combined application for winter fertilizers of UAN and retardants. Studies show that when cultivating winter crops under conditions of intensive technology, the combined application of solutions of UAN with retardants, fungicides and herbicides is economically beneficial, since it reduces energy inputs and labor resources by reducing operations during the introduction. It should be noted that in the winter wheat crops, the economic efficiency of joint application of liquid mineral fertilizers of UAN, retardants and fungicides is much higher than in winter rye.
Liquid mineral fertilizers UAN with retardants on winter crops are recommended to make in the period of the beginning and the middle of tubing of plants. When the UAN is applied together with retardants at the beginning of the tubing, the dose of nitrogen should not exceed 40 kg/ha with later top feeding (middle tubing) — 20-30 kg/ha before earning — not more than 10-15 kg/ha. This is due to the fact that in a later period when the air temperature is above 18 C there is a danger of burning of the upper leaves, which take an active part in the formation of assimilants.
Effective application of UAN on winter crops together with fungicides, in particular with bayleton and foundation. The dose of fungicides mixed with UAN — 0.5-0.6 kg/ha. When co-application of UAN with retardants and fungicides is also necessary dilution of the mixture with water depending on the air temperature in the ratio 1:2 – 1:3.
Application of UAN separately or together with retardants, herbicides and fungicides on winter crops should be planned, proceeding from the possibility and conditions for each farm. The following schemes for using UAN and mixtures with other chemicals are possible:
1. The usual dose of UAN fertilizer for winter and spring crops is determined depending on the state of crops, soil fertility, predecessor, planned crop; in the second feeding the dose is adjusted taking into account the results of soil and plant diagnostics.
2. Early spring feeding with winter nitrogen after wintering. Top feeding UAN should be carried out primarily in crops where increased tillering is required. The dose of nitrogen in the first top feeding is determined depending on the condition of winter crops, soil fertility and predecessor. On crops with a density of plants 200-300 pcs. On 1 square m. nitrogen dose – 80 — 50 kg/ha, on more dense (300-350 plants per 1 sq. M.) - 50-40 kg/ha.
3. A mixture of fertilizer UAN and fundosol on winter crops is used in the spring at the beginning of the plant's release into the tube when root rot spreads and there are signs of powdery mildew. The dose of UAN is determined depending on the needs of the plants, not more than 40 kg/ha, fondosol — 0.5 kg/ha.
4. A mixture of UAN fertilizer with retardants can be used at the beginning of the fase of tubing. Nitrogen dose 30-40 kg/ha, retardant TUR — 3.5-4 kg/ha, Campozane — 3-3.5 l/ha. The mixture must be used on winter wheat. On winter rye UAN and camphor are more effective.
5. A mixture of fertilizer UAN with retardants and fungicides is used in the middle of tubing. Nitrogen dose 20-30 kg/ha, TUR — 3,5-4 kg/ha, campozane -3-3.5 byletona — 0.5 kg/ha. Working mixtures of UAN, retardants and fungicides must be prepared immediately before application.
6. Under UAN barley, it is most advisable to make it as the main fertilizer. If a foliar application is required, the dose of UAN should not exceed 15-20 kg/ha, since higher doses cause burns of plants. UAN must be diluted with water in the ratio 1: 1.5-2 before application.
Usage of UAN in undiluted form for feeding barley in the phase of the beginning of tubing in a dose of N30 leads to a decrease in the grain yield by 4- 4.5 q/ha. When applying the same dose of UAN together with tilt, the yield decreases by 5.2, in a mixture of UAN + tilt + Cu — At 5-8 c/ha. Thus, the application of UAN fertilizer to top feeding of spring crops in the tillering end phase — Tubing and in a mixture with fungicides and micronutrients in undiluted form is not recommended.
Working fluid consumption (UAN, retardant and fungicide) — 250-350 l/ha, depending on the dose of nitrogen. The economic efficiency of the joint use of UAN and other chemical means in experiments with winter wheat and rye in the cultivation of winter cereals by intensive technology is higher than when separately used. The main reason for this — Reduction in the cost of application and uniform distribution of fertilizer by area.
1.When applying fertilizers, you must constantly monitor the width of the sprayer. It must correspond to the technological track. It is unacceptable to have untreated strips at the joints of two adjacent passes, and also double treatment of plants, as this can cause burns of plants.
2. Strictly adhere to the operating mode of the spraying system: do not allow pressure drop, change the height of the spray. Sprayers should be constantly checked for flow and uniformity of spray, which is achieved by maintaining constant pressure in the system (at least 0.4 MPa) and selecting the same sprayers. At doses of UAN up to 150 l/ha, ordinary centrifugal nozzles with a diameter of 1.2 mm are used, with a large dose of — 2.5 mm.
3. Do not apply liquid fertilizer UAN, growth regulators and fungicides in rainy weather.
4. When preparing tank mixtures should strictly maintain the recommended dose of nitrogen UAN, growth regulators and fungicides. The components must be mixed well.
5.To achieve greater uniformity of the treatment of plants during the installation of sprayers, it is necessary to provide for the possibility of adjusting the rotation of the nozzles. The number and distance between them are set in such a way as to ensure uniformity over the entire width of the grip.
When preparing solutions on farms, water should be heated in special heaters up to 50-70°C, which greatly accelerates the dissolution of fertilizers.
UAN prefabricated solutions contain an inhibitor that prevents corrosion of carbon steel, so they can be transported in railway tanks, tank trucks (ARUP-8), semi-trailers — Cisterns (OZTP-9625, OZTP-9654) and in other containers used for transportation of liquid fertilizer. The time of loading and unloading operations is reduced 1.8-2 times compared to solid nitrogen fertilezes.
UAN fertilizer is stored in containers of thin-walled ordinary steel or in concrete storage. The physicochemical properties of fertilizers do not change for 8-12 months. There are practically no nitrogen losses.
Put the UAN into the soil and apply it as foliar fertilizing (spraying) using high-performance ground-based means — rod sprayers, aggregates intended for spraying herbicides (ПЖУ-5, ПЖУ-9, etc.), and also with the help of aviation. The most technologically and economically application of the UAN with the help of rod sprayers, which allow the fertilizer to be applied evenly and efficiently. It should be borne in mind that rubber products (gaskets in joints of hydraulic systems of machines) made of MBS-M-5 rubber, as well as connecting hoses with thread reinforcement after 1000 hours in a UAN environment at 30°C become brittle and unfit for work .
Calculation of the doses of UAN nitrogen before application should be made taking into account the fertilizer brand and its density. In the factory certificate for each brand of fertilizer UAN the percentage of nitrogen mass in percent (for fertilizer weight), density and other parameters is indicated. In production conditions, the dosage of UAN in the preparation of tank mixtures is advisable to carry out not by weight, but by the volume of the solution. To do this, before applying the fertilizer, you should calculate the nitrogen content in 100 liters of solution:
N — Amount of nitrogen in 100 liters of solution, kg;
D — Density of solution;
G — Grade of nitrogen (number means the content of 100 kg of nitrogen solution, kg).
When small doses of nitrogen are applied with UAN sprayers or a mixture of UAN solution with retardants or fungicides, it is also necessary to dilute with water by a factor of 1.5-2.
All work with UAN and working mixtures of UAN with retardants and fungicides (preparation of UAN, transportation of UAN, introduction of UAN) must be carried out in accordance with the Sanitary Rules for the storage, transportation and use of mineral fertilizers in agriculture of the Ministry of Health of Ukraine.
Before starting work, it is necessary to check and, if necessary, thoroughly clean and rinse the tanks, pipelines, cranes and other elements of the units. Cleaning the cranes is only permitted when the engine of the machine is completely stopped. After using the machines and units, you should also clean and rinse the containers and hoses.
Persons who are acquainted with the rules of operation and maintenance of aggregates who have studied safety techniques when working with liquid fertilizers and pesticides are allowed to work in warehouses when preparing, transporting UAN and introducing UAN.
The UAN price is determined by market seasonal demand. Therefore, to buy UAN at a lower price is possible in the off-season.