UAN-28
Urea-ammonia nitrogen solution
pour into a container
EXW/FCA Khatsky
The goods can be delivered on the terms of self-pickup and / or can be delivered to any region of Ukraine by own road / rail transport.
TU U 20.1.36584168-002:2017
Appearance and color
Light yellow liquid, with a specific odor inherent in the components of the fertilizer
Density, g \ cm3, within
1.285
Alkalinity,%, within
0.21
Mass fraction of ammonium nitrate,%, within
40
Mass fraction of urea,%, within
30
Mass fraction of water,%, within
32-27
Mass fraction of total nitrogen,%, within
28
UAN-28
Urea-ammonium nitrate (UAN), or urea ammonia solution is a mixture of concentrated aqueous solutions of urea and ammonium nitrate mass fractions of which are 31-36 and 40-44% respectively. Sulfur (in the form of sulfates), phosphorus, potassium, microelements, humic acids, growth regulators of organic and inorganic origin can be added to separate brands of UAN. The industry produces three forms of this fertilizer: UAN-28, UAN-30 and UAN-32 with nitrogen content of 28, 30 and 32, respectively. Agrochemical company GROSSDORF also produces UAN with ‘floating formula’ and modified types of UAN. First of all UAN with sulfur (trademark ‘liquid fertilizers EuroUAN’).
In the composition of all brands of UAN nitrogen is in three forms: ammonium, nitrate and amide.
All these forms in this fertilizer are not volatile and do not cause nitrogen loss, so it can be applied superficially without wrapping in the soil. Nitrate and ammonia forms are directly available to plants. Initially, nitrate nitrogen is absorbed, which is very mobile in the soil. Ammonia nitrogen is retained in the soil and does not leach into deeper layers. When UAN is introduced into the soil, this form accumulates in the arable layer and becomes available to plants during the growing season. Part of the ammonia form is converted into nitrate. The amide form in the soil is transformed into ammonia, and later into nitrate. This nitrogen uptake system makes UAN a fast and prolonged fertilizer. Thus, UAN provides prolonged nutrition of plants with nitrogen. Due to the lack of free ammonia in the UAN, it does not evaporate into the atmosphere during application, but the presence of ammonium form makes it desirable to minimize wrapping, especially in conditions of high temperatures and no precipitation after application.
By the way, the density of UAN can be checked by a simple device with a hydrometer (by measuring the density of sulfuric acid solution in batteries), and their quality must be assessed by standardized methods in special agrochemical laboratories, which can accurately determine the content of ammonium, nitrate and amide, nitrogen. For example, UAN-28 contains NO3 –7%, NH4 + –7%, NH2 –14%. 100 kg of UAN-28 occupies a volume of 78 dm3 and contains 28 kg of nitrogen; 100 dm3 UAN-28 fertilizer contains 35.8 kg of nitrogen and weighs 128 kg.
Agrochemical advantages of UAN over other nitrogen fertilizers are due to the presence in their composition of all three forms of nitrogen:
nitrate nitrogen provides instant action;
ammonium nitrogen has a longer effect;
Both forms are assimilated by the leaves and root system.
amide nitrogen has the most prolonged effect and can be quickly absorbed by the leaves.
The amide form of nitrogen (NH2) easily penetrates the plant through the leaf surface (foliar). It needs more time to penetrate the root, because it must first turn into ammonium and then into nitrate, which are well absorbed by the root system. This process is limited by the presence of urobacteria in the soil and temperature. The rate of uptake by plants of amide, ammonium and nitrate forms of nitrogen depends on soil temperature.
Each substance and mixtures of different substances have their own physical and chemical properties. UAN is no exception in this respect. Physico-chemical properties of which are given in (table 4). Physico-chemical properties of this fertilizer allow to store it throughout the year.
The crystallization temperature of UAN-32 is 0 ° С, while UAN-30 is -9 ° С, UAN-28 is -17 ° С. in weather it is better to apply UAN-28. Low crystallization temperature minus 2 ° С and freezing minus 26 ° С allows to transport and store UAN all year round.