Nikolay Shestakov, NIIK Russia, review a variety of methods used for the production of UAN.
The acqueos solution of urea and ammonium nitrate (UAN) is a unique nitrogen fertilizer, providing an efficient and reliable source of nitrogen in nitrate, ammonium and amide forms. nitrates enter the plant through the roots, providing quick access to nutrients and adequate nutrition to promote normal development. Ammonium, on the other hand, is not absorbed by the plant and is stored in the soil, where it is converted into nitrates by bacteria acting in the soil under relevant temperature and moisture conditions. It is not easy washed out of the soil. Meanwhile, amide nitrogen enters the plant through its leaves. In order to penetrate through roots, this form must first turn into ammonium and consequently, into nitrates. for this reason, the UAN fertilizer is considered as slow acting fertilizer with a long action period.
When applying UAN, nitrogen losses do not typically exceed 10% of total nitrogen, while other applied granular nitrogen fertilizers usually show 30-40% nitrogen loss.
The technical article was first published in WorldFertilizer September 2020