KAS urea-ammonia mixture, Odessa region.

KAS is a mixture of aqueous solutions of ammonium nitrate and urea (in the ratio of 35.4% urea, 44.3% saltpeter, 19.4% water, 0.5% ammonia water). The density of liquidfertilizer is up to 1.34 kg/m3.
This is the only nitrogen fertilizer that contains three forms of nitrogen:
nitrate - provides an instant effect,
ammonium - in the process of nitrification, it turns into nitrate form,(//tractor-service.com)
amide - as a result of the activity of soil microorganisms, it turns into the ammonium form, and then into the nitrate form.
Thus, KAS provides prolonged nutrition of plants with nitrogen. Due to the absence of free ammonia in the composition of KAS, it does not evaporate into the atmosphere during application, however, the presence of the ammonium form makes minimal wrapping desirable, especially in conditions of high temperatures and the absence of precipitation after application.
We also have other formulas: KAS 30+1S
KAS 26+4S+Zn, this formula is the most popular among farmers. On gray-deficient soils and crops with an increased need for sulfur-containing compounds, KAS 26 + S shows better results than more concentrated mononitrogen fertilizers.