Principles of application
Anhydrous ammonia can be applied with the help of equipment team and special designed aggregates. Fertilizer application is to be made in autumn.
To prevent ammonia losses, fertilizer is to be applied to the depth not less than 12-15 cm with the ground temperature at least 20 degrees. High temperatures cause enforcement of nitrification and denitrification processes that is why nitrogen can be washed into the ground or released in the air. Depth of fertilizer application should be extended to18-20 cm on light, weakly structured and dry soils. It is not advisable to apply anhydrous ammonia on water-logged soil that can lead to nitrogen losses and soil repacking under wheels of large tractors and aggregates. On limed soils or soils with high calcium content the depth of fertilizer application should be 3-5 cm deeper. Anhydrous ammonia that has been applied into the soil causes temporary toxic effect on plants’ root system and soil biota which resumes after ammonia full conversion to ammonium or nitrate. The level of ammonia fixation in soils and its losses are correlated with a row width. In case of the row width reducing, nitrogen fixation in soil increases and nitrogen costs decrease.
Extension of the row width leads to increasing of ammonia concentration that maximizes losses because of nitrogen vapor pressure building up. Ammonia application alkalizes the soil and then acidifies due to partial conversion of ammonia form to nitrogen, soil solution reaction returns to its initial indices that were before ammonia application.
During anhydrous ammonia application, it is easy to find out possible losses of nitrogen with the help of one easy method: there is absence of ammonia smell at 1-2 m distance from aggregate.
Regular anhydrous ammonia application at high doses can lead to severe decreasing of soil fertility due to declining of soil biota abundances.