As we move toward fall fertilization and planning for spring, the question of Nitrogen (N) Stabilizers comes up.  Can we apply a material with our N fertilizer to protect it from loss? 

Nitrogen in the form of urea can be lost thru ammonia volatilization when surface applied.  Eventually all forms of nitrogen will convert to nitrate and are subject to leaching or denitrification losses. To obtain a bigger bang for your applied N buck, different N materials and nitrogen additives may be used but timing and placement is the key.  Nitrogen materials applied in the fall should be delayed until after soil temperatures are below 50 degrees. As of October 9th, soil temperatures at the 4 inch depth were still ranging from 57 to 68 degrees. In addition, N should be either incorporated with tillage, or, with no-till, should be injected into the soil.  If this is not possible or practical, N applications should be delayed until late winter or early spring (no snow cover) when conditions (cool and moist) do not favor ammonia volatilization.  If surface N applications need to be made later in the spring, a urease inhibitor should be considered with the application.  For coarse textured soils in eastern South Dakota and medium textured soils in SE SD which have a full profile of water, the grower should consider use of a nitrification inhibitor with spring N applications. 

Effective nitrogen stabilizers or additives (urease and nitrification inhibitors) are discussed in a new NDSU publication “Nitrogen Extenders and Additives for field crops”.  The pamphlet’s author is Dave Franzen from NDSU and it was reviewed by other extension soil specialists from the North Central Region.