Soil Testing Program

Value Added Fertility Products

Specialty Liquid Fertilizer


Value Added Fertility Products


Ammonia based fertilizers, including Urea (46%) and UAN (28-32%), have the propensity to volatilize or gas off when favorable soil and environmental conditions exist.  Research indicates that as much as 90% loss of these products can occur within a few days of a surface application.  However, 30 to 50% loss is more realistic in our geography.  Please see the attached link for more specific information on how ammonia hydrolysis and the Urease processes works.

Ammonia Volatilization 

Ammonia Volatilization Demonstration.pptx


A second method of nitrogen loss is from Denitrification and/or Leaching from the soil.  Denitrification occurs when soils are waterlogged for more than a few days and happens more readily when soil temps are above 55 degrees.  Please see attached link for more information.


Nitrification Inhibitors


Because Nitrate-N is very mobile in the soil, it has the tendency to move with soil water.  Leaching occurs when water moves through the soil profile driving down the Nitrate.  Depending on soil type and depth, this can move the Nitrate-N below the root zone rendering it unavailable to the crop.  However, as the soil profile begins to dry, capillary action can pull the Nitrate-N back closer to the soil surface.  This assumes that it was not leached into a subsurface water body or laterally into a stream or creek.  


GCA is proud to offer Treated Urea that greatly reduces ammonia volatilization.  Year over year, more nitrogen is lost due to ammonia volatiliztion than from leaching and/or denitrification.  That is why we have chosen to use Anvol as our Urease Inhibitor for most applications.  If leaching and/or denitrification is of primary concern, we would recommend using Super U from Koch.

  • NBPT is the most widely used and trusted Urease Inhibitor.  NBPT delays the Urease enzyme and typically provides 7-14 day of protection.
  • DCD reduces the Denitrification and Leaching loss and typically provides protection for 21 days.  DCD functions by delaying the Nitrification process in the soil.