Originally Posted by Skipster
Studies have shown over and over that soil N content is usually very stable in frozen soils.
In the fall, nitrates tend to move down in the soil profile with increased rainfall, then move up with the freeze/thaw of late fall, stay stable in mid-winter, then move up with spring freeze/thaw cycles, and back down with rain and snow melt. Nitrate really follows the water.
Denitrification reactions are inhibited by cold temperatures in fall/winter/spring, do very little nitrate is lost.
Ammonium tends to hang around on CE sites and very little is converted to nitrate in cold weather because the weather is too cold for amped activity of those microbes. This is partially the reason that anhydrous ammonia can be used as an ag fertilizer and is applied in the cooler weather.
Once you look at the dynamics of the living world, you better understand why applications are done in a particular manner.
That is interestting that N moves upwards through the soil profile after moving down for a while... back to that in a minute... right now I would like to discuss with you on the subject,,, snow...
make sense, that frozen ground would stabilize the elements within it... but my point is that one may have frozen ground in Nov.,,, but thawing completely under a foot of snow,,, by December... now,,, the snow melts underneath and soaks into the ground, going down, down, down, replenishing the water table over the course of the Winter...
Now your saying that 'because it is colder than Summer' that N no longer leaches down when it's under the snow, but actually rises to the surface???
You see,,, I've always assumed that because water is percolating downward through the soil,,, that N would leach downward along with the water, regardless of the temperature... That is incorrect???