LaMotte STH Outfit - Manual (Page 17)

17
Ammonia Nitrogen
A fertile soil may be expected to give a low ammonia nitrogen test reading,
unless there has been a recent application of nitrogenous fertilizer in
forms other than the nitrate. The rapid disappearance of ammonia after
fertilizer application indicates the desired transformation of the ammonia
to the more available nitrate compounds. In forest soils ammonia is the
most abundant available form of nitrogen. If there is a satisfactory rate
of nitrogen transformation, the humus layers of a forest soil will produce
very high concentrations of ammonia nitrogen.
PROCEDURE
1. Use a transfer pipet (0364) to transfer four drops of the general soil
extract to one of the larger depressions on a spot plate (0159).
2. Add one drop of *Ammonia Nitrogen Test Solution (5103PS). Stir
with a clean stirring rod (0519). Allow to stand for one minute.
3. Compare the resulting color against the Ammonia Nitrogen Color
Chart (1302). The test result is expressed in relative values of
ammonia nitrogen from very low to very high. For approximate
corresponding values in parts per million or pounds per acre, see
page 19.