THE FLORIDA STATE UNIVERSITY ARTS AND SCIENCES ...

APPENDIX B
CONVERSION SHEET FOR DENITRIFICATION RATE
As with the different methods used to compute the denitrification rate there are several
units in which the denitrification rate is reported. Heinen (2006) gave a brief description
of the various units and described four different units. The conversion from each of these
units needs to be done with care as the units are dependent on the methodology used.
With the conversion from point scale to field scale we must accept certain factors and
assumptions as outlined below.
The results may not always be justifiable but with the paucity of data on the
denitrification rate it is difficult not to accept the inherent errors that may be introduced
in these conversions. The outlined here conversions here are basic, but they are
mentioned in detail so that the underlying assumptions can be fully understood.
Most literature will often report the bulk density (ρ) and soil depth (d), it is by using these
two factors and other reported factors that we can convert between the reported units.
mg N
L
−1
−1
d
: Refers to the loss of nitrogen from a soil solution where L refers to the
volume of soil solution.
−3 −1
g N m d : Refers to the loss of nitrogen on a soil volume basis.
−1 −1
g N kg d : Refers to the loss of nitrogen on a dry soil weight basis
−1 −1
kg N ha d : Refers to denitrification in a certain layer. In such cases the user must
report the depth of the layer.
As an example of the variation in units, the dataset provided by Dr Oehler has
denitrification reported in units of
reported on a dry soil weight basis but differs from
−1 −1
mg N kg d this is the same as denitrification
174
−1 −1
3
g N kg d only by a factor of 10 .