Department of Revenue Use of Soil Survey Fact Sheet
Department of Revenue Use of Soil Survey for Agricultural Land Evaluation
The Montana Department of Revenue (DOR) has been working
closely with the Natural Resources Conservation Service (NRCS) for several years
to effectively incorporate soil survey information into the upcoming reappraisal
of agricultural land in Montana. A statewide reappraisal has not been done for
The near completeness of Montana’s soil inventory and the use
in Montana of a statewide crop yield model for small grains greatly facilitated
consideration of using soils data as a foundation for this mandated DOR
The DOR agricultural land reappraisal is in the final stages,
with maps and DOR-generated productivity values recently being mailed to
producers/landowners. The productivity values they will be receiving are for
irrigated crops (alfalfa hay based), dry land crops (spring wheat based), animal
unit month (AUM) data for grazing lands (component range production based), and
forestlands (University of Montana Model used). The productivity values are
based on map unit weighted averages, considering all contributing soil
It is very important to note that yield data used from the
NRCS certified soils data is not used verbatim but is significantly
post-modified in the process of estimating productivity for land evaluation. One
reason for this is to obtain regional pertinence and balance in the context of
countywide yield averages as well as the use of proxy values where the certified
soils data is lacking (primarily irrigated yields and areas of Denied Access).
As a result, the productivity values on the DOR-provided production maps will
not match the NRCS certified soils yield data. They may be lower or higher
depending on several variables in DOR’s process.
The agreement and associated process established between the
NRCS State Soil Scientist and the DOR for addressing landowner queries as to
productivity is as follows: The county assessor will gather information provided
by landowners relative to yields being low (not likely an issue) or high for a
particular agricultural land use (irrigated cropland, dry cropland, or grazing).
This information is entered into DOR’s computer system and aggregated for
analysis at the county level and broader. Based on how widespread or local the
identified productivity anomalies end up being, after viewing all issues in a
broad geographic context, the DOR has the option of tweaking their
post-processing of the NRCS data or providing NRCS Soils Staff a list of map
units for NRCS to investigate.
NRCS Resource Soil Scientists or Field Office Staff who are
approached with DOR-provided soil productivity issues relative to their
reappraisal process are to refer them to the appropriate DOR county assessor.
This will ensure that the productivity issues work their way properly through
the system, and any needed adjustments are made appropriately, whether to the
DOR application of the NRCS Certified Soil Data or investigated on a map unit
basis by NRCS Soils Staff.
If you encounter any problems with the files provided on
this page, please contact
Webmaster at 406-587-6945.
This fact sheet is also available in Acrobat Reader format.
Department of Revenue Use of Soil Survey for
Agricultural Land Evaluation (PDF; 57 KB)