A Model to Incorporate Soil Survey and Allotment Analysis 
Data into Range Management Planning 
JACK E. SCHMAUTZ 1 
Range allotment analyses and soil surveys 
have been completed on many livestock allot- 
ments on National Forest ranges in northeast- 
ern Washington, northern Idaho, Montana, 
North Dakota, and northeastern South Dakota. 
The maps and large amount of data that have 
been obtained from these analyses and surveys 
are quite confusing to most land managers. 
The problem is: How can this information be 
summarized and integrated into a usable work- 
ing tool for the resource manager? 
A model has been developed to incorporate 
soil survey and allotment analysis data into 
range management planning.? The basic infor- 
mation used in the model was obtained from a 
detailed soil survey * and from the range anal- 
ysis of the Cow Creek Allotment, Ashland 
Ranger District, Custer National Forest, 
southeastern Montana. 
The range allotment analysis was made ac- 
cording to current Forest Service regional 
standards.‘ Soils were mapped to the series 
level, and mapping units were based on slope, 
salinity, and erosion phases. 
THE MODEL—WHAT IT IS 
The model for the Cow Creek Allotment con- 
sists of: 
1. A base soils map on which the soil series 
have been classified into five productive poten- 
tial classes. 
2. Transparent overlays showing: 
a. Soils classified into four potential ero- 
sion hazard classes. 
b. The allotment classified according to 
(1) range condition class, (2) trend in condi- 
tion, and (3) primary and secondary range. 
38. A table in which the soils were rated as 
*The author is on the staff in the Division of Range 
and Wildlife Management, USDA, Forest Service, Mis- 
soula, Mont. 
* Developed jointly by Richlen, E. M., Division of 
Soils and Watershed Management, Region 1, USDA 
Forest Service, Missoula, Mont.; Almen, C. E., Colville 
National Forest, Colville, Wash.; Smith, H. O., Custer 
National Forest, Billings, Mont.; and the author. 
* Berg, A. B. Logan, L. D., and McConnell, R. C. 
Soil Management report, Ashland and Ft. Howes Ran- 
ger Districts, Custer National Forest, Billings, Mont., 
unpublished report on file at Billings, Mont., 112 pp., 
illus. 
* Allotment analysis instructions and standards and 
given in Forest Service Handbook 2209.21 R1, Range 
Environmental Analysis Handbook. 
to their probable response or suitability to de- 
sired cultural or management practices. 
STEPS IN MAKING THE MODEL 
1. Soils were classed into five productive po- 
tential classes. 
a. Clipping studies to estimate production 
potential were made on modal soils on ranges 
judged to be in good or excellent condition. 
These soils were grouped into five production 
classes, with the lowest class producing 400 
pounds or less of forage per acre and the high- 
est yielding 875 pounds or more. 
b. No ranges in good condition could be 
found for some soils. Productivity potentials of 
these soils were extrapolated from soils for 
which clipping data were available. Soils with 
similar physical and chemical characteristics 
were judged to have similar productive poten- 
tials and were classed accordingly. Physical 
characteristics considered were: Thickness, 
texture, structure, infiltration, and porosity. 
Chemical characteristics used were: Cation ex- 
change capacity, pH, base saturation, C:N ra- 
tios, and organic matter content. Data for 
these characteristics were obtained from the 
soil survey. 
ec. The productive potential classes were 
colored on a base soils map with a scale of 2 
inches for each mile. 
2. Soils were subjectively classified into 
four potential erosion hazard classes. 
a. Potential erosion hazard classes ranged 
from moderate to very high. The classification 
was based entirely upon soil characteristics 
and was independent of vegetation; as a result, 
the confounding effects of range condition 
were eliminated. Factors considered in evaluat- 
ing the potential erosion hazard of a soil in- 
cluded soil thickness, structure, texture, size 
and strength of the peds, and rates of infiltra- 
tion and percolation. 
b. A colored transparent erosion hazard 
overlay was made to the same scale as the base 
map. 
3. A colored transparent overlay was made 
showing range condition and trend and pri- 
mary and secondary range. 
Ranges were classified into condition and 
trend classes and as primary or secondary 
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