Summary 2003 Annual NRI

Montana Land Use and Erosion Results

These results are based upon the 2003 Annual NRI, which statistically updates the 1997 NRI results with data collected during 2000 - 2003.  Estimates provided below and in associated tables and charts represent 2003 conditions only and cannot be used to evaluate change from previous inventory cycles. State level change estimates and associated trending information from the 2003 Annual NRI are not currently available.  As each successive annual NRI is conducted, more results will become available for regional, state, and eventually sub-state level analyses.  Estimates are being released when they meet NRI statistical standards and are scientifically credible in accordance with NRCS policy, and Office of Management and Budget (OMB) and USDA quality of information guidelines. 

Margins of error (at the 95 percent confidence level) are reported for NRI estimates.  The lower bound of the interval is obtained by subtracting the margin of error from the estimate; the upper bound is obtained by adding the margin of error to the estimate.  A 95 percent confidence interval means that in repeated samples from the same population, 95 percent of the time the true underlying population parameter will be contained within the lower and upper bounds of the interval.  Acreages for CRP, Federal Land, and total surface area are established through geospatial processes and administrative records; therefore, statistical margins of error are not applicable and shown as n/a.

See the National Resources Inventory 2002 and 2003 Annual NRI for a glossary of key terms.

Land Use

Montana contains about 94.1 million acres.  Approximately 69% (nearly 65 million acres) of this area is in non-Federal rural lands. In 2003, non-Federal rural lands were predominantly rangeland (56.5%) and cropland (22.4%). Grazing lands (including non-Federal rangeland, pastureland, and grazed forest land) totaled approximately 43.5 million acres or 67% of the rural land base. Of the cropland, 78.5% is cultivated and 22.5% is non-cultivated.

• Land Use Tables
• Montana 2003 Non-Federal Rural Land Cover/Use, Pie Chart
• Montana 2003 Non-Federal Grazing Lands, Pie Chart
• Montana 2003 Cropland, Pie Chart

Erosion

In 2003, total soil erosion on Montana croplands was estimated at 59.4 million tons per year with over 70% from wind erosion.  Water (sheet and rill) erosion rates on a per acre basis were 1.1 tons per acre per year.  Wind erosion rates were 2.9 tons per acre per year.  About 11.1 million acres (76.3% of all cropland) were eroding at or below soil loss tolerance rates. Approximately, 3.4 million acres (23.7%) were eroding above soil loss tolerance rates.  In Montana, approximately 60% of the total 2003 cropland occurred on highly erodible land (HEL). Sixty-six percent of the cropland on highly erodible land was eroding at or below soil loss tolerance rates.  Over 92% of the cropland on non-highly erodible land was eroding at or below soil loss tolerance rates. 

• Erosion Tables
• Montana 2003 Soil Erosion by Wind and Water, Pie Chart
• Montana 2003 Highly Erodible Cropland (HEL) in Relation to Soil Loss Tolerance (T), Pie Chart
• Montana 2003 Non-HEL in Relation to Soil Loss Tolerance (T), Pie Chart

Last Modified: 09/05/2008