Conversion of Prime Farmland Soils on Natural Resource 

Lands To Urban Lands Findings

State of Oregon

1997 National Resources Inventory Results

(Revised December 2000) 

See Conversion of Lands Topic List for detailed results.

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Conversion of Prime Farmland Soils to Urban Lands

An additional aspect of the loss of farmland to urbanization is the amount of prime farmland soils (those 

best suited to crop production) that are removed from the natural resource base.

Prime farmland soils are defined in the USDA-NRCS Title 430 National Soil Survey Handbook, issued 

November 1996, as follows: "Prime farmland is land that has the best combination of physical and chemical 

characteristics for producing food, feed, forage, fiber, and oilseed crops and that is available for these uses. 

It has the combination of soil properties, growing season, and moisture supply needed to produce sustained 

high yields of crops in an economic manner if it is treated and managed according to acceptable farming 

methods. . . . "

Conversion of prime farmland soils to urban lands from 1982 to 1997 totaled an estimated 85,000 acres out 

of the 249,800 total acres converted from natural resource lands.

Conversion of Prime Farmland Soils to Urban Lands 1982 to 1997 Estimates

Land Type Total Acres Converted Acres Prime Soils Converted Prime as % of Total Converted

Cropland 63,000 44,400 70%

Pastureland 58,600 24,300 41%

Rangeland 22,700 3,300 15%

Forestland 105,500 13,000 12%
Total Acres 249,800 85,000 34%

Chart for Prime Soils Converted to Urban Compared to Total Converted to Urban 1982 to 1997 (17 KB)

Table for Prime Soils Converted to Urban Compared to Total Converted to Urban 1982 to 1997 (8 KB) 

 Text Version of Prime Soils Converted to Urban Compared to Total Converted to Urban 1982 to 

1997.

 Details for Prime Soils Converted to Urban Compared to Total Converted to Urban 1982 to 1997.

The rate of conversion of prime soils to urban lands increased from an estimated 5,000 acres per year 

between 1982 and 1992 to 7,000 acres per year from 1992 to 1997. This is an increase of 40%. The rate of 

increase doubled on pastureland and forestland. NRI results indicate little change in the average annual rate 

of conversion of prime soils on rangelands.

Estimated Annual Rate of Conversion of Prime Soils to Urban Lands for '1982 to 1992' 

compared to '1992 to 1997' by Acres Per Year

Land Type 1982 to 1992 1992 to 1997 % Change

Cropland 2,930 3,020 + 3.1%

Pastureland 1,190 2,480 + 108.4%

Rangeland 230 200 - 13.0%

Forestland 650 1,300 + 100.0%

Total Acres/Year 5,000 7,000 + 40.0%

Chart for Annual Rate of Conversion of Prime Soils Converted to Urban Compared to Total Lands 

Converted to Urban (18 KB)

Table for Annual Rate of Conversion of Prime Soils Converted to Urban Compared to Total Lands 

Converted to Urban (8 KB) 

 Text Version of Annual Rate of Conversion of Prime Soils Converted to Urban Compared to Total 

Lands Converted to Urban.

 Details for Annual Rate of Conversion of Prime Soils Converted to Urban Compared to Total Lands 

Converted to Urban.
To see all results, select Geographic Area.

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