The rate of conversion of prime farm acreage and forests to urban land slowed in Washington from 2002-07, according to a report issued Wednesday by the U.S. Department of Agriculture's Natural Resources Conservation Service.
Washington now has about 2 million acres of urban land, the agency's National Resources Inventory said.
About 864,000 acres of land were converted to urban use between 1982 and 2007, but the amount converted from 2002-07 was about half the amount, the report said.
Forestland represented about 60 percent of the land converted to urban from 1982 to 2007, according to the report.
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The report estimates that Washington now has 1.3 million acres of prime farmland in 2007, compared to 1.42 million acres in 1982.
Jan Carlson, a natural resource specialist with the NRCS, said prime farmlands "are generally the most productive and least erodible soils we have, so these numbers are especially important to land managers and planners. In addition, development isolates tracts of former farmland, which degrades wildlife habitat and makes agricultural production less efficient."
The report also shows that total cropland erosion -- sheet, rill and wind -- in Washington declined from 1982 to 2007.
"The most dramatic soil erosion reductions occurred between 1987 and 1997 with the introduction of the Conservation Reserve Program, a program that provides rental payment to farmers to enroll highly erodible cultivated land into permanent grass for wildlife habitat and resource protection," he said.
Carlson said that cultivated crop-land acreage declined from 6.9 million acres in 1982 to 5.3 million acres in 2007.