The use of inventoried wetlands differs from their 

 land cover (table 5). About 50 percent of wetlands 

 are used for wood production, while 20 percent are 

 used for agriculture. Seven percent of wetlands are 

 designated for wild uses such as refuges and parks. 

 More than 20 percent of wetlands are idle or could 

 not be assigned a use, again indicating the residual 

 nature of much wetland. Palustrine wetlands make 

 up almost all the agricultural uses as well as all 

 forest used for wood production ("wood produc- 

 tion" means that no other specific use is designated 

 for a forested wetland). 



Farm Potential of Remaining Wetlands 



Since the vast majority of wetlands converted to 

 farming from the mid-1950's to the mid-1970's were 

 palustrine, assessment of wetland conversion poten- 

 tial can be restricted to that class. Almost all 



Table 5 — Use of non-Federal wetlands, 1982 



'Defined in (8). 



'Includes areas designated wilderness, wildlife, recreation, 

 nature study, and research and experimentation. 



'Includes commercial, industrial, institutional, transmission, 

 waste disposal, military, and transportation uses. 



Source: 1^82 National Resources Inventory, USDA Soil Conser- 

 vation Service. 



wetlands (96 percent) inventoried in 1982 were 

 palustrine (table 6). USDA restricts technical 

 assistance for agricultural drainage to seasonally 

 flooded basins or flats and inland fresh meadows, 

 which are wetland types 1 and 2 in the classifica- 

 tion of Circular 39 (50). In 1982 about 44 percent of 

 palustrine wetlands were wetland types 1 and 2. 

 Thus, a total of 70.7 million acres of non-Federal 

 wetlands could be converted to farmland, and 31.4 

 million acres would be eligible for USDA technical 

 assistance for drainage. 



Soil Conservation Service technicians conducting 

 the 1982 NRI rated inventoried land on its potential 

 for conversion to cropland and the type of effort re- 

 quired for conversion, and listed reasons preventing 

 conversion (54). Of 70.7 million acres of non- 

 Federal palustrine wetlands, only 5.1 million acres 

 were rated as having high or medium potential for 

 conversion to cropland in 1982 (table 7). A quarter 

 of all palustrine wetlands were either already 

 cropland or in an irreversible use. Another quarter 

 were rated as having no potential for conversion, 

 and 40 percent were considered unlikely to be con- 

 verted soon. 



Almost 85 percent of high- and medium-potential 

 palustrine wetlands (4.3 million acres) could be 

 brought into crop production with no effort or with 

 minor work on the farm. Slightly more than 3 million 

 of the 4.3 million acres would require drainage. 

 Some 470,000 wetland acres have other soil condi- 

 tions, such as low fertility, high erosion potential, 

 alkalinity or salinity, or restrictive root zones, in 

 addition to wetness, that restrict their conversion 

 potential. 



Many areas that had large losses of wetlands due to 

 agricultural conversion between the mid-1950's and 



Table 6 — Non-Federal wetlands cross-classified by system and type, 1982 



• - Fewer than 100,000 acres. 



•Defined in (8). 



'Defined in (38). 



'Detail may not add to totals due to rounding. 



Source: 1982 National Resources Inventory, USDA Soil Conservation Service. 



