National Resource Inventory (NRI)

Illinois Highlights
1997 National Resources Inventory
(Revised December 2000)

Significant findings for 1997 are as follows:

Surface Area

In 1997, the total surface area of Illinois was 36,058,700 acres.

*Includes urban and rural transportation lands
** Conservation Reserve Program
*** Includes farmsteads, farm structures, field windbreaks, barren land, and marshland

Illinois Highlights
1997 National Resources Inventory
(Revised December 2000)

Land Cover/Use

Land Cover/Use is a term that includes categories of land cover and categories of land use. Land cover is the vegetation or other kind of material that covers the land surface. Land use is the purpose of human activity on the land; it is usually, but not always, related to land cover. The NRI uses the term land cover/use to identify the categories that account for all the surface areas of the United States.

Land cover/use changes of non-federal rural land in Illinois are as follows:

Illinois Highlights
1997 National Resources Inventory
(Revised December 2000)

Erosions Reductions

The erosion rate on Illinois' cropland has steadily declined over the 15-year period. Conservation treatments such as no-till, terraces, conservation tillage, strip cropping, contour farming, and conservation cover planted on CRP land have contributed to this decline. The NRI divides erosion into two main categories, wind and water. Wind erosion data is not collected in Illinois.

Sheet and Rill Erosion (water) on Cropland

Average sheet and rill erosion rates on Illinois cropland declined by 35 percent over the 15-year period.

Average sheet and rill erosion rates on pastureland decreased from 1.6 tons per acre in 1982 to 1.0 ton per acre in 1997.

Since 1982 average sheet and erosion rates on pastureland was reduced by 37.5 percent, but since 1992 have remained level.

At an average rate of 1.0 ton per acre or less, soil erosion poses little threat to pastureland productivity statewide.

Prime Farmland

Prime farmland is land that has the best combination of physical characteristics for producing food, feed, forage, and oilseed crops and is available for these uses. Illinois had 20,894,000 acres of soils classified as prime farmland in 1997.  About 18,679,800 (89.4%) of these acres were used as cropland. The remaining amount was used for pastureland, forestland, CRP land, and other rural land.