Highly Erodible and Non-Highly Erodible Cropland, by Region and Year
Estimates presented here are based upon the latest information from the National Resources Inventory (NRI). The NRI is a longitudinal sample survey based upon scientific statistical principles and procedures. It is conducted by the U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS), in cooperation with Iowa State University's Center for Survey Statistics and Methodology. These results are based upon the 2007 NRI, which provides nationally consistent data for the 25-year period 1982–2007. Estimates here cover the contiguous 48 states. Separate estimates include Hawaii, Alaska, and the Caribbean.
Margins of error are reported for each NRI estimate and must be considered at all scales of analysis. The margin of error is used to construct the 95 percent confidence interval for the estimate. 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.
Table 38. Highly Erodible (HEL) Cropland and Non-Highly Erodible (Non-HEL) Cropland, by Farm Production Region and Year, in Thousands of Acres, with Margins of Error
Region
Year
HEL Cropland Eroding At or Below Soil Loss Tolerance Rates
HEL Cropland Eroding Above Soil Loss Tolerance Rates
Total HEL Cropland
Non-HEL Cropland Eroding At or Below Soil Loss Tolerance Rates
Non-HEL Cropland Eroding Above Soil Loss Tolerance Rates
Total Non-HEL Cropland
Appalachian
1982
3,705.1
±199.3
6,140.4
±228.1
9,845.5
±274.5
9,792.6
±204.4
2,952.4
±174.1
12,745.0
±233.1
1987
3,583.9
±168.1
5,484.4
±235.3
9,068.3
±286.4
9,352.4
±220.8
2,767.7
±143.6
12,120.1
±232.3
1992
3,821.3
±148.7
4,297.3
±182.9
8,118.6
±265.2
9,257.2
±255.0
2,262.5
±138.8
11,519.7
±263.9
1997
4,273.0
±156.9
3,733.9
±146.5
8,006.9
±204.9
9,338.6
±224.1
1,821.6
±125.3
11,160.2
±242.5
2002
4,876.1
±316.4
3,099.3
±192.4
7,975.4
±345.9
9,508.7
±358.5
1,420.7
±151.8
10,929.4
±347.0
2007
4,807.7
±490.8
2,824.3
±243.4
7,632.0
±512.5
9,472.6
±466.9
968.8
±160.3
10,441.4
±453.7
Corn Belt
1982
4,233.8
±215.5
18,363.5
±410.0
22,597.3
±475.6
47,840.2
±503.4
21,798.7
±456.2
69,638.9
±581.1
1987
4,551.6
±208.8
17,153.2
±387.2
21,704.8
±461.6
52,282.2
±509.1
16,905.3
±349.3
69,187.5
±567.7
1992
5,196.3
±250.0
14,764.4
±364.2
19,960.7
±441.7
56,686.8
±479.5
11,063.4
±321.5
67,750.2
±570.9
1997
6,206.8
±182.2
14,149.2
±361.6
20,356.0
±413.1
59,807.4
±494.6
7,787.2
±261.7
67,594.6
±554.4
2002
6,006.2
±392.9
14,469.6
±458.5
20,475.8
±543.7
59,726.3
±705.9
7,501.3
±306.3
67,227.6
±690.0
2007
5,950.6
±476.5
14,303.0
±641.0
20,253.6
±734.6
59,808.4
±973.7
6,855.4
±491.5
66,663.8
±936.2
Delta States
1982
541.5
±66.1
2,178.1
±173.0
2,719.6
±212.4
13,609.2
±544.9
5,544.9
±248.6
19,154.1
±565.9
1987
623.2
±90.1
1,593.7
±136.9
2,216.9
±153.6
13,494.1
±514.2
5,165.6
±201.2
18,659.7
±517.5
1992
530.5
±66.4
1,058.1
±106.3
1,588.6
±134.1
13,767.3
±460.2
4,013.2
±197.8
17,780.5
±510.2
1997
494.3
±62.2
884.3
±107.4
1,378.6
±124.0
13,621.9
±489.5
3,571.3
±233.9
17,193.2
±527.3
2002
496.9
±126.3
748.9
±152.7
1,245.8
±216.7
13,362.1
±610.4
3,176.9
±346.4
16,539.0
±563.7
2007
431.7
±143.5
725.7
±169.7
1,157.4
±223.2
13,086.1
±578.0
2,947.2
±377.6
16,033.3
±611.2
Lake States
1982
2,078.7
±122.7
4,064.2
±164.4
6,142.9
±204.3
25,169.7
±590.8
12,466.2
±364.4
37,635.9
±633.8
1987
2,026.5
±128.3
3,931.3
±163.6
5,957.8
±199.0
23,901.3
±570.3
13,048.4
±414.8
36,949.7
±676.2
1992
2,224.3
±151.0
3,145.6
±157.3
5,369.9
±178.8
23,915.8
±504.8
11,818.6
±308.1
35,734.4
±630.5
1997
2,221.6
±153.3
3,148.7
±126.9
5,370.3
±203.0
24,550.5
±573.3
10,558.0
±351.0
35,108.5
±673.6
2002
1,981.7
±246.7
3,183.9
±267.3
5,165.6
±318.0
24,212.3
±717.5
10,062.0
±490.7
34,274.3
±746.3
2007
1,923.7
±284.4
3,245.6
±287.9
5,169.3
±383.4
25,839.6
±807.2
7,552.0
±679.4
33,391.6
±826.7
Mountain
1982
10,609.1
±680.8
16,467.9
±711.4
27,077.0
±1,056.9
11,043.4
±640.5
5,005.4
±428.7
16,048.8
±772.5
1987
9,403.8
±465.0
15,757.7
±833.8
25,161.5
±1,033.7
10,021.4
±539.6
5,057.3
±448.5
15,078.7
±754.5
1992
9,938.9
±602.6
13,482.0
±837.8
23,420.9
±1,072.7
10,256.3
±610.6
3,735.4
±311.8
13,991.7
±705.3
1997
11,917.6
±800.9
11,115.2
±629.3
23,032.8
±1,067.8
11,486.0
±588.6
2,549.9
±257.6
14,035.9
±684.7
2002
10,886.2
±761.9
10,519.1
±924.8
21,405.3
±1,050.6
11,287.1
±891.2
2,122.4
±267.2
13,409.5
±869.6
2007
10,378.8
±1,027.7
9,822.4
±1,031.0
20,201.2
±1,139.1
10,345.8
±855.3
2,476.1
±397.6
12,821.9
±1,002.4
Northeast
1982
3,613.9
±158.3
3,397.3
±112.7
7,011.2
±191.0
8,327.3
±317.3
1,398.3
±82.2
9,725.6
±312.3
1987
3,144.0
±163.9
3,581.1
±134.7
6,725.1
±193.7
8,278.3
±318.7
1,237.5
±87.6
9,515.8
±317.2
1992
3,273.7
±125.4
3,217.5
±133.7
6,491.2
±197.2
8,079.9
±303.2
1,134.9
±79.8
9,214.8
±309.2
1997
3,333.2
±106.2
2,959.9
±142.3
6,293.1
±192.8
7,899.7
±339.8
948.8
±77.2
8,848.5
±329.7
2002
3,254.7
±255.3
2,641.5
±211.1
5,896.2
±307.2
7,463.6
±408.9
972.5
±143.7
8,436.1
±416.4
2007
3,271.3
±246.5
2,383.4
±244.1
5,654.7
±297.6
7,314.9
±419.6
738.0
±130.5
8,052.9
±448.1
Northern Plains
1982
10,458.5
±484.7
14,777.0
±409.9
25,235.5
±534.7
49,420.9
±677.1
18,668.0
±360.1
68,088.9
±732.7
1987
9,762.9
±423.4
14,852.9
±426.9
24,615.8
±554.4
49,493.8
±680.3
18,913.3
±394.9
68,407.1
±681.2
1992
10,582.8
±436.7
10,974.3
±367.1
21,557.1
±517.6
52,202.7
±640.3
13,099.9
±377.9
65,302.6
±636.9
1997
12,233.9
±459.8
9,662.7
±314.9
21,896.6
±550.5
53,992.7
±582.4
11,780.0
±260.2
65,772.7
±638.9
2002
11,896.6
±675.2
10,135.7
±605.3
22,032.3
±832.3
52,255.4
±931.4
12,818.2
±587.8
65,073.6
±1,131.8
2007
12,044.0
±859.2
9,502.1
±674.1
21,546.1
±990.7
50,763.4
±1,277.1
13,568.3
±717.0
64,331.7
±1,322.7
Pacific
1982
1,138.4
±173.7
4,109.1
±326.3
5,247.5
±410.6
14,799.8
±770.6
2,491.2
±235.2
17,291.0
±816.0
1987
1,258.0
±194.2
3,567.8
±306.6
4,825.8
±377.1
14,072.3
±753.5
2,461.5
±284.0
16,533.8
±850.5
1992
1,191.2
±196.9
3,306.0
±262.7
4,497.2
±350.7
13,842.9
±747.4
2,238.6
±282.0
16,081.5
±847.9
1997
1,242.7
±206.8
3,007.0
±256.2
4,249.7
±361.1
13,667.6
±752.1
2,129.1
±289.2
15,796.7
±858.5
2002
1,210.3
±200.2
2,968.1
±321.3
4,178.4
±375.2
13,594.5
±808.3
2,029.0
±345.0
15,623.5
±996.4
2007
1,468.4
±287.9
2,718.9
±372.8
4,187.3
±568.8
13,544.0
±1,032.0
1,825.0
±391.8
15,369.0
±1,184.4
Southeast
1982
618.2
±70.4
2,433.4
±132.1
3,051.6
±151.8
10,833.1
±371.8
4,344.4
±135.2
15,177.5
±409.6
1987
677.7
±92.5
1,956.1
±120.4
2,633.8
±144.6
10,169.1
±407.0
3,661.6
±153.8
13,830.7
±430.7
1992
573.7
±92.8
1,379.9
±128.5
1,953.6
±156.7
9,284.7
±392.1
3,123.7
±138.8
12,408.4
±417.6
1997
591.0
±57.3
1,093.1
±102.5
1,684.1
±119.0
8,404.2
±402.0
2,977.1
±132.8
11,381.3
±440.2
2002
672.6
±112.3
830.1
±126.9
1,502.7
±145.3
8,241.2
±508.1
2,530.9
±236.8
10,772.1
±537.9
2007
670.0
±152.2
630.0
±162.8
1,300.0
±240.3
7,979.1
±629.9
2,048.3
±266.3
10,027.4
±691.7
Southern Plains
1982
4,410.7
±331.6
11,923.3
±491.4
16,334.0
±578.4
18,736.4
±470.0
10,042.7
±481.4
28,779.1
±566.5
1987
3,684.9
±268.8
11,112.7
±429.7
14,797.6
±512.4
18,267.3
±469.2
9,287.6
±367.3
27,554.9
±573.4
1992
3,858.4
±245.7
9,196.9
±457.7
13,055.3
±514.3
17,864.3
±459.5
7,779.4
±337.4
25,643.7
±621.5
1997
4,194.3
±232.6
8,146.0
±366.3
12,340.3
±488.6
18,050.2
±472.5
6,587.9
±280.6
24,638.1
±607.2
2002
3,812.5
±342.9
7,495.6
±437.7
11,308.1
±566.8
17,217.3
±624.6
6,411.6
±425.0
23,628.9
±630.2
2007
3,185.5
±474.5
7,484.4
±726.1
10,669.9
±823.4
15,532.7
±727.9
6,586.3
±565.4
22,119.0
±783.1
Notes:
• Cropland includes cultivated and non-cultivated cropland.
