Erosion on Highly 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 39. Erosion on Highly Erodible (HEL) Cropland and Non-Highly Erodible (Non-HEL) Cropland, by Farm Production Region and Year,
in Millions of Tons per Year, with Margins of Error
Region
Year
Highly Erodible (HEL) Cropland
Non-Highly Erodible (Non-HEL) Cropland
Erosion on Land Eroding At or Below Soil Loss Tolerance Rates (T)
Erosion on Land Eroding Above Soil Loss Tolerance Rates (T)
Erosion on Land Eroding At or Below Soil Loss Tolerance Rates (T)
Erosion on Land Eroding Above Soil Loss Tolerance Rates (T)
Erosion at T
Erosion above T
Total Erosion
Erosion at T
Erosion above T
Total Erosion
Appalachian
1982
3.9
±0.3
21.2
±0.8
88.5
±4.6
109.7
±5.1
19.5
±0.6
12.7
±0.7
8.5
±0.5
21.2
±1.2
1987
3.4
±0.3
19.1
±0.8
78.5
±4.8
97.6
±5.4
18.2
±0.6
12.1
±0.6
7.4
±0.4
19.5
±0.9
1992
3.9
±0.2
14.8
±0.6
47.3
±2.7
62.1
±3.2
18.0
±0.6
9.9
±0.6
5.5
±0.4
15.5
±1.0
1997
4.9
±0.2
12.8
±0.5
33.4
±2.7
46.2
±3.0
16.7
±0.5
8.1
±0.6
3.7
±0.4
11.8
±0.9
2002
5.6
±0.5
10.5
±0.6
25.0
±2.1
35.5
±2.5
14.4
±0.8
6.3
±0.7
3.1
±0.4
9.4
±1.0
2007
5.6
±0.7
9.5
±0.8
22.9
±3.2
32.4
±3.7
13.2
±0.8
4.3
±0.7
2.4
±0.6
6.8
±1.3
Corn Belt
1982
7.3
±0.4
75.0
±1.7
299.5
±7.6
374.5
±8.8
131.7
±1.7
94.9
±2.0
81.2
±2.1
176.1
±3.9
1987
8.0
±0.4
70.4
±1.6
231.5
±7.2
301.9
±8.3
127.8
±1.6
72.9
±1.5
54.0
±1.6
126.9
±2.8
1992
8.8
±0.4
61.0
±1.6
156.5
±5.7
217.6
±6.9
129.5
±1.6
46.9
±1.4
27.0
±1.2
73.9
±2.4
1997
10.0
±0.4
58.8
±1.5
123.3
±4.1
182.1
±5.2
122.3
±1.5
32.9
±1.1
15.8
±0.9
48.7
±1.9
2002
9.2
±0.7
60.3
±2.0
136.0
±7.4
196.3
±8.7
117.9
±2.2
31.8
±1.4
14.7
±0.9
46.5
±2.2
2007
9.6
±0.9
59.6
±2.8
134.5
±8.2
194.0
±10.1
112.9
±2.8
28.7
±2.2
13.8
±1.5
42.6
±3.6
Delta States
1982
0.6
±0.1
7.7
±0.6
32.1
±3.7
39.8
±4.0
39.1
±1.6
25.2
±1.2
11.3
±0.6
36.5
±1.6
1987
0.8
±0.1
5.6
±0.5
21.2
±2.9
26.8
±3.3
37.2
±1.3
23.3
±0.9
10.1
±0.7
33.4
±1.4
1992
0.6
±0.1
3.6
±0.4
12.3
±1.8
15.9
±2.1
36.4
±1.4
18.0
±0.9
7.6
±0.6
25.6
±1.4
1997
0.6
±0.1
3.1
±0.4
8.2
±1.2
11.3
±1.5
35.8
±1.4
15.9
±1.1
6.8
±0.5
22.7
±1.5
2002
0.6
±0.2
2.6
±0.5
7.2
±1.5
9.9
±1.9
33.7
±1.8
14.1
±1.6
6.0
±1.0
20.1
±2.5
2007
0.4
±0.2
2.5
±0.7
7.7
±6.0
10.3
±6.5
31.1
±1.7
13.1
±1.7
5.5
±1.2
18.6
±2.6
Lake States
1982
4.3
±0.3
17.0
±0.8
46.3
±3.0
63.3
±3.6
61.4
±1.9
58.6
±1.8
81.1
±3.3
139.7
±4.9
1987
4.0
±0.3
16.5
±0.7
45.9
±3.2
62.4
±3.7
59.3
±1.7
61.5
±2.0
93.3
±4.2
154.8
±5.9
1992
3.8
±0.3
13.2
±0.7
34.3
±2.6
47.5
±3.2
56.5
±1.4
55.8
±1.5
79.2
±3.1
135.0
±4.0
1997
4.5
±0.3
13.1
±0.6
29.0
±2.0
42.1
±2.4
55.8
±1.4
49.8
±1.7
68.7
±3.1
118.5
±4.4
2002
4.0
±0.6
13.4
±1.2
31.0
±3.0
44.4
±3.9
55.5
±1.8
47.4
±2.3
62.2
±4.7
109.5
±6.4
2007
4.1
±0.8
13.6
±1.3
28.9
±4.4
42.5
±5.3
55.6
±3.2
35.3
±3.1
39.2
±4.9
74.5
±7.7
Mountain
1982
22.3
±1.9
70.9
±3.3
241.9
±10.9
312.8
±13.0
20.5
±1.6
24.3
±2.1
36.1
±4.3
60.4
±6.2
1987
19.2
±1.4
68.0
±4.0
225.7
±14.5
293.7
±17.3
17.3
±1.0
24.7
±2.2
36.7
±4.3
61.3
±6.2
1992
19.7
±1.9
58.3
±3.9
173.1
±14.3
231.4
±16.9
18.4
±1.3
18.3
±1.6
21.3
±2.2
39.6
±3.5
1997
24.1
±2.3
47.2
±3.0
126.1
±9.6
173.3
±11.8
20.1
±1.3
12.4
±1.3
13.9
±1.8
26.3
±2.9
2002
22.7
±2.5
45.5
±4.2
128.8
±14.3
174.3
±16.8
17.8
±1.5
10.4
±1.3
12.5
±1.9
22.8
±3.0
2007
19.8
±2.8
42.4
±4.6
130.2
±18.4
172.6
±21.9
14.5
±2.0
12.1
±1.9
15.2
±4.2
27.3
±5.8
Northeast
1982
3.1
±0.2
10.9
±0.3
30.7
±2.0
41.6
±2.2
8.2
±0.3
4.9
±0.3
3.1
±0.2
8.0
±0.5
1987
2.7
±0.2
11.4
±0.4
31.9
±1.9
43.3
±2.2
8.3
±0.3
4.3
±0.3
2.7
±0.3
7.0
±0.6
1992
2.8
±0.2
10.3
±0.4
22.8
±1.5
33.1
±1.8
8.1
±0.3
3.9
±0.3
2.2
±0.2
6.1
±0.5
1997
3.1
±0.2
9.5
±0.5
18.6
±1.3
28.1
±1.7
8.1
±0.3
3.3
±0.3
1.7
±0.2
4.9
±0.4
2002
3.1
±0.3
8.4
±0.7
17.2
±1.5
25.7
±2.0
7.1
±0.5
3.4
±0.5
1.8
±0.4
5.2
±0.9
2007
3.4
±0.4
7.5
±0.8
15.5
±1.8
23.0
±2.5
6.3
±0.5
2.5
±0.4
1.4
±0.2
3.8
±0.6
Northern Plains
1982
26.1
±1.3
65.1
±1.9
163.8
±6.3
228.9
±7.8
142.0
±2.4
88.2
±1.7
99.5
±2.8
187.7
±4.2
1987
25.3
±1.1
65.8
±2.0
152.3
±4.9
218.1
±6.5
138.4
±2.0
89.6
±1.8
103.1
±3.3
192.7
±4.7
1992
26.1
±1.2
48.6
±1.8
97.8
±4.3
146.4
±5.6
135.8
±2.2
62.0
±1.8
56.7
±2.1
118.7
±3.6
1997
27.5
±1.2
42.7
±1.5
74.2
±3.2
117.0
±4.4
125.2
±1.9
55.8
±1.2
51.0
±2.0
106.8
±2.8
2002
26.1
±2.1
44.4
±2.7
85.9
±8.5
130.3
±10.6
125.7
±3.0
60.7
±2.8
58.8
±3.7
119.5
±6.1
2007
24.7
±2.4
42.0
±2.8
80.1
±7.3
122.0
±9.0
122.4
±3.3
64.5
±3.5
66.4
±4.7
130.9
±7.9
Pacific
1982
1.4
±0.2
14.7
±1.4
62.2
±8.7
76.9
±9.6
14.6
±1.5
10.3
±1.1
12.8
±1.7
23.1
±2.6
1987
1.5
±0.3
13.5
±1.3
60.8
±7.8
74.3
±8.8
13.7
±1.4
10.7
±1.3
12.9
±1.7
23.6
±2.9
1992
1.2
±0.2
12.6
±1.1
49.5
±9.5
62.0
±10.1
12.6
±1.3
9.8
±1.3
11.3
±2.0
21.1
±3.2
1997
1.3
±0.2
11.7
±1.1
34.4
±6.3
46.0
±6.9
12.5
±1.3
9.3
±1.3
10.5
±1.8
19.8
±3.0
2002
1.1
±0.2
11.7
±1.5
38.9
±9.2
50.6
±9.6
11.0
±1.5
9.0
±1.5
9.8
±2.1
18.8
±3.5
2007
1.7
±0.4
10.7
±2.0
32.0
±10.9
42.7
±11.7
11.1
±1.9
8.1
±1.9
10.8
±2.5
19.0
±4.3
Southeast
1982
0.8
±0.2
9.0
±0.6
29.5
±2.5
38.5
±2.9
21.6
±0.7
19.9
±0.6
12.0
±0.6
31.8
±1.1
1987
0.9
±0.2
7.1
±0.4
22.6
±1.9
29.7
±2.3
19.0
±0.7
16.8
±0.7
10.9
±0.7
27.6
±1.3
1992
0.6
±0.2
5.0
±0.5
14.8
±1.8
19.8
±2.2
16.4
±0.7
14.3
±0.6
9.0
±0.6
23.3
±1.1
1997
0.6
±0.1
3.9
±0.4
11.4
±1.4
15.4
±1.8
14.5
±0.6
13.6
±0.6
9.1
±0.6
22.7
±1.2
2002
0.6
±0.2
3.0
±0.5
8.3
±1.5
11.3
±1.9
13.4
±0.9
11.7
±1.2
7.4
±0.9
19.1
±1.9
2007
0.6
±0.2
2.3
±0.6
6.7
±3.0
9.0
±3.5
11.7
±1.2
9.4
±1.3
7.3
±1.0
16.7
±2.1
Southern Plains
1982
9.8
±0.8
52.5
±2.3
327.7
±21.5
380.2
±23.0
45.9
±1.5
49.5
±2.3
76.7
±4.6
126.2
±6.6
1987
8.5
±0.7
48.9
±2.1
276.3
±13.4
325.2
±15.0
45.3
±1.3
45.7
±1.8
68.5
±3.5
114.2
±5.0
1992
8.9
±0.6
40.3
±2.3
196.9
±13.1
237.1
±14.9
44.6
±1.2
38.3
±1.6
51.2
±2.4
89.5
±3.7
1997
11.0
±0.6
35.2
±1.9
181.8
±12.9
217.0
±14.4
44.5
±1.3
32.4
±1.4
49.7
±2.5
82.1
±3.5
2002
9.2
±1.0
32.6
±2.0
137.7
±14.6
170.3
±16.0
42.2
±2.4
31.6
±2.1
41.2
±4.4
72.8
±6.1
2007
8.8
±1.4
33.1
±3.5
136.6
±19.3
169.7
±21.0
39.4
±2.4
32.5
±2.7
37.2
±3.6
69.7
±5.9
Notes:
• Cropland includes cultivated and non-cultivated cropland.
