Minnesotans For Sustainability©

 

Home ] Feedback Please ] Table of Contents ] Search MFS ] MFS News ]

Sustainable Society:  A society that balances the environment, other life forms, and human interactions over an indefinite time period.

 

 

 

 

 


 

America's Northern Plains

An Overview and Assessment of Natural Resources*


R. D. Nielsen, G. B. Muckel, A. Mendenhall, D. T. Lightle,
B. C. Wight, H.R. Sinclair, H. P. Terpstra,
S. W. Waltman, J. D. Vrana, David Buland, and S. C. Stover

United States Department of Agriculture
Natural Resources Conservation Service
August 1997

 

Abstract
Basic Regional Land Resources
    Figure 1. Northern Plains region physiography and MLRAs.
    Diversity
    National Significance
Soil Quality and Health
    Soil Fragility
        Figure 2. Rangelands with fragile soils in the Northern Plains region
        Figure 3. Forest lands with fragile soils in the Northern Plains region
    Conservation Needs
        Table 1. Highly Erodible Land (HEL) status and CRP acres in the Northern Plains region
        Figure 4. Distribution of Conservation Reserve Program (CRP) lands in the Northern Plains region
    Erosion rates
    Irrigation and erosion
          Figure 5. Irrigated cropland 1992, Northern Plains region
    Conservation tillage
        Table 2. Conservation tillage management by state
    Soil Salinity
    Figure 6. Salinity-affected landscapes of the Northern Plains region
Climate Change
    Temperature
    Evapotranspiration and growing-degree days
    Potential effects of changes
        Table 3. Comparison of climatic characteristics during the "Dust Bowl" years (1931 to 1940) with the 1961 to 1990 normals across the Northern Plains Region
Water Supply
    Figure 7. Water level changes in the High Plains Aquifer, pre-development to 1980
    Figure 8. Water level changes in the High Plains Aquifer, 1980-1990
Water Quality
    Surface Water Quality
        Table 4. Surface water quality summary for the Northern Plains states and nationwide
        Figure 9. Comparison of Northern Plains region and national erosion rates
    Groundwater Quality
        Figure 10. Distribution of Nitrate-N concentrations in groundwater in the contiguous United States
Grazing Lands
    Figure 11. Breakdown of cattle numbers in the Northern Plains
    Figure 12. Tons per acre of soil loss by land use in the Northern Plains
    Figure 13. Range condition classes by acres in the Northern Plains
    Figure 14. Acres of apparent trend on rangeland in the Northern Plains
    Figure 15. Rangeland soils with high potential for wind erosion in the northern Plains region
Forest Lands and Windbreaks
Wetlands
Economics
    Population
    Settlement Changes
        Figure 16. Population density in the Northern Plains
    Per Capita Income
        Figure 17. Northern Plains per capita income by county. The US average income was $18,696 in 1990
    Agricultural Systems
        Farming Changes
    Regional Monitoring and Research Infrastructure
Conclusion
References

 

northern_plains_cover.jpg (160344 bytes)
(Click thumbnails to enlarge)

Abstract:
This report provides a general overview of the basic natural land resources in the Northern Plains region and their sustainability over time. It also describes the primary external forces (both natural and human caused) which are likely to affect those resources and it identifies projected changes in the resource base.


Basic Region Land Resources

The Northern Plains region consists of roughly 420 million acres, distributed across 55 Major Land Resource Areas (MLRAs). The MLRAs are geographic areas characterized by a particular pattern of soils, climate, land use/land cover, water resources, topography, and potential natural vegetation (Figure 1).

northern_plains_mrlas_fig1.jpg (104683 bytes)

Figure 1. Northern Plains region physiography and MLRAs.


Diversity

The soil resource base is a good indicator of regional land resource diversity, which is considerable in this region. Together, more than 4,427 soil series and 48,165 soil map units represent the Northern Plains landscape (Waltman, 1995).

Climate regimes range from arid to humid, and soil temperature regimes extend from warm temperate to tundra and permafrost. Precipitation ranges from less than 6 inches (142mm) in the Bighorn Basin of Wyoming to 44 inches (1,110mm) in southeastern Kansas.

Topography ranges from elevations of 14,433 feet (4,500m) on Mt. Elbert, Colorado, to under 800 feet (213m) in Kansas. Elevation is below 4,920 feet (1500m) for over 70% of the region, and only 4% of the land area is higher than 9,000 feet (2,743m).


National Significance

USGS's Land Use and Land Cover Digital Data (1986) indicates that the Northern Plains region contains a significant proportion of the nation's basic resources. Although the region includes only 15% of the conterminous U.S., it contains:

  • 27% of the nation's cropland and pastures
  • 66% of the tundra and snowfields of the lower 48 states (These are areas of sensitive ecosystems and also significant sources of snowmelt water for the Missouri, Platte, Colorado, and Arkansas Rivers.)
  • nearly 33% of the nation's total rangeland
  • 17% of the nation's total farm and ranch production (crop and livestock)
  • almost 21% of U.S. livestock production.

The region's nearly 280,000 farms and ranches total 13% of the nation's farms, but they manage 28% of the U.S. farmland area. Less than 1% of the region is urban land, but this urban area makes up 5% of the nation's total urban land.


Soil Quality and Health

From 1982 to 1992 the National Resources Inventory (NRI) recorded a loss of 1.85 million acres of prime farmland in the region, or a 0.6% decrease in prime farmland.

Soil Fragility

About 23% (97 million acres) of cropland and rangeland in the Northern Plains has fragile soils with tolerable soil-loss levels of less than 3 tons per acre annually. About 43% of the rangelands are associated with fragile soils (Figure 2). Of the 64 million acres of forest lands, nearly 64% occur on fragile soils (Figure 3).

northern_plains_fragile_soils_map2.jpg (103552 bytes)

Figure 2. Rangelands with fragile soils in the Northern Plains region. By W.J. Waltman and B. Stephens, USDA, NRCS. Source: State Soil Geographic Database (Soil Survey Staff, 1994), Albers Equal Area Projection, Dec. 1995, Map Series No. 95-0017, Northern Plains GIS/Remote Sensing. Rangelands with fragile soils are derived from the State Soil Geographic Database and the 1:250000 Land Use and Land Cover Digital Data (USGS, 1986). Fragile soils are defined by tolerable (T) levels of erosion that are less than 3 tons/acre/year.

northern_plains_fragile_forest_soils_map3.JPG (109681 bytes)

Figure 3. Forest lands with fragile soils in the Northern Plains region. By W.J. Waltman and B. Stephens, USDA, NRCS. Source: State Soil Geographic Database (Soil Survey Staff, 1994), Albers Equal Area Projection, Dec. 1995, Map Series No. 95-0018, Northern Plains GIS/Remote Sensing. Forest lands with fragile soils are derived from the State Soil Geographic Database and the 1:250000 Land Use and Land Cover Digital Data (USGS, 1986). Fragile soils are defined by tolerable (T) levels of erosion that are less than 3 tons/acre/year.


Conservation Needs

The 1992 NRI shows a total of 68 million acres of cropland, forest land, and pastureland needing conservation treatment. Approximately 45% of the cropland and 35% of the pastureland need conservation treatment for either wind or water erosion.

An estimated 236 million tons of soil erode annually in Montana, Colorado, and Kansas, three of the five states nationally which have the most soil erosion. About 60 million acres of cropland, excluding Conservation Reserve Program (CRP) lands, are considered highly erodible for conservation compliance (Table 1; Figure 4). About 11 million acres of cropland are eroding at rates greater than tolerable levels (T) and, of these, 4 million acres are eroding at rates exceeding 2T.

Table 1. Highly Erodible Land (HEL) status and CRP acres in the Northern Plains region (CTIC, 1995).


Total Cropland (Acres Planted)

CRP (Acres)

HEL (Acres)

Percent CRP/HEL

Percent HEL Adequately Treated

Colorado

5,419,721

1,941,958

9,694,310

20.0

67%

Kansas

19,549,254

2,885,568

12,984,760

22.2

90

Montana

7,778,164

2,798,171

14,097,630

19.8

85

Nebraska

15,688,155

1,371,997

10,026,545

13.7

87

North Dakota

19,275,443

2,885,371

7,816,893

36.9

95

South Dakota

12,539,980

1,773,772

4,086,660

43.4

86

Wyoming

712,610

253,282

1,181,547

21.4

87

Totals

80,963,327

13,910,119

59,888,345

23.2

85

National Totals

283,916,794

34,773,012

147,805,122

23.5

75

northern_plains_crp_lands_map4.jpg (95415 bytes)

Figure 4. Distribution of Conservation Reserve Program (CRP) lands in the Northern Plains region. By W.J. Waltman and B. Stephens, USDA, NRCS. Source: National CRP Database, USDA/NRCS (1995), Albers Equal Area Projection, Dec. 1995, Map Series No. 95-0029, Northern Plains GIS/Remote Sensing. In the Northern Plains Region, CRP lands amounted to 14.7 million acres (6 million ha). The percent CRP lands derived from total croplands was derived for each county.


Erosion Rates

Producers carrying out conservation plans made significant progress in reducing sheet, rill, and wind erosion. Between 1982 and 1992, sheet and rill erosion decreased by 19% across the 110 million acres of cultivated cropland in the region, annually saving more than 53 million tons of topsoil.

Similarly, average annual wind erosion on rangeland decreased 7.5%, saving nearly 47 million tons of topsoil each year. Wind erosion on cultivated cropland decreased 30%.

These successes reflect a reduction of 25 million acres needing conservation measures.

Irrigation and Erosion

Irrigated cropland (Figure 5) increased by 468,000 acres during the period between 1982 and 1992. Gravity irrigation systems were used on over 6.3 million acres of the 13.6 million of irrigated cropland in 1992. Over 71% of these acres needed conservation treatment for irrigation-induced erosion.]

northern_plains_irrigated_lands_map5.jpg (106122 bytes)

Figure 5. Irrigated cropland 1992, Northern Plains region. USDA, NRCS, Lambert Conformal Conic Projection, 1927 North American Datum. Source: National Cartography and GIS Center, NRCS, USDA, Ft. Worth, TX, in cooperation with the natural Resources Inventory Division, NRCS, USDA, Washington, D.C., using GRASS/MAPGEN software, 09/95. Map based on data generated by NRI Division using 1992 NRI. Because the statistical variance in some of these areas may be large, the map reader should use this map to identify broad trends and avoid making highly localized interpretations.

Sprinkler irrigation systems were used on over 6.9 million acres, of which 60% needed conservation treatment.

An additional 395,000 acres were under a combination of sprinkler and gravity irrigation systems, and 68% of these acres also needed conservation treatment.

Conservation Tillage

Across the region, conservation tillage practices are applied to approximately 37% of annual crop acres (Table 2). Nebraska has shown the greatest adoption of conservation tillage practices, while Wyoming has shown the least.

Table 2. Conservation tillage management by state (CTIC, 1995)

Annual Crops Acres

No-Till Acres

%

Total Cons. Till Acres

Percent Cons. Tillage on Annual Crop Acres

Colorado

5,419,721

168,072

3.1

1,392,420

25.7

Kansas

19,549,254

1,070,559

5.5

5,823,364

29.8

Montana

7,778,164

463,114

6.0

2,929,710

37.7

Nebraska

15,688,155

2,486,892

15.9

9,018,701

57.5

North Dakota

19,275,443

910,794

4.7

6,148,002

31.9

South Dakota

12,539,980

1,371,533

10.9

4,649,369

37.1

Wyoming

712,610

5,900

.08

98,739

13.9

Totals

80,963,327

6,476,369

8.0

30,060,305

37.1

National Totals

283,916,794

38,985,494

13.0

99,327,006

35.0

Between 1989 and 1994, no-till expanded from 2.9 to 8.0% of total planted acres. Given the estimates of conservation tillage management in the region, considerable opportunity remains to encourage more adoption of conservation tillage.


Soil Salinity

Soil salinity is more widespread in the Northern Plains than anywhere else in the U.S. (Figure 6). Salinity adversely affects crop growth in the region's most northern states. Saline conditions in the root zone severely affect nearly 10% of Northern Plains landscapes.

northern_plains_soil_salinity_map6.jpg (100689 bytes)

Figure 6. Salinity-affected landscapes of the Northern Plains region. By W.J. Waltman and B. Stephens, USDA, NRCS. Source: R. Srinivasan (1995); Blackland Research Center, Texas Agric. Expt. Station, Temple, TX 76502, Albers Equal Area Projection, Dec. 1995, Map Series No. 95-0019, Northern Plains GIS/Remote Sensing. Soils and landscapes affected by salinity problems were derived from the State Soil Geographic Database (Soil Survey Staff, 1994). The areas of the saline-affected soils were based on the presence of a horizon with greater than 4dS/m. within 50 cm of the surface. The electrical conductivity estimates of the soils followed the saturated paste method of the Soil Survey Staff (1995).


Climate Change

Even small changes in climate affect soil health and agricultural production. Given CAST (Council for Agricultural Science and Technology; 1992) and OTA (Office for Technology Assessment; 1992) projections of 3.6 to 5.4°F (2 to 3°C) increases of mean annual air temperatures by the next century, climate change and its associated greater variability may have a significant impact on soil quality, crop management systems, and conservation practices across the Northern Plains.

Temperature

According to both CAST (1992) and OTA (1993), a 5.4°F (3°C) increase in mean annual air temperature (MAAT) can be projected for the region around the year 2030.

The Newhall Simulation Model (Van Wambeke et al., 1991), which was used to estimate shifts in soil temperature regime, indicates that a 5.4°F (3°C) increase in MAAT would shift the thermic regime (warm temperate) from Kansas to Nebraska and could remove tundra and permafrost regimes from the Rocky Mountains. Frigid soils would decrease from 16% of the region to 4%. The warm-phase (54-58°F; 12-14°C) of the mesic soil temperature regime would expand from 15 to 38% and thermic soils would expand from 6 to 21%.

Evapotranspiration and Growing-Degree Days

Associated with the temperature increase would be parallel increases in potential evapotranspiration and growing-degree days —13% and 36%, respectively.

Regionally, some geographic areas could benefit climatically, while the ecosystems of others could become unsustainable. Since 44% of the region has less than 2,000 growing-degree days, and 29% of the landscape has less than a 100-day frost-free period, an increase in MAAT may allow expansion of the winter wheat belt and corn belt.

Potential Effects of Changes

The period of 1931 to 1940 often has been used to illustrate the potential impacts of climate change in 2030. Statistics from 116 long-term weather stations in the Northern Plains therefore were compared to quantify the differences in climatic character between the "Dust Bowl" years and the "normal" years of 1961 to 1990.

Table 3 summarizes the climatic variability differences between the two periods. Notably, the mean air temperature across the region increased by only 1.7°F (~ 1°C) during the Dust Bowl years. But mean annual precipitation decreased by 15%.

Table 3. Comparison of climatic characteristics during the "Dust Bowl" years (1931 to 1940) with the 1961 to 1990 normals across the Northern Plains Region.

Climatic Parameter

1931 to 1940 Dust Bowl

1961 to 1990 normals

Number of long-term stations

116

116

Mean annual air temperature

48.4°F

46.7°F

Mean annual precipitation

415mm

491mm

Mean total growing-degree days (Base 50°F)

3,000 heat units

2,663 heat units

Mean frost-free period (consecutive days &GT 32°F)

139 days

134 days

Mean annual potential evapotranspiration (PET)

677mm

642mm

Growing season precipitation (April-September)

296mm

353mm

Mean annual moisture deficit (precipitation - PET)

-262mm

-151mm

Biological window at 5°C

55 days

89 days


Growing-degree days showed more change than frost-free period. The biological window (the time in cumulative days when soils are moist and warmer than 40°F [5°C], which quantitatively describes the period of soil microbial activity) decreased nearly 34 days during the Dust Bowl years.


Water Supply

Rainfall and snowmelt are the primary water sources in the mountains of the western Northern Plains region. Spring and early summer rains, local alluvial aquifers, and large regional aquifers, such as the High Plains or Ogallala and Big Sioux, are major water sources for the region's central and eastern plains (USGS, 1986).

However, the High Plains aquifer has been mined significantly, and recharge rates are not keeping pace with agricultural withdrawals. Areas of declining water levels coincide with areas of most rapid irrigation expansion (Figures 7 and 8).

Figure 7. Water level changes in the High Plains Aquifer, pre-development to 1980 (Weeks and Gutentag, 1981).

Figure 8. Water level changes in the High Plains Aquifer, 1980-1990 (after Dugan and Schild, 1992).


Surface waters, including the Missouri, Platte, Arkansas, and their tributaries, plus the High Plains Aquifer, are the major water sources for the west central, central, and eastern parts of the region. As one moves eastward, precipitation increases during the growing season, supplying most crop needs for most years in MLRAs 102A, 102B, 106, and 107. Surface waters and aquifers provide water for domestic needs.

Water supply issues will become increasingly important across the region as urban centers grow and as agricultural water uses, including irrigation, expand. Urban demands rose with an expanding population, and irrigation increased 2.7% (400,000 acres) from 1982 to 1992.

Roughly 18 million acres of cropland in the region are irrigated. Nebraska showed the largest gain (8.4%) in irrigation from 1982 to 1992, accounting for 41% of the irrigated cropland in the entire region. Colorado experienced the largest decrease (3.8%) among the seven states.

Currently, three-quarters of irrigated cropland is under cultivation. Most of the rest supports hay production. Agricultural uses of surface and groundwater account for 86% of total water withdrawals among the Northern Plains states.


Water Quality

The limited amount of water in the Northern Plains region heightens concerns about the quality of water for both sustained agricultural production and domestic uses.

Sedimentation, turbidity, pesticides, agricultural and urban waste, and fertilizer are the primary causes of surface and ground water quality problems. The threat to water quality by runoff from feedlots and other confined animal operations has increased with feedlot population increases, especially in the eastern part of the region.

Surface Water Quality

Agricultural activity is responsible for most of the polluted surface water in the region, including rivers, streams, lakes, and reservoirs (USEPA, 1990).

Table 4 compares surface water quality in the Northern Plains with surface water quality nationally. Siltation of stream beds from accelerated soil erosion, nutrient loading (primarily nitrogen and phosphorus), and pathogens from urban and agricultural waste are the primary causes of the region's surface water quality impairment. The somewhat generic term "organic enrichment," which Table 4 uses, refers to the eutrophication effects of runoff, containing nutrients from agriculture and domestic waste and applied fertilizer, when that runoff enters local and regional surface waters.

Table 4. Surface water quality summary for the Northern Plains states and nationwide.

Fully supporting1
designated use

Cause of impairment2

Rivers and Streams

Sediment

Nutrients

Pathogens of Impairment

Agriculture as Impairment

Nationwide

70%

42%

27%

19%

55%

Northern Plains

60%

54%

39%

32%

77%

Lakes and Reservoirs

Nutrients

Sediment

Organic Enrichment

Agriculture as Impairment

Nationwide

74%

49%

25%

25%

58%

Northern Plains

81%

55%

41%

-

60%

Source: US Environmental Protection Agency, 1990.
1
Percentage of assessed water. Of the nation's total, the survey assessed 29% of river and stream mileage and 41% of lake and reservoir area.
2 The leading three causes of impairment are listed. The percentage refers to the fraction of impaired stream miles or lake area affected by the cause indicated. Since any given stream mile or lake area may be affected by multiple causes, the percentages need not sum to 100%.


Soil erosion data can provide indicators of surface water quality. Eroded soil that reaches stream courses is detrimental to water quality through the combined effects of siltation and nutrient loading. Erosion rates from croplands in the Northern Plains are about 25% higher than for areas outside the region (Figure 9). Notably, however, erosion in the Northern Plains is dominated by wind action, which probably has a greater impact on soil fertility than on off-site surface water quality.


Figure 9. Comparison of Northern Plains region and national erosion rates (USDA/NRCS, 1994).


Groundwater Quality

Groundwater quality in the Northern Plains also affects domestic health and agricultural uses of water. Generally, shallow alluvial aquifers in the eastern portions of the region and along major drainage systems are the most vulnerable to contamination.

The region's major groundwater quality concerns are salinity and contamination of the shallow alluvial aquifers from nitrates and pesticides. The contamination level in these aquifers directly relates to the soils' leaching potential, the amount of water available for deep percolation, pesticide solubility, and nitrate availability.

Fertilizer and pesticide leaching is a primary threat to the region's groundwater quality. Fertilizer and pesticide applications have increased significantly since 1965, and they are potential sources of pollution.

Madison and Burnett (1985) showed elevated nitrate-N (less than 3 parts per million [ppm]; assumed background level) concentrations in groundwater across most of Kansas and the western part of the corn belt (Figure 10). Later, Spalding and Exner (1991) illustrated nitrate-nitrogen concentrations greater than 10 ppm along the Central Platte River. Hatfield et al. (1993) reported that at least 480,000 acres (200,000 hectares) in the Platte River Valley between Kearney and Columbus are underlain by groundwater having NO3-N concentrations greater than 10 ppm.

Figure 10. Distribution of Nitrate-N concentrations in groundwater in the contiguous United States (Madison and Burnett, 1985).


The contaminated area is expanding by more than 9,600 acres/year (4,000 ha/year) (Hatfield et al., 1993). The contaminated areas were characterized by irrigated corn monoculture on well to excessively well drained soils with a vadose zone less than 49 feet (15m) thick.


Grazing Lands

Rangeland in the Northern Plains region comprises 43% of the landscape and is nearly one-third of all rangeland in the conterminous U.S. Of the total acreage of rangeland in the region (180 million acres), 26% is associated with soils of high wind erosion potential, and over 40% occurs in association with fragile soils (T < 3 tons/acre/year; T=Tolerance).

This rangeland helps support about 23 million head of cattle in the region, or 24% of the U.S. cattle population (Figure 11), and 3 million head of sheep, about 32% of the U.S. sheep population (National Agricultural Statistics Service, 1995). Many wildlife species also depend on rangeland habitat.

Figure 11. Breakdown of cattle numbers in the Northern Plains (NASS, 1995).


Of the 180 million acres of rangeland in the Northern Plains, 157 million acres are privately owned. The private rangeland includes 4 million acres of wetland identified by using the Cowardin Classification System (NRI, 1995).

Pastureland in the Northern Plains comprises 3% of the landscape, with 13 million acres privately owned. Soil loss on pastureland generally is very low, and at present no standard methods exist for evaluating its condition, quality, or health (Figure 12).

Figure 12. Tons per acre of soil loss by land use in the Northern Plains (USDA/NRCS, 1994).


Range condition data show that 71 million acres of rangeland in the Northern Plains are in poor and fair condition. This indicates a loss of higher successional plants in the plant community, which can result in loss of wildlife habitat, increased water runoff with increased soil erosion, increased soil loss from wind erosion, loss of species diversity, and decreased productivity.

Rangeland apparent quality or condition data for 1982 and 1992 show a 9% increase of rangeland with a worsening (negative) condition and only a 2% increase of rangeland with an improving (positive) condition (Figures 13 and 14). Thus, some rangeland plant communities are slowly losing quality or moving toward nonsustainability.

Figure 13. Range condition classes by acres in the Northern Plains (USDA/NRCS, 1994).

Figure 14. Acres of apparent trend on rangeland in the Northern Plains (USDA/NRCS, 1994).


The 1992 NRI data show that 98 million acres (62.5%) of rangeland in the Northern Plains need conservation treatment in three major categories. Grazing management (controlling/managing the grazing animals) to improve the plant community is needed on 53% of the rangeland; erosion control is needed on 26%, mostly for wind erosion occurring in Wyoming and Colorado (Figure 15); and weed or brush control is needed on 8%.

northern_plains_wind_erosion_map10_fig15.jpg (110826 bytes)

Figure 15. Rangeland soils with high potential for wind erosion in the northern Plains region. By W.J. Waltman and B. Stephens, USDA, NRCS. Source: R. Srinivasan (1995); Blackland Research Center, Texas Agric. Expt. Station, Temple, TX 76502, Albers Equal Area Projection, Dec. 1995, Map Series No. 95-0027, Northern Plains GIS/Remote Sensing. Rangeland soils with high potential for wind erosion were derived from wind erodibility group 1 to 3 in the State Soil Geographic Database (STATSGO; Soil Survey Staff, 1994). Rangelands were derived from the USG 1:250000 Land Use and Land Cover Digital Data (USGS, 1986).


A significant noxious weed problem also appears to exist in some of the northernmost Northern Plains states. The main two noxious weeds are leafy spurge and spotted knapweed, but data are not readily available for monitoring the spatial extent of the problem.


Forest Lands and Windbreaks

Forest land makes up 15% of the Northern Plains region; however, only about 3% is privately owned. Private forest land decreased 1.6% between 1982 and 1992 (NRI, 1995). Colorado landscapes accounted for 76% of the forest land losses.

Timberland forest land capable of producing crops of industrial wood— on all ownerships in the region declined by 9% from 1952 to 1987 (Powell et al., 1992). Much of the loss is due to clearing for agriculture and to flooding low areas for dam construction. Private timberland is about 36% of the total timberland in the region and closer to 70% outside the Rocky Mountain portion of the region (Powell et al., 1992).

Since the reduction in timber harvests on public lands in the West, pressure to harvest the ponderosa pine on nonindustrial private forest land in eastern Montana and adjoining states has increased. Typically, limited forestry technical assistance is available in these areas, and this constrains resource management considerations during and after harvest.

About 70% of the nation's windbreaks grow on private lands in the Northern Plains region (1987 NRI). However, advancing age and numerous environmental stresses are increasing the need to rejuvenate this resource.

Windbreaks protect approximately 255,000 farmsteads, thus reducing energy consumption in buildings and improving the health and vigor of livestock. Approximately 86,000 miles of field windbreaks protect about 4 million acres of agricultural land, resulting in less wind erosion and improved crop quantity and quality. They are a substantial resource, but field windbreaks protect only about 3% of the region's cropland (Brandle et al., 1992). Windbreaks protect about 42% of the region's farmsteads (Brandle et al., 1992).


Wetlands

Wetland is an important component of the landscape and ecosystems of the Northern Plains region. Wetlands provide floodwater conveyance and retention, offer groundwater recharge and discharge, and trap sediment, nutrients, and pesticides. They play a critical role as habitat for waterfowl, shore birds, mammals, invertebrates, insects, and plants.

The Northern Plains contains about 10% of the nation's wetlands. The 1992 National Resources Inventory (NRI) estimates that nearly 15.5 million acres of wetland are on nonfederal lands in the region. These wetlands are 4.6% of the region's total nonfederal lands. Overall, a weak but net increase (0.3%) of inventoried wetland occurred between 1982 and 1992. Only North Dakota showed a net loss (14,700 acres).

Approximately 2.2 million wetland acres are associated with cultivated cropland. Sixty-four percent (10 million acres) of the region's wetlands are in North Dakota, South Dakota, and Montana and are associated largely with the "prairie pothole" region.

The Northern Plains region has approximately 7.5 million acres of wetland subject to the 1985 Food Security Act (FSA) swampbuster regulations. Seventy-three percent (5.4 million acres) of those FSA wetlands are in North Dakota, South Dakota, and Nebraska.

The 1992 NRI net increase in wetland suggests significant progress has occurred in stabilizing wetlands, given that wetland losses between 30 and 50% occurred from 1780 to the 1980s (Dahl et al., 1991). The wetland stability estimate has been attributed primarily to wetland protection and enhancement programs administered by federal, state, and local agencies and by private organizations over the past 10 years.


Economics

Population

The region's population in 1994 was estimated at 10.5 million people, about 4% of the U.S. population. Fifty-nine percent of the region's population resides in the two southernmost states, Colorado and Kansas. Colorado's population has nearly doubled since 1960, while other states have shown relatively slow growth.

The region's population is primarily white (86%), followed by Hispanics (6%) and Blacks (3%). The region also is the home of approximately 196,000 American Indians, who manage and own nearly 16 million acres of land —almost 28% of the Indian lands in the U.S. and about 4% of the Northern Plains. According to the 1990 Census, the region's American Indian population has grown 29% since 1980.

Settlement Changes

Many counties in the Northern Plains region reached their greatest population in the 1890s. During the last century, many rural areas and towns under 10,000 lost population to regional towns. Many small counties have reached the crisis point of sharing local and county government in regional complexes. Rural county economies and governments are becoming unsustainable in much of the drier High Plains.

Figure 16 shows the population density pattern of the region in 1986. Outmigration in western North and South Dakota and eastern Montana is expected, where regional centers fail to develop, into the next century.

Figure 16. Population density in the Northern Plains (U.S. Dept. of Commerce, 1993).


In the 1980s, while the remote counties lost their sustainable population levels, population in the regional centers grew. Tourism in the mountain areas became a larger economic sector than agriculture. The mountain areas also gained population from retirees, which translates into land ownership of smaller parcels, changing land use, and higher land values.

Per Capita Income

The economy of the Northern Plains, like the population, is highly localized into metropolitan regions. Denver's population and economy are far greater than those of rural Colorado, the western Dakotas, Montana, and Wyoming. The per capita income on a county basis (Figure 17) is more evenly concentrated than the population density (Figure 16).

Figure 17. Northern Plains per capita income by county. The US average income was $18,696 in 1990 (U.S. Dept of Commerce, 1994).


Most areas of the region have low per capita incomes, but the region includes both the richest and the poorest counties in the country. Denver makes Colorado the only state in the region with a per capita income higher than the national average. During good years, a few thinly populated farm counties have some of the highest per capita incomes in the country. The counties with American Indian reservations have the lowest per capita incomes in the country.

Agricultural Systems

Nine distinct agricultural systems operate in the Northern Plains region. Sommers and Hines (1991) applied cluster analysis to the Census of Agriculture, defining 12 clusters that reveal patterns of agricultural production and diversity for the United States. The cattle-wheat-sorghum cluster comprised 49% of the Northern Plains region.

Market output per county follows the precipitation patterns of the region. The eastern border counties share the highly productive systems of the Corn Belt and Red River Valley, and this farming pattern needs more labor and inputs per acre. The larger towns in these counties also are large enough to generate small industrial and commercial growth.

The basic farm size increases east to west along the decreasing precipitation gradient. Westward, agriculture changes to a flexible, mixed cropping rotation, then to winter wheat/fallow, and finally to grazing, requiring less labor and inputs per acre than the more humid east.

Farming Changes

Farms in the Northern Plains region are undergoing major changes in the 1990s, particularly with changes in conservation programs and culture.

Wheat acreages and production are expected to increase through the 1990s, at the expense of grass and hay acreage. The corn/soybean belt is expanding. The increasing number of irrigated acres, such as those in Nebraska, are going into corn production, with soybeans as the rotational crop. This increase in irrigated corn production correlates strongly with increases in fertilizer and herbicide use.

Farms in the region are huge and getting larger, while the number of farms and ranches in the region is slowly decreasing. Between 1982 and 1992, the NRI (1994) showed a 10% decrease, from 266,679 to 240,070 farms. Larger feedlots also are replacing diversified farming operations.


Regional Monitoring and Research Infrastructure

Three of the National Science Foundation's Long-Term Ecological Research Sites (LTERS) are in the Northern Plains region —the Konza Prairie (KS), Central Plains (CO), and Niwot Ridge (CO) sites, which focus on range and alpine ecosystems. These LTERS serve as benchmarks for ecosystem and global change monitoring.

Glacier, Yellowstone, and Rocky Mountain National Parks are recognized as UNESCO Biosphere Reserves. They serve as benchmark locations for biodiversity and global change monitoring in the Northern Plains region. In addition, more than 70 agricultural research stations and farms, representative of most agricultural MLRAs, are located across the Northern Plains.

Research and collaboration from these sites will provide valuable insights on natural resource conditions and trends into the next century.


Conclusion

The NRCS recognizes that the Northern Plains region is a land of extremes in soils, climate, crops, and animal agriculture. Northern Plains farmers and ranchers have made substantial progress in soil and water conservation since the 1930s and especially in the past ten years, as documented by the 1992 National Resources Inventory.

The agricultural community's progress in reducing wind and water erosion on croplands and rangelands often has exceeded the national norms. The stabilization of and net gains of wetlands over the past ten years are significant accomplishments (especially since the national trend was slightly negative) and have improved wildlife populations, increased flood storage capacity, and contributed to carbon sequestration.

Similarly, the 14.7 million acres of land submitted to the Conservation Reserve Program contributed to successes in maintaining wildlife populations, reducing wind and water erosion, and supporting carbon sequestration in Great Plains soils. Furthermore, these accomplishments occurred during a period of greater climatic variability and stress, including such events as the "Drought of 1988."

However, more than 130,000 acres of CRP lands were released in 1995. The importance of CRP will not be apparent until the region experiences another extended drought analogous to that of the Dust Bowl years. With 97 million acres of fragile soils in the region, the natural and agroecosystems have little capacity to adapt to a changing environment.

Soil quality and health issues in the region require more extensive evaluation than currently possible through the NRI or soil survey process. Saline seep development, alkalinity, carbon storage, and wind erosion are dominant soil quality concerns. Over the longer term, how will these soils and landscapes respond, physically and chemically, to climate changes?

Water quality problems are well recognized in the region, particularly along the major drainages where irrigated corn monoculture occurs in association with soils of high leaching potential. The Central Platte River reach may serve as a good barometer for progress in reducing nitrate and atrazine levels in groundwater.

The decrease in forests on nonfederal lands, although minor in extent, may be signaling movement of timber harvesting from federal lands. The Northern Plains region also has a large hidden infrastructure across the landscape —windbreaks. Since 70 to 80% of the windbreaks need some type of renovation to maintain their function, the past successes recorded across the region in reducing wind erosion may be at risk. With the initiation of the Wetlands Reserve Program, wooded riparian corridors should expand and are hoped will offset CRP releases.

Rapid urban growth along the Colorado Front Range, and increasing irrigation demands, particularly in Nebraska, are reducing downstream flows and depleting major aquifers in the Northern Plains region. The NRCS SNOTEL stations in the headwaters will become increasingly important for forecasting water supply, particularly under an uncertain climate.

Paralleling water supply issues, the loss of prime farmlands —which are the soils with the best set of physical properties for soil moisture retention— will become increasingly important in periods of high climatic variability. The regional research and monitoring framework will improve our land resource and climate databases and provide important information for natural resource analysis.

References

Andersen, J.R., E.E. Hardy, J.T. Roach, and R.E. Witmer.1976.A land use and land cover classification system for use with remote sensor data. U.S. Geological Survey Paper 964, 28 p.
Brandle, J.R., T.D. Wardle, and G.F. Bratton. 1992. Opportunities to increase tree planting in shelterbelts and the potential impacts on carbon storage and conservation. In Sampson, R.N. and D. Hair (eds.), Forests and Global Change Volume One: Opportunities for Increasing Forest Cover, pp 157-176. American Forests, Washington, D.C.
Bratton, G.F., P. R. Schaefer, and J. R. Brandle. 1993. Conservation forestry for sustainable Great Plains ecosystems. In Conservation of Great Plains Ecosystems: Current Science, Future Options. Kansas City, MO, April 7-9, 1993.
Buol, S.W., P.A. Souchez, S.B. Weed, and J.M. Kimble. 1990. Predicted impact of climatic warming on soil properties and use. In Impact of Carbon Dioxide, Trace Gases, and Climate Change on Global Agriculture, ASA Special Publication No. 53, American Soc. of Agronomy, Madison, WI.
Cole. C V.. J.W.B. Stewart, D.S. Ojima. W.J. Parton, and D.S. Schimel. 1989. Modelling land use effects of soil organic matter dynamics in the North American Plains. In Ecology of Arable Land. M. Clarholm and L. Bergstrom (eds.), pp. 8998. Kluwer Academic Publications.
Conservation Technology Information Center (CTIC). 1995. 1995 National crop residue management survey. West Lafayette, IN.
Council for Agricultural Science and Technology (CAST). 1992. Preparing U.S. agriculture for global climate change. Task Force Report No. 119, Ames, IA.
Elliot, E.T., H.H. Franzen, C.A. Campbell, C.V. Cole, and R.J.K. Myers. Principles of ecosystem analysis and their application to integrated nutrient management and assessment of sustainability. In Sustainable land management for the 21st Century. Vol.2: Plenary Papers, Proceedings of the International Workshop on Sustainable Land Management for the 21st Century, pp.35-57, Lethbridge, Canada, June 20-26, 1993.
Elliott, E.T., K. Paustian, and C.V. Cole. 1994. Regional projections of C dynamics with global change in the central United States: interactive effects of management, climate, and elevated CO2. Annual Report, National Inst. for Global Environmental Change, Univ. of California, Davis, CA.
Garrett, H.E., L.E. Buck, M.A. Gold, L.H. Hardesty, W.B. Kurtz, J.P. Lassoie, H.A. Pearson, and J.P. Slusher. 1994. Agroforestry: An integrated land-use management system for production and farmland conservation. A Comprehensive Assessment of U.S. Agroforestry prepared for the USDA SCS. 58 p.
Gebhart, D.L., H.B. Johnson, H.S. Mayeux, and H.W. Polley. 1994. The CRP increases soil organic soil. Journal of Soil and Water Conservation 49(5):488-492.
Kellogg, R.L., M.S. Maizel, and D.W. Goss. 1992. Agricultural chemical use and ground water quality: where are the potential problem areas? USDA Soil Conservation Service, Economic Research Service, Cooperative States Research Service, and the National Center for Resource Innovations. Washington. D.C.
Korte P.A.. and L.H. Fredickson. 1977. Loss of Missouri's lowland hardwood ecosystem. Trans. of the 42nd North American Wildlife and Natural Resources Conference, Wildlife Management Institute, Washington, D.C.
Lindstrom, M.J., T.E. Schumacher, and M.L. Blecha. 1994. Management considerations for returning CRP lands to crop production. Journal of Soil and Water Conservation 49(5):420-425.
Loveland, T.R., J.W. Merchant, D.O. Ohlen, and J.F. Brown. 1991. Development of a land and cover characteristics database for the conterminous U.S. Photogrammetric Engineering and Remote Sensing, Vol. 57(11):1453-1463.
Lyon, D.J., and J.W. Doran. 1995. Effects of long-term tillage in a winter wheat-fallow system on soil quality. Abstracts of the Converting CRP-Land to Cropland and Grazing Conservation Technologies for the Transition Conference. Soil and Water Conservation Society, Lincoln, NE.
Majumdar, S.K., L.S. Kalkstein, E.W. Miller, and L.M. Rosenfield. 1992. Global climate change: implications, challenges, and mitigation measures. The Pennsylvania Academy of Science, Easton, PA 18402.
Osborne, L. L., and M.J. Wiley. 1988. Empirical relationships between land use/cover and stream water quality in an agricultural watershed. J. Envir. Management 26:9-27.
Peterson, G.A., and C.V. Cole. Productivity of Great Plains soils: past, present, and future. Natural Resource Ecology Laboratory, Colorado State University, Ft. Collins, Colorado.
Powell, D.S., J.L. Faulkner, D.R. Darr, Z. Zhu, and D.W. MacCleery. 1993. Forest resources of the United States, 1992. USDA Forest Service Gen. Tech. Rep. RM-234. 132p.
Potash and Phosphate Institute. 1990. Soil test summaries: phosphorus, potassium, and pH. Better Crops with Plant Food 74(2):16-18.
Rosek, M.J., J.C. Gardner, D.L. Allen, M. Alms, D.F. Bezdicek, D.R. Huggins, D.L. Karlen, B.S. Miller, and M.L. Staben. 1995. Soil quality changes in response to the Conservation Reserve Program. Abstracts of the Converting CRP-Land to Cropland and Grazing Conservation Technologies for the Transition Conference. Soil and Water Conservation Society, Lincoln, NE.
Schertz, D.L. 1995. Post-CRP land use information needed by action agencies. Abstracts of the Converting CRP-Land to Cropland and Grazing Conservation Technologies for the Transition Conference. Soil and Water Conservation Society, Lincoln, NE.
Seevers, K. 1994. Morphological and chemical changes in Moody and Hastings soils after 30 to 35 years of cultivation. Masters Thesis, Dept. of Agronomy, University of Nebraska, Lincoln, NE.
Shaefer, P.R., and J.J.Ball. 1995. Present status and future potential for agroforestry in the Northern Great Plains. Proceedings, Agroforestry and Sustainable Systems Symposium, 1994, August 7-10, Fort Collins, CO. USDA Forest Service General Tech. Rep. RM-GTR-261 pages 115-125.
Sinclair, H.R. 1995. SRPG calculation summary. National Soil Survey Center, Lincoln, NE. p. 24.
Sinclair, H.R., and H. Terpstra. 1995. Soil ratings for plant growth. Iowa State University Statistical Laboratory. Ames, Iowa.
Soil Survey Staff. 1981. Land Resource Regions and Major Land Resource Areas of the U.S. USDA Handbook 296 and map (revised 1984).
Soil Survey Staff. 1994a. Colorado State Soil Geographic Data Base (CO-STATSGO). USDA-Natural Resources Conservation Service. Lakewood, CO. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994b. Kansas State Soil Geographic Data Base (KS-STATSGO). USDA-Natural Resources Conservation Service. Salina, KS. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994c. Montana State Soil Geographic Data Base (MT-STATSGO). USDA-Natural Resources Conservation Service. Bozeman, MT. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994d. Nebraska State Soil Geographic Data Base (NE-STATSGO). USDA-Natural Resources Conservation Service. Lincoln, NE. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994e. North Dakota State Soil Geographic Data Base (ND-STATSGO). USDA-Natural Resources Conservation Service. Bismarck, ND. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994f South Dakota State Soil Geographic Data Base (SD-STATSGO). USDA-Natural Resources Conservation Service. Huron, SD. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1994g. Wyoming State Soil Geographic Data Base (WY-STATSGO). USDA-Natural Resources Conservation Service. Casper, WY. Digital Soil Map and Attribute Data Base on CD-ROM.
Soil Survey Staff. 1995. Soil survey laboratory information manual. Soil Survey Investigations Report No. 45. USDA Natural Resources Conservation Service, National Soil Survey Center, Soil Survey Laboratory, Lincoln, NE.
Sommer, J.E., and F.K. Hines. 1991. Diversity in U.S. Agriculture: A new delineation by farming characteristics. Report No. 646, Agriculture and Rural Economy Division, Economic Research Service, U.S. Department of Agriculture.
Spalding, R.F., and M.E. Exner. 1991. Nitrate contamination in the contiguous United States. In Series G: Ecological Sciences, I. Bogundi and R.D. Kuzelka (eds.), NATO ASI Series, Vol. G30.
Srinivasan, R., J.G. Arnold, R.S. Muttiah, and P.T. Dyke. 1995. Plant and hydrologic simulation for the conterminous U.S. using SWAT and GIS. In press. Blackland Research Center, Texas A and M University System, Temple, TX.
Srinivasan, R. 1995. Digital datasets from the HUMUS Project. Blackland Research Center, Texas A and M University System, Temple, TX.
USDA National Agricultural Statistics Service (NASS). 1995a. Hogs and pigs: final estimates for 1988-1992. Agricultural Statistics Board Statistical Bulletin No. 904. Washington, DC
USDA National Agricultural Statistics Service (NASS). 1995b. Cattle on feed: final estimates for 1988-1992. Agricultural Statistics Board Statistical Bulletin No. 905. Washington, DC.
USDA National Agricultural Statistics Service (NASS). 1995c. Sheep and goats: final estimates for inventory of 1989-1993. Agricultural Statistics Board Statistical Bulletin No. 906, Washington, DC.
U. S. Bureau of the Census. 1994. USA Counties 1994, a Statistical Abstract Supplement on CD-ROM. U.S. Department of Commerce. Economics and Statistics Administration.
U.S. Bureau of the Census. 1992. 1992 Census of Agriculture on CD-ROM. U.S. Department of Commerce, Economics and Statistics Administration.
U.S. Bureau of the Census. 1990. Selected social and population characteristics. Department of Commerce, Washington, D.C.
USDA Soil Conservation Service. 1981. Land resource regions and major land resource areas of the United States. Agric. Handbook 296. U.S. Gov't Printing Office, Washington, DC.
U.S. Congress, Office of Technology Assessment. 1993. Preparing for an uncertain climate. Vol. I & II.
U.S. Department of Commerce. 1987. Census of Agriculture. U.S. Gov't Printing Office, Washington, D.C.
U.S. Department of Commerce. 1989. Census of Agriculture. U.S. Gov't Printing Office, Washington, D.C.
U.S. Department of Commerce. 1993. Census of Agriculture. U.S. Gov't Printing Office, Washington, D.C.
USDA Natural Resources Conservation Service. 1987. National Resources Inventory (NRI). Unpublished data tables on Windbreaks.
USDA Natural Resources Conservation Service. 1994. Summary Report 1992 National Resources Inventory. Iowa State University Statistical Laboratory, Ames, IA.
USDI Bureau of Indian Affairs. 1993. Indian service population and labor force estimates. Washington, D.C.
USDI Bureau of Indian Affairs. 1995. U.S. Reservation boundaries. Arc Export Format. Geographic Data Service Center, Lakewood, CO.
U.S. Environmental Protection Agency. 1990. National survey of pesticides in drinking water wells, Phase I report. Washington, D.C.
U.S. Geological Survey. 1986. Land use and land cover digital data from 1:250,000- and 1:1,100,000-scale maps. USGS Data User's Guide No. 4, Reston, VA.
Waltman, S.W. 1995. Queries from the Pre-release National Map Unit Interpretation Record (MUIR). National collection of digital detailed soil survey attribute data sets on CDROM. Lincoln, NE.


Appendix A

(MFS notes: "Appendix A" is a listing of related programs. These are generally NRCS and state programs. Please see the original text for this listing. Works of several of the cited authors are available on the "Sustainability Authors" page here.)
______
* America's Northern Plains: An Overview and Assessment of Natural Resources. August 15, 1997.
U.S. Dept. of Agriculture, Natural Resources Conservation Service.
See at Northern Prairie Wildlife Research, Jamestown, ND
< http://www.npwrc.usgs.gov/resource/othrdata/amnorpln/amnorpln.htm >
Written copies of the study are available at:
Strategic Planner
NRCS, Northern Plains Regional Office
Federal Building, Room 240
100 Centennial Mall North
Lincoln, NE 68508-3866

Home ]
 

Please send mail to webmaster@mnforsustain.org with questions or comments about this web site. Minnesotans For Sustainability (MFS) is not affiliated with any government body, private, or corporate entity. Copyright © 2002, 2003, 2004 Minnesotans For Sustainability