HomeMy WebLinkAbout981572.tiff soil survey of
Weld County, Colorado
Northern Part
United States Department of Agriculture
Soil Conservation Service and Forest Service
in cooperation with
Colorado Agricultural Experiment Station
EXHIBIT
981572
2 Soil survey
climate competition for forage started to be a problem. The
homestead acts of the late 1800's and early 1900's
Prepared by the National Climatic Center, Asheville. North Carolina brought in more and more farmers, and by 1913 about
The survey area generally is warm in summer and has 35 percent of the area had been converted to cropland.
freqent hot days. In winter, periods of very cold weather The drought and depression of the 1930's caused a
occur as a result of Arctic air moving in from the north or decline in the number of small cultivated farms. Farmers
northeast; however, milder periods occur when westerly could no longer make a living from small holdings
winds are warmed as they move downslope. Most managed for intensive cash crops. Many farmers left the
precipitation falls as rain during the warmer part of the area. The Bankhead-Jones Farm Tenant Act, passed in
year and normally is heaviest late in spring and early in 1937, was a repurchase law designed to aid the
summer. Winter snowstorms are frequent, but snow resettlement of farmers, to convert submarginal cropland
cover commonly disappears during milder periods. back to grassland, to help stabilize the economy, and to
In winter, the average temperature is 29 degrees F assist those who chose to stay.
and the average daily minimum temperature is 14 The Soil Conservation Service administered the
degrees. The lowest temperature on record, which purchase units as land utilization projects from 1938 to
occurred at Greeley on February 1, 1951, is -39 degrees. 1954. The land was then transferred to the Forest
In summer, the average temperature is 70 degrees and Service. Studies of the land were made, and in 1960 the
the average daily maximum temperature is 87 degrees. areas of rangeland suitable for permanent retention were
The highest recorded temperature, which occurred at Ft. designated as national grasslands. The grasslands
Lupton on June 23, 1954, is 108 degrees. - became a part of the national forest system. In 1961 the
The total annual precipitation is 12 inches. Of this, 9 grassland in the survey area was designated Pawnee
inches, or 75 percent, usually falls in April through National Grassland.
September, which includes the growing season for most Presently, about 10,000 cattle graze the public land of
crops. In 2 years out of 10, the rainfall in April through the Pawnee National Grassland, which facilitates the
September is less than 6.5 inches. The heaviest 1-day total management and enhances the economy of the
rainfall during the period of record was 3.2 inches at area. The objective of management of national
Greeley on June 8, 1974. Thunderstorms occur on about grasslands is to develop and execute conservation and
41 days each year, and most occur in summer. utilization programs for all renewable resources in
The average seasonal snowfall is 40 inches. The national grassland areas; this, to the extent feasible,
greatest snow depth at any one time during the period of promotes the integration of the federally administered
record was 30 inches. On an average of 18 days, at
least 1 inch of snow is on the ground. The number of land with the associated private and other public lands
such days varies greatly from year to year. into natural management units, which favors the
The average relative humidity in midafternoon is about development of sound land conservation and utilization
40 percent. Humidity is higher at night, and the average practices. Cattle use the forage about 5 months out of
at dawn is about 69 percent. The sun shines 71 percent the year.
of the time possible in summer and 70 percent in winter. The federal land is open to hunting that is subject to
The prevailing wind is from the south. Average state laws and regulations. Wildlife in this grassland area
windspeed is highest, 10.4 miles per hour, in April. includes antelope, a few deer, some coyotes, and
In some years during winter, a blizzard with high winds rabbits. A few prairie dog towns are scattered throughout
and drifting snow occurs in the survey area and snow the area.
remains on the ground for many weeks. In some years One of the main recreational uses of the area is bird
during summer, hailstorms cause severe damage to watching. The grassland supports large numbers of birds
crops in the area. of many species, especially during migrations. The area
is known internationally as an excellent study area for
Pawnee National Grassland birds of prey, and it has good breeding populations of
unique high plains species such as mountain plover,
By Steward J. Adams, district ranger, Forest Service. burrowing owl, McCowan's longspur, and chestnut-
The Pawnee National Grassland (see map at the back collared longspur. Hikers also use areas of the
of this publication) is one of 19 national grasslands in grassland, although there are no special hiking trails.
the western United States. Most of the Pawnee National Crow Valley Park is one-fourth mile north of the town
Grassland is flat to rolling prairie grassland intermingled of Briggsdale. The park is located among shade trees
with privately owned farmland and grassland. along Crow Creek. Picnic and camping areas are in the
The national grasslands were started as part of an park. The campground is closed in winter.
economic program. The land originally was settled by Additional information on the Pawnee National
stockmen whose ranches covered vast areas of the Grassland can be obtained from the local office of the
plains. During the late 1800's, overgrazing and Forest Service.
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index to soil map units
1—Altvan fine sandy loam, 0 to 6 percent slopes 11 38—Nucla loam, 0 to 3 percent slopes 30
2—Altvan fine sandy loam, 6 to 9 percent slopes 12 39—Nucla loam, 3 to 9 percent slopes 30
3—Argiustolls-Rock outcrop complex, 0 to 9 percent 40—Nunn loam, 0 to 6 percent slopes 31
slopes 12 41—Nunn clay loam, 0 to 6 percent slopes 31
4—Ascalon fine sandy loam, 0 to 6 percent slopes... 13 42—Olney loamy sand, 0 to 3 percent slopes 31
5—Ascalon fine sandy loam, 6 to 9 percent slopes... 13 43—Olney loamy sand, 3 to 9 percent slopes 32
6—Ascalon-Blakeland complex, 3 to 15 percent 44—Olney fine sandy loam, 0 to 6 percent slopes 32
slopes 13 45—Olney fine sandy loam, 6 to 9 percent slopes 33
7—Ascalon-Bushman-Curabith complex, 0 to 3 46—Otero sandy loam, 0 to 3 percent slopes 33
percent slopes 14 47—Otero sandy loam, 3 to 9 percent slopes 34
8—Ascalon-Bushman-Curabith complex, 3 to 15 48—Otero-Tassel complex, 6 to 30 percent slopes 34
percent slopes 15 49—Paoli fine sandy loam, 0 to 6 percent slopes 35
9—Avar fine sandy loam 16 50—Paoli fine sandy loam, 6 to 9 percent slopes 36
10—Avar-Manzanola complex, 0 to 3 percent slopes 16 51—Peetz gravelly sandy loam, 5 to 20 percent
11—Badland 17 slopes 36
12—Bankard loamy fine sand, 0 to 3 percent slopes 17 52—Peetz-Altvan complex, 0 to 20 percent slopes 36
13—Blakeland loamy sand, 0 to 6 percent slopes 17 53—Peetz-Rock outcrop complex, 9 to 40 percent
14—Blakeland loamy sand, 6 to 12 percent slopes... 18 slopes 37
15—Bresser sandy loam, 0 to 3 percent slopes 18 54—Platner loam, 0 to 3 percent slopes 38
16—Bresser sandy loam, 3 to 9 percent slopes 19 55—Renohill fine sandy loam, 0 to 6 percent slopes 38
17—Bushman fine sandy loam, 0 to 3 percent 56—Renohill fine sandy loam, 6 to 9 percent slopes 39
slopes 19 57—Renohill-Shingle complex, 3 to 9 percent slopes 39
18—Bushman fine sandy loam, 3 to 9 percent 58—Rosebud fine sandy loam, 0 to 6 percent
slopes 19 slopes 40
19—Bushman-Curabith-Canyon complex, 0 to 20 59—Rosebud fine sandy loam, 6 to 9 percent
percent slopes 20 slopes 40
20—Cascajo gravelly sandy loam, 5 to 20 percent 60-Shingle clay loam, 0 to 9 percent slopes 41
slopes 20 61-Stoneham fine sandy loam, 0 to 6 percent
21—Cushman fine sandy loam, 0 to 6 percent slopes 41
slopes 21 62—Stoneham fine sandy loam, 6 to 9 percent
22—Cushman fine sandy loam, 6 to 9 percent slopes 42
slopes 22 63—Tassel loamy fine sand, 5 to 20 percent slopes. 42
23—Dacono clay loam, 0 to 6 percent slopes 22 64—Terry sandy loam, 0 to 3 percent slopes 42
24—Eckley sandy clay loam, 0 to 6 percent slopes... 22 65—Terry sandy loam, 3 to 9 percent slopes 43
25—Eckley sandy clay loam, 6 to 9 percent slopes... 23 66—Thedalund-Keota loams, 0 to 3 percent slopes 43
26—Eckley-Dix-Blakeland complex, 6 to 20 percent 67—Thedalund-Keota loams, 3 to 9 percent slopes 44
slopes 23 68—Treon fine sandy loam, 5 to 20 percent slopes.. 44
27—Epping silt loam, 0 to 9 percent slopes 24 69—Treon-Rock outcrop complex, 9 to 40 percent
28—Haplaquolls-Fluvaquents complex, frequently slopes 45
flooded 24 70—Ustic Torriorthents-Rock outcrop complex, 9 to
29—Haverson loam, 0 to 3 percent slopes 25 40 percent slopes 45
30—Keith loam, 0 to 6 percent slopes 25 71—Vona loamy sand, 0 to 3 percent slopes 46
31—Kim-Mitchell complex, 0 to 6 percent slopes 26 72—Vona loamy sand, 3 to 9 percent slopes 46
32—Kim-Mitchell complex, 6 to 9 percent slopes 27 73—Vona sandy loam, 0 to 3 percent slopes 47
33—Kim-Shingle complex, 6 to 30 percent slopes 27 74—Vona sandy loam, 3 to 9 percent slopes 47
34—Manter sandy loam, 0 to 6 percent slopes 28 75—Wages fine sandy loam, 0 to 6 percent slopes... 48
35—Manter sandy loam, 6 to 9 percent slopes 28 76—Wages fine sandy loam, 6 to 9 percent slopes... 48
36—Manzanola clay loam, 0 to 3 percent slopes 29 77—Weld loam, 0 to 6 percent slopes 49
37—Midway clay loam, 0 to 9 percent slopes 29
iv
£84572 4.
13
Weld County, Colorado, Northern Part
4—Ascalon fine sandy loam, 0 to 6 percent slopes. 5—Ascalon fine sandy loam, 6 to 9 percent slopes.
This deep, well drained soil is on smooth to moderately This deep, well drained soil is on moderately dissected
dissected plains. It formed in calcareous loamy alluvium. to highly dissected plains. It formed in calcareous loamy
Typically, the surface layer is dark brown fine sandy alluvium.
loam 8 inches thick. The subsoil is sandy clay loam 14 Typically, the surface layer is dark brown fine sandy
inches thick. The substratum to a depth of 60 inches or loam 6 inches thick. The subsoil is sandy clay loam 15
more is calcareous sandy loam. In some areas the inches thick. The substratum to a depth of 60 inches or
surface layer is loam. more is calcareous sandy loam. In some areas the
Included in this unit are small areas of Ascalon fine surface layer is loam.
Included in this unit are small areas of Altvan fine
sandy loam that has slopes of 6 to 9 percent, Olney fine sandy loam, Cascajo gravelly sandy loam, and Peetz
sandy loam, and Otero sandy loam. Also included are gravelly sandy loam. Also included are some areas of
some areas of Rock outcrop. Rock outcrop.
Permeability of this Ascalon soil is moderate. Available Permeability of this Ascalon soil is moderate. Available
water capacity is high. Effective rooting depth is 60 water capacity is high. Effective rooting depth is 60
inches or more. Runoff is slow to medium, and the inches or more. Runoff is medium to rapid, and the
hazard of water erosion is slight to moderate. The hazard of water erosion is high. The hazard of soil
hazard of soil blowing is moderate. blowing is moderate.
This unit is used as nonirrigated cropland and This unit is used as rangeland and nonirrigated
rangeland. Winter wheat is the main crop. cropland. Areas of nonirrigated cropland are poorly
This unit is well suited to winter wheat, barley, oats, suited for use as rangeland and should be seeded to
and sorghum. Because precipitation is not sufficient for adapted grasses.
annual cropping, a cropping system that includes small The potential plant community on this unit is mainly
grain and summer fallow is most suitable. Precipitation blue grama, western wheatgrass, sedges, and
usually is too low for crops on this unit to make efficient buffalograss. The average annual production of air-dry
use of fertilizer. vegetation ranges from 400 to 1,300 pounds.
Maintaining crop residue on or near the surface If the range is overgrazed, the proportion of preferred
reduces runoff, reduces soil blowing, and helps to forage plants decreases and the proportion of less
maintain soil tilth and organic matter content. Stubble- preferred forage plants increases. Therefore, livestock
mulch farming, striperopping, and minimum tillage help to grazing should be managed so that the desired balance
control erosion and conserve moisture. Terraces reduce of preferred species is maintained in the plant
runoff and the risk of erosion and help to conserve community.
moisture. Range seeding is suitable if the range is in poor
The potential plant community on this unit is mainly condition. The plants selected for seeding should meet
blue grama, western wheatgrass, sedges, and the seasonal requirements of livestock or wildlife, or
buffalograss. The average annual production of air-dry both. Other management practices that are suitable for
vegetation ranges from 500 to 1,500 pounds. use on this unit are proper range use, deferred grazing,
If the range is overgrazed, the proportion of preferred and rotation grazing. If the plant cover is disturbed,
forage plants decreases and the proportion of less protection from erosion is needed. Loss of the surface
preferred forage plants increases. Therefore, livestock layer results in a severe decrease in productivity and in
grazing should be managed so that the desired balance the potential of the soil to produce plants suitable for
of preferred species is maintained in the plant grazing.
community. This unit is well suited to windbreaks and
Range seeding is suitable if the range is in poor environmental plantings. Supplemental irrigation may be
condition. The plants selected for seeding should meet needed when planting and during dry periods.
the seasonal requirements of livestock or wildlife, or This map unit is in capability subclass Vie,
both. Other management practices that are suitable for nonirrigated, and in Loamy Plains range site.
use on this unit are proper range use, deferred grazing,
and rotation grazing. If the plant cover is disturbed, 6—Ascalon-Blakeland complex, 3 to 15 percent
protection from erosion is needed. Loss of the surface slopes. This map unit is on alluvial and colluvial fans
layer results in a severe decrease in productivity and in and on moderately dissected to highly dissected plains.
the potential of the soil to produce plants suitable for This unit is 50 percent Ascalon fine sandy loam and
grazing. 30 percent Blakeland loamy sand. The components of
This unit is well suited to windbreaks and this unit are so intricately intermingled that it was not
environmental plantings. Supplemental irrigation may be practical to map them separately at the scale used.
seeded when planting and during dry periods. Included in this unit is about 20 percent Bushman fine
This map unit is in capability subclass IVe, sandy loam, Bresser sandy loam, and Wages fine sandy
nonirrigated, and in Loamy Plains range site. loam.
."J1572 4
38 Soil survey
of preferred species is maintained in the plant buffalograss. The average annual production of air-dry
community. vegetation ranges from 500 to 1.500 pounds.
If the plant cover is disturbed, protection from erosion If the range is overgrazed, the proportion of preferred
is needed. Loss of the surface layer results in a severe forage plants decreases and the proportion of less
decrease in productivity and in the potential of the unit to preferred forage plants increases. Therefore, livestock
produce plants suitable for grazing. Slope limits access grazing should be managed so that the desired balance
by livestock and results in overgrazing of the less sloping of preferred species is maintained in the plant
areas. community.
Management practices suitable for use on this unit are Range seeding is suitable if the range is in poor
proper range use, deferred grazing, and rotation grazing. condition. The plants selected for seeding should meet
Livestock grazing should be managed to protect the unit the seasonal requirements of livestock or wildlife, or
from excessive erosion. Mechanical treatment is not both. Other management practices that are suitable for
practical because of the areas of Rock outcrop and the use on this unit are proper range use, deferred grazing,
steepness of slope. and rotation grazing. If the plant cover is disturbed,
This unit is poorly suited to windbreaks and protection from soil blowing is needed. Loss of the
environmental plantings. The main limitations of the surface layer results in a severe decrease in productivity
Peetz soil are the high content of lime, moderate and in the potential of the soil to produce plants suitable
available water capacity, and steepness of slope. for grazing.
Supplemental irrigation may be needed when planting This unit is well suited to windbreaks and
and during dry periods. environmental plantings. Supplemental irrigation may be
This map unit is in capability subclass Vlls, needed when planting and during dry periods.
nonirrigated, and in Gravel Breaks range site. This map unit is in capability subclass IV, nonirrigated,
54—Platner loam, 0 to 3 percent slopes. This deep, and in Loamy Plains range site.
well drained soil is on smooth to slightly dissected plains 55—Renohill fine sandy loam, 0 to 6 percent
and adjacent stream terraces. It formed in calcareous slopes. This moderately deep, well drained soil is on
loamy alluvium. slightly dissected to moderately dissected plains. It
Typically, the surface layer is grayish brown loam 4 iformed in calcareous loamy or clayey residuum derived
nches thick. The subsoil is clay, clay loam, and silty clay dominantly from shale.
loam 20 inches thick. The substratum to a depth of 60
inches or more is calcareous fine sandy loam and sandy Typically, the surface layer is brown fine sandy loam 5
loam. inches thick. The subsoil is clay loam 13 inches thick.
•
Included in this unit are small areas of Ascalon fine The substratum is calcareous clay loam 14 inches thick.
sandy loam, Manzanola clay loam, and Nunn clay loam. Shale is at a depth of 32 inches. Depth to shale ranges
Also included are soils that have a fine sandy loam or from 20 to 40 inches. In some areas the surface layer is
sandy loam surface layer. loam or clay loam.
Permeability of this Platner soil is slow. Available water Included in this unit are small areas of Midway clay
capacity is high. Effective rooting depth is 60 inches or loam, Shingle loam, and Rock outcrop of shale.
more. Runoff is slow, and the hazard of water erosion is Permeability of this Renohill soil is slow. Available
slight. The hazard of soil blowing is moderate. water capacity is moderate. Effective rooting depth is 20
This unit is used as nonirrigated cropland and to 40 inches. Runoff is medium, and the hazard of water
rangeland. Winter wheat is the main crop. erosion is slight to moderate. The hazard of soil blowing
This unit is well suited to winter wheat, barley, oats, is moderate.
and sorghum. Low annual precipitation is the main This unit is used as rangeland and nonirrigated
limitation for the crops that can be grown on this unit. cropland.
Because precipitation is not sufficient for annual The potential plant community on this unit is mainly
cropping, a cropping system that includes small grain blue grama, western wheatgrass, sedges, and
and summer fallow is most suitable. Precipitation usually buffalograss. The average annual production of air-dry
is too low for crops on this unit to make efficient use of vegetation ranges from 500 to 1,500 pounds.
fertilizer. If the range is overgrazed, the proportion of preferred
Maintaining crop residue on or near the surface forage plants decreases and the proportion of less .
reduces runoff, reduces soil blowing, and helps to preferred forage plants increases. Therefore, livestock 4.
maintain soil tilth and organic matter content. Stubble- grazing should be managed so that the desired balance
mulch farming, striperopping, and minimum tillage help to of preferred species is maintained in the plant
control erosion and conserve moisture. Terraces reduce community.
runoff and the risk of erosion and help to conserve Range seeding is suitable if the range is in poor °
moisture. condition. The plants selected for seeding should meet
The potential plant community on this unit is mainly the seasonal requirements of livestock or wildlife, or
blue grama, western wheatgrass, sedges, and - both. Other management practices that are suitable for
•
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