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HomeMy WebLinkAbout20000669.tiff £ r - c +�"" .*ask S, 'Fr �, v�l i e * i : ; �'.'K i ^k- l 4F) I_. y t Y ) , 5- �f 'x_.Y.-,'' iT Y +�...R}. 4 .Y+ Y k _ 6 • .fi K 1 F 6 J t Ltt . soilsurveyof �. 6 v� Weld Ciountyr Colorado �-„ .• Southern .1` Part :4-1: i l JJ S:rt y�;:';''31'7-.:4,,;7 �7" _1 'L y :1 ;: : L '4 E k .,f -',•!7:'2, .. 3L'' Y‘4,1t1� V .w 1 ;;:/ Tit e '';.-2,.:,--,..' '' 1..: Oh-Li; 4 - '4t s� _ F e ✓' 3 a .iii." O r, s ., r Y �, -+ k r ' '(� it ` w Y 1 • -y Y��pp • ffi.4 4: • e5"{ a '",, •; United States Deportment of Agriculture Soil Conservation Service in cooperation with Colorado Agricultural Experiment Station EXHIBIT 2000-0669 26 SOIL SURVEY shale is about 18 inches. Permeability is moderate. Availa- plication of barnyard manure and commercial fertilizer. ble water capacity is low. The effective rooting depth is Keeping tillage to a minimum and utilizing crop residue 10 to 20 inches. Surface runoff is medium to rapid, and are important. the erosion hazard is moderate. In nonirrigated areas this soil is suited to winter wheat. This unit is used as rangeland and wildlife habitat. The barley, and sorghum. Most of the acreage is planted tc potential native vegetation is dominated by alkali sacaton, winter wheat and is summer fallowed in alternate years western wheatgrass, and blue grama. Buffalograss, to allow moisture accumulation. Generally precipitation is sideoats grama, needleandthread, little bluestem, sedge, too low for beneficial use of fertilizer. winterfat, and fourwing saltbush are also present. Poten- Stubble mulch fanning, striperopping, and minimum til- tial production ranges from 800 pounds per acre in lage are needed to control soil blowing and water erosion. favorable years to 500 pounds in unfavorable years. As The potential native vegetation on this range site is range condition deteriorates, the mid grasses decrease dominated by sand bluestem, sand reedgrass, and blue and forage production drops. Undesirable weeds and an- grama. Needleandthread, switchgrass, sideoats grama nuals invade the site as range condition becomes poorer. and western wheatgrass are also prominent. Potentia Management of vegetation on this unit should be based production ranges from 2,200 pounds per acre in favora on taking half and leaving half of the total annual produc- ble years to 1,800 pounds in unfavorable years. As range tion. Seeding is desirable if the range is in poor condition. condition deteriorates, the sand bluestem, sand reedgrass Western wheatgrass, blue grama, alkali sacaton, sideoats and switchgrass decrease and blue grama, sand dropseed grama, little bluestem, pubescent wheatgrass, and crested and sand sage increase. Annual weeds and grasses invade wheatgrass are suitable for seeding. The grass selected the site as range condition becomes poorer. should meet the seasonal requirements of livestock. It can Management of vegetation on this soil should be base( be seeded into a clean, firm sorghum stubble, or it can be on taking half and leaving half of the total annual produc drilled into a firm prepared seedbed. Seeding early in tion. Seeding is desirable if the range is in poor conditior spring has proven most successful. Sand bluestem, sand reedgrass, switchgrass, sideoat. Rangeland wildlife, such as antelope, cottontail, and grama, blue grama, pubescent wheatgrass, and crestec coyote, are best suited to this unit. Because forage wheatgrass are suitable for seeding. The grass selectee production is typically low,grazing management is needed should meet the seasonal requirements of livestock. It ca: if livestock and wildlife share the range. Livestock water- be seeded into a clean, firm sorghum stubble, or it can b ing facilities also are utilized by various wildlife species. drilled into a firm prepared seedbed. Seeding early is The nearby cropland makes areas of this unit valuable as spring has proven most successful. escape cover for openland wildlife, especially pheasants. Windbreak and environmental plantings are generall Capability subclass VIe irrigated, VIe nonirrigated; Shaly not suited to this soil. Onsite investigation is needed t Plains range site. determine if plantings are feasible. 37—Nelson fine sandy loam, 0 to 3 percent slopes. Wildlife is an important secondary use of this soil. Th This is a moderately deep, well drained soil on plains at cropland areas provide favorable habitat for ring-necke elevations of 4,800 to 5,050 feet. It formed in residuum pheasant and mourning dove. Many nongame species ca from soft sandstone. Included in mapping are small areas be developed by establishing areas for nesting and escap of soils that have sandstone at a depth of more than 40 cover. For pheasants, undisturbed nesting cover is esser inches. tial and should be included in plans for habitat develop Typically the surface layer is light brownish gray fine ment, especially in areas of intensive agriculture. Range sandy loam about 9 inches thick. The underlying material land wildlife, for example, the pronghorn antelope, can b is light olive brown fine sandy loam. Soft sandstone is at attracted by developing livestock watering facilitie. a depth of about 30 inches. managing livestock grazing, and reseeding where needed. Permeability is moderately rapid. Available water The underlying sandstone is the most limiting featur capacity is moderate. The effective rooting depth is 20 to of this soil. Neither septic tank absorption fields nc 40 inches. Surface runoff is slow to medium, and the ero- sewage lagoons operate properly. Site preparation fc sion hazard is low. dwellings is more costly. Environmental and beautificc This soil is suited to most of the irrigated crops com- tion plantings of trees and shrubs may be difficult t monly grown in the area, but it is somewhat restricted establish. This soil, however, does have good potential fc because it is only moderately deep. A suitable cropping such recreational development as camp and picnic are system is corn, corn for silage, barley, 3 to 4 years of al- and playgrounds. Capability subclass Ills irrigated, IN falfa, and wheat. This soil is also well suited to irrigated nonirrigated; Sandy Plains range site. pasture. 38—Nelson fine sandy loam, 3 to 9 percent slope Row crops can be irrigated by furrows or sprinklers. This is a moderately deep, well drained soil on plains Flooding from contour ditches and sprinkling are suitable elevations of 4,800 to 5,050 feet. It formed in residuu in irrigating close grown crops and pasture. Small heads derived from soft sandstone. Included in mapping a, of water and short runs help to reduce erosion. Produc- small areas of soils that have sandstone at a depth tion can be maintained with frequent irrigations and ap- more than 40 inches. WELD COUNTY, COLORADO, SOUTHERN PAZ.i 27 - Typically the surface layer is light brownish gray fine establish. This soil, however, does have good potential for r=`sandy loam about 8 inches thick. The underlying material such recreational development as camp and picnic areas is light olive brown fine sandy loam. Soft sandstone is at and playgrounds. Capability subclass IVe irrigated, VIe a depth of about 28 inches. nonirrigated; Sandy Plains range site. Permeability is moderately rapid. Available water 39—Nunn loam, 0 to 1 percent slopes. This is a deep, opacity is moderate. The effective rooting depth is 20 to well drained soil on terraces at elevations of 4,550 to 5,000 40 inches. Surface runoff is medium to rapid, and the ero- feet. It formed in mixed alluvium. Included in mapping sion hazard is moderate. are small, long and narrow areas of sand and gravel. This soil is suited to limited cropping. Intensive deposits and small areas of soil that are subject to occa- cropping is hazardous because of erosion. The cropping sional flooding. Some small leveled areas are also in- system should be limited to such close grown crops as al- eluded. falfa, wheat, and barley. This soil is also suited to ir- Typically the surface layer of this Nunn soil is grayish rigated pasture. A suitable cropping system is 3 to 4 brown loam about 12 inches thick. The subsoil is light years of alfalfa followed by 2 years of corn and small brownish gray clay loam about 12 inches thick. The upper grain and alfalfa seeded with a nurse crop. part of the substratum is light brownish gray clay loam. Close grown crops can be irrigated from closely spaced The lower part to a depth of 60 inches is brown sandy contour ditches or sprinklers. Contour furrows or sprin- loam. klers should be used for new crops. Applications of Permeability is moderately slow. Available water nitrogen and phosphorus help in maintaining good produc- capacity is high. The effective rooting depth is 60 inches tion. or more. Surface runoff is slow, and the erosion hazard is The potential native vegetation on this range site is low. dominated by sand bluestem, sand reedgrass, and blue This soil is used almost entirely for irrigated crops. It grams. Needleandthread, switchgrass, sideoats grams, is suited to all crops commonly grown in the area, includ- and western wheatgrass are also prominent Potential ing corn, sugar beets, beans, alfalfa, small grain, potatoes, production ranges from 2,200 pounds per acre in favors- and onions. An example of a suitable cropping system is 3 ble years to e1,800rior pounds in unfavorable years. range to 4 years of alfalfa followed by corn, corn for silage, condition deteriorates, the sand bluestem, sand reedgrass, sugar beets, small grain, or beans. Few conservation prat- and adswitchgrass decrease and blue grams, sand esinv dropseed, tices are needed to maintain top yields. and sand sage increase. Annual weeds and grasses invade All methods of irrigation are suitable, but furrow ir- the site as range condition becomes poorer. rigation is the most common. Barnyard manure and com- Management of vegetation on this soil should be based mercial fertilizer are needed for top yields. on taking half and leaving half of the total annual produc- Windbreaks and environmental plantings of trees and tion. Seeding is desirable if the range is in poor condition. shrubs commonly grown in the area are generally well Sand bluestem, sand reedgrass, switchgrass, sideoats suited to this soiL Cultivation to control competing grams, blue grams, pubescent wheatgrass, and crested vegetation should be continued for as many years as wheatgrass are suitable for seeding. The grass selected possible following planting. Trees that are best suited and should meet the seasonal requirements of livestock. It can be seeded into a clean, firm sorghum stubble, or it can be have good survival are Rocky Mountain juniper, eastern drilled into a firm prepared seedbed. Seeding early in redcedar, ponderosa pine, Siberian elm, Russian-olive, and hackberry. The shrubs best suited are skunkbush, lilac, spring has proven most successful. Windbreaks and environmental plantings are generally Siberian peashrub, and American plum. not suited. Onsite investigation is needed to determine if Wildlife is an important secondary use of this soil. The plantings are feasible. cropland areas provide favorable habitat for ring-necked Wildlife is an important secondary use of this soil. The pheasant and mourning dove. Many nongame species can cropland areas provide wildlife habitat for ring-necked be attracted by establishing areas for nesting and escape pheasant and mourning dove. Many nongame species can cover. For pheasants, undisturbed nesting cover is essen- be attracted by establishing areas for nesting and escape tial and should be included in plans for habitat develop- coven For pheasants, undisturbed nesting cover is essen- ment, especially in areas of intensive agriculture. tial and should be included in plans for habitat develop- This soil has fair to poor potential for urban develop- ment, especially in areas of intensive agriculture. Range- ment. It has moderate to high shrink swell, low strength, land wildlife, for example, the pronghorn antelope, can be and moderately slow permeability. These features create attracted by developing livestock watering facilities, problems in dwelling and road construction. Those areas managing livestock grazing, and reseeding where needed. that have loam or sandy loam in the lower part of the The underlying sandstone is the most limiting feature substratum are suitable for septic tank absorption fields of this soil. Neither septic tank absorption fields nor and foundations. Some areas are adjacent to streams and sewage lagoons operate properly. Site preparation for are subject to occasional flooding.This soil has fair poten- dwellings is more costly. Environmental and beautifica- tial for such recreational development as camp and picnic tion plantings of trees and shrubs may be difficult to areas and playgrounds. Capability class I irrigated. 40 SOIL SURVEY from 800 pounds per acre in favorable years to 500 production ranges from 1,750 pounds per acre in favor _ pounds in unfavorable years. As range condition deteri- ble years to 950 pounds in unfavorable years. As ran; orates, the mid grasses decrease and forage production condition deteriorates, the sideoats grama, little blueste; drops. Undesirable weeds and annuals invade the site as and sand reedgrass decrease; yucca, sedge, and bL range condition becomes poorer. grama increase; and forage production drops. Management of vegetation on the Shingle soil should be Management of vegetation should be based on taki1 based on taking half and leaving half of the total annual half or less of the total annual production. Deferred gra production. Seeding is desirable if the range is in poor ing is practical in improving range condition. Seeding al condition. Western wheatgrass, blue grama, alkali sacaton, mechanical treatment are impractical. sideoats grama, little bluestem, pubescent wheatgrass, Windbreaks and environmental plantings are general and crested wheatgrass are suitable for seeding. The not suited to this soil. Onsite investigation is needed grass selected should meet the seasonal requirements of determine if plantings are feasible. livestock. It can be seeded into a clean, firm sorghum Production of vegetation on this treeless soil is lo stubble, or it can be drilled into a firm prepared seedbed. especially during drought, when annual production can 1 Seeding early in spring has proven most successfuL as low as 300 pounds per acre. Rangeland wildlife, such The potential native vegetation on the Renohill soil is antelope and scaled quail, can be attracted by managh dominated by western wheatgrass and blue grama. Buf- livestock grazing, installing livestock watering facilitic falograss is also presented. Potential production ranges and reseeding where needed. from 1,000 pounds per acre in favorable years to 600 This soil has poor potential for urban development. TI pounds in unfavorable years. As range condition deteri- chief limiting feature is the shallow depth to sandstor orates, a blue grama-buffalograss sod forms. Undesirable Capability subclass VIe irrigated, VIe nonirrigated; San weeds and annuals invade the site as range condition stone Breaks range site. becomes poorer. 62—Terry fine sandy loam, 0 to 3 percent slopes. TI is a moderately deep, well drained soil on plains at elev Management of vegetation on the Renohill soil should be based on taking half and leaving half of the total an- tions of 4,500 to 5,000 feet. It formed in residuum fro nual production. Range pitting can reduce runoff. Seeding sandstone. Included in mapping are small areas of soi is desirable if the range is in poor condition. Western that have sandstone deeper than 40 inches. Also include wheatgrass, blue grama, sideoats grama, buffalograss are small areas of soils that have a subsoil of sandy cl Pu loam and clay loam. bescent wheatgrass, and crested wheatgrass are suitable for seeding. The grass selected should meet the seasonal Typically the surface layer of this Terry soil is pa requirements of livestock. It can be seeded into a clean, brown fine sandy loam about 6 inches thick. The subsoil firm pale brown fine sandy loam about 21 inches thick. TI firm sorghum stubble, or it can be drilled into a prepared seedbed. Seeding early in spring has substratum is very pale brown fine sandy loam. San, p ' g proven stone is at a depth p of about 37 inches. most successful. Rangeland wildlife, such as antelope, cottontail, and Permeability is moderately rapid. Available wat capacity is moderate. The effective rooting depth is 20 coyote, are best suited to this unit. Because forage production is typically low, 40 inches. Surface runoff is slow, and the erosion hazai grazing management is needed is low. if livestock and wildlife share the range. Livestock water- This soil is suited to most of the irrigated crops col- ing facilities also are utilized by various wildlife species. monly grown in the area. The moderate depth restric Capability subclass VIe irrigated, VIe nonirrigated; Shin- some crops. A suitable cropping system is corn, corn n gle soil in Shaly Plains range site, Renohill soil in Clayey silage, barley, 3 to 4 years of alfalfa, and wheat. This sc Plains range site. is also well suited to irrigated pasture. 61—Tassel fine sandy loam, 5 to 20 percent slopes. Furrows or sprinklers can be used in irrigating ro This is a shallow, well drained soil on upland breaks at crops. Flooding from contour ditches and sprinkling al elevations of 4,850 to 5,200 feet. It formed in residuum suitable in irrigating close grown crops and pasture. Sms from sandstone. Included in mapping are small areas of heads of water and short runs reduce the risk of erosio sandstone outcrop and areas of noncalcareous soils. Production can be maintained by frequent irrigations ar Typically the surface layer of this Tassel soil is light by applications of barnyard manure and commercial fert yellowish brown fine sandy loam about 7 inches thick. The izer. Keeping tillage to a minimum and utilizing crc underlying material is light yellowish brown very fine residue are important. sandy loam. Sandstone is at a depth of about 11 inches. In nonirrigated areas this soil is suited to winter whet Permeability is moderately rapid. Available water barley, and sorghum. Most of the acreage is planted ; capacity is low. The effective rooting depth is 10 to 20 winter wheat. The predicted average yield is 25 bushe inches. Surface runoff is medium, and the erosion hazard per acre. The soil is summer fallowed in alternate yea: is moderate, to allow moisture accumulation. Generally precipitation The potential native vegetation is dominated by too low for beneficial use of fertilizer. _ sideoats grama, little bluestem, blue grama, threadleaf Stubble mulch farming, striperopping, and minimum ti sedge, sand reedgrass, and needleandthread. Potential lage are needed to control soil blowing and water erosior WELD COUNTY, COLORADO, SOUTHERN PART 41 The potential native vegetation on this range site is This soil is suited to limited cropping. Intensive dominated by sand bluestem, sand reedgrass, and blue cropping is hazardous because of erosion. The cropping grama. Needleandthread, switchgrass, sideoats grama, system should be limited to such close grown crops as al- and western wheatgrass are also prominent. Potential falfa, wheat, and barley. The soil is also suited to ir- production ranges from 2,200 pounds per acre in favora- rigated pasture. A suitable cropping system is 3 to 4 ble years to 1,800 pounds in unfavorable years. As range years of alfalfa followed by 2 years of corn and small condition deteriorates, the sand bluestem, sand reedgrass, grain and alfalfa seeded with a nurse crop. and switchgrass decrease and blue grama, sand dropseed, Closely spaced contour ditches or sprinklers can be and sand sage increase. Annual weeds and grasses invade used in irrigating close grown crops. Contour furrows or the site as range condition becomes poorer. sprinklers should be used for new crops. Applications of Management of vegetation on this soil should be based nitrogen and phosphorus help in maintaining good produc- on taking half and leaving half of the total annual produc- tion. tion. Seeding is desirable if the range is in poor condition. The potential native vegetation on this range site is Sand bluestem, sand reedgrass, switchgrass, sideoats dominated by sand bluestem, sand reedgrass, and blue grama, blue grama, pubescent wheatgrass, and crested grama. Needleandthread, switchgrass, sideoats grama, wheatgrass are suitable for seeding. The grass selected and western wheatgrass are also prominent. Potential should meet the seasonal requirements of livestock. It can production ranges from 2,200 pounds per acre in favora- be seeded into a clean, firm sorghum stubble or it can be ble years to 1,800 pounds in unfavorable years. As range drilled into a firm prepared seedbed. Seeding early in condition deteriorates, the sand bluestem, sand reedgrass, spring has proven most successful. and switchgrass decrease and blue grams, sand dropseed, Windbreaks and environmental plantings are generally and sand sage increase. Annual wcsds and grasses invade not suited to this soil. Onsite investigation is needed to the site as range condition becomes poorer. determine if plantings are feasible. Management of vegetation on this soil should be based Wildlife is an important secondary use of this soil. The on taking half and leaving half of the total annual produc- cropland areas provide favorable habitat for ring-necked tion. Seeding is desirable if the range is in poor condition. pheasant and mourning dove. Many nongame species can Sand bluestem, sand reedgrass, switchgrass, sideoats be attracted by establishing areas for nesting and escape grama, blue grams, pubescent wheatgrass, and crested cover. For pheasants, undisturbed nesting cover is essen- wheatgrass are suitable for seeding. The grass selected tial and should be included in plans for habitat develop- should meet the seasonal requirements of livestock. It can ment, especially in areas of intensive agriculture. Range- be seeded into a clean, firm sorghum stubble, or it can be land wildlife, for example, the pronghorn antelope, can be drilled into a firm prepared seedbed. Seeding early in attracted by developing livestock watering facilities, spring has proven most successful. managing livestock grazing, and reseeding where needed. Windbreaks and environmental plantings are generally The underlying sandstone is the most limiting feature not suited to this soil. Onsite investigation is needed to of this soil. Neither septic tank absorption fields nor determine if plantings are feasible. sewage lagoons function properly. Site preparation for Wildlife is an important secondary use of this soil. The dwellings is costly. Enviornmental and beautification cropland areas provide favorable habitat for ring-necked plantings of trees and shrubs can be difficult to establish. pheasant and mourning dove. Many nongame species can Potential is good, however, for such recreational develop- be attracted by establishing areas for nesting and escape ment as camp and picnic areas and playgrounds. Capabili- cover. For pheasants, undisturbed nesting cover is essen- ty subclass IVe irrigated, IVe nonirrigated; Sandy Plains tial and should be included in plans for habitat develop- range site. ment, especially, in areas of intensive agriculture. Range- 63—Terry fine sandy loam, 3 to 9 percent slopes. This land wildlife, for example, the pronghorn antelope, can be is a moderately deep, well drained soil on plains at eleva- attracted by developing livestock watering facilities, tions of 4,500 to 5,000 feet. It formed in residuum from managing livestock grazing, and reseeding where needed. sandstone. Included in mapping are small areas of soils The underlying sandstone is the most limiting feature that have sandstone deeper than 40 inches. Also included of this soil. Neither septic tank absorption fields nor are small areas of soils that have a sandy clay loam and sewage lagoons function properly. Site preparation for clay loam subsoil. dwellings is costly. Environmental and beautification Typically the surface layer of this Terry soil is pale plantings of trees and shrubs can be difficult to establish. brown fine sandy loam about 6 inches thick. The subsoil is Potential is good, however, for such recreational develop- pale brown fine sandy loam about 18 inches thick. The ment as camp and picnic areas. Capability subclass IVe ir- substratum is fine sandy loam. Sandstone is at a depth of rigated, Vie nonirrigated; Sandy Plains range site. about 32 inches. 64—Thedalund loam, 1 to 3 percent slopes. This is a Permeability is moderately rapid. Available water moderately deep, well drained soil on plains at elevations _ capacity is moderate. The effective rooting depth is 20 to of 4,900 to 5,250 feet. It formed in residuum from shale. 40 inches. Surface runoff is medium to rapid, and the ero- Included in mapping are small areas of soils that have sion hazard is moderate. shale and sandstone deeper than 40 inches. 52 SOIL SURVEY the limited capacity of this soil to support a load. Capa- Management of vegetation on this soil should be b bility class I irrigated. on taking half and leaving half of the total annual prc 82—Wiley-Colby complex, 1 to 3 percent slopes. This tion. Seeding is desirable if the range is in poor condi nearly level map unit is on smooth plains in the western Sideoats grama, little bluestem, western wheatgrass, part of the survey area at elevations of 4,850 to 5,000 grama, pubescent wheatgrass, and crested wheatgras: feet. The Wiley soil makes up about 60 percent of the suitable for seeding. The grass selected should meet unit, and the Colby soil about 30 percent. About 10 per- seasonal requirements of livestock. It can be seeded cent is Heldt silty clay and Weld loam. a clean, firm sorghum stubble or it can be drilled it The Wiley soil is deep and well drained. It formed in firm prepared seedbed. Seeding early in spring calcareous eolian deposits. Typically the surface layer is proven most successful. pale brown silt loam about 11 inches thick. The subsoil is Windbreaks and environmental plantings are gene pale brown silty clay loam about 23 inches thick. The sub- well suited to these soils. Cultivation to control comp( stratum to a depth of 60 inches is very pale brown silty vegetation should be continued for as many year clay loam. possible following planting. Trees that are best suitec Permeability is moderately slow. Available water have good survival are Rocky Mountain juniper, ea: capacity is high. The effective rooting depth is 60 inches redcedar, ponderosa pine, Siberian elm, Russian-olive or more. Surface runoff is medium, and the erosion hackberry. The shrubs best suited are skunkbush st hazard is moderate. lilac, Siberian peashrub, and American plum. The Colby soil also is deep and well drained and formed Openland wildlife, such as pheasant, mounting in calcareous eolian deposits. Typically the surface layer and cottontail are best suited to these soils. Wi is pale brown loam about 7 inches thick. The underlying habitat development, including tree and shrub plan material is very pale brown silt loam to a depth of 60 and grass plantings to serve as nesting areas, shou inches. successful without irrigation during most years. Undi Permeability is moderate. Available water capacity is rigation, good wildlife habitat can be established, bei high. The effective rooting depth is 60 inches or more. ing many kinds of openland wildlife. Surface runoff is medium, and the erosion hazard is The Wiley soil has only fair potential for urban moderate. recreational development. Slow permeability, mod This map unit is used for irrigated and nonirrigated shrink-swell potential, and limited bearing capacity cropland and for rangeland, wildlife habitat, and urban problems in dwelling and road construction. The development. soil has good potential for urban and recreational des In irrigated areas these soils are suited to all crops ment. Road design can be modified to compensate fo commorly grown in the area, including corn, sugar beets, limited capacity of this soil to support a load. Capa beans, alfalfa, small grain, and onions. An example of a subclass IIe irrigated, IVe nonirrigated; Loamy I suitable cropping system is 3 to 4 years of alfalfa fol- range site. lowed by corn, corn for silage, sugar beets, small grain, or 83—Wiley-Colby complex, 3 to 5 percent slopes. beans. Land leveling, ditch lining, and installing pipelines gently sloping map unit is on plains at elevations of may be needed for proper water applications. to 5,000 feet. The Wiley soil makes up about 60 percE All methods of irrigation are suitable, but furrow ir- the unit, and the Colby soil about 30 percent. Abo rigation is the most common. Barnyard manure and com- percent is Heldt silty clay and Weld loam. mercial fertilizer are needed for top yields. The Wiley soil is deep and well drained. It form In nonirrigated areas these soils are suited to winter calcareous eolian deposits. Typically the surface la} wheat, barley, and sorghum. Most of the acreage is pale brown silt loam about 11 inches thick. The sub: planted to winter wheat. The predicted average yield is pale brown silty clay loam about 23 inches thick. ThE 28 bushels per acre. The soil is summer fallowed in al- stratum to a depth of 60 inches is very pale brown ternate years to allow moisture accumulation. Generally clay loam. precipitation is too low for beneficial use of fertilizer. Permeability is moderately slow. Available Stubble mulch farming, striperopping, and minimum til- capacity is high. The effective rooting depth is 60 i lage are needed to control soil blowing and water erosion. or more. Surface runoff is medium to rapid, and tht Terracing also may be needed to control water erosion. sion hazard is moderate. The potential native vegetation is dominated by blue The Colby soil also is deep and well drained and fE grama. Several mid grasses such as western wheatgrass in calcareous eolian deposits. Typically the surface and needleandthtead are also present. Potential produc- is pale brown loam about 7 inches thick. The under tion ranges from 1,600 pounds per acre in favorable years material is very pale brown silt loam to a depth to 1,000 pounds in unfavorable years. As range condition inches. deteriorates, the mid grasses decrease; blue grama, buf- Permeability is moderate. Available water capac falograss, snakeweed, yucca and fringed sage increase; high. The effective rooting depth is 60 inches or and forage production drops. Undesirable weeds and an- Surface runoff is medium to rapid, and the erosion t nuals invade the site as range condition becomes poorer. is moderate. WELD COUNTY, COLORADO, SOUTHERN PART 53 This unit is used for irrigated and nonirrigated The Wiley soil has only fair potential for urban and .ropland and for rangeland, wildlife habitat, and urban recreational development. Slow permeability, moderate evelopment. shrink-swell potential, and limited bearing capacity cause In irrigated areas these soils are suited to the crops problems in dwelling and road construction. The Colby commonly grown in the area Perennial grasses and alfal- soil has good potential for urban and recreational develop- fa or close grown crops should be grown at least 50 per- ments. Road design can be modified to compensate for cent of the time. Contour ditches and corrugations can be the limited capacity of this soil to support a load. Capa- used in irrigating close grown crops and pasture. Fur- bility subclass IIIe irrigated, IVe nonirrigated; Loamy rows, contour furrows, and cross slope furrows are suita- Plains range site. ble for row crops. Sprinkler irrigation is also desirable. Keeping tillage to a minimum and utilizing crop residue help to control erosion. Maintaining fertility is important. Use and management of the soils Crops respond to applications of phosphorus and nitrogen. The soil survey is a detailed inventory and evaluation In nonirrigated areas these soils are suited to winter of the most basic resource of the survey area—the soil. It wheat, barley, and sorghum. Most of the acreage is is useful in adjusting land use, including urbanization, to planted to winter wheat. The predicted average yield is the limitations and potentials of natural resources and the 28 bushels per acre. The soil is summer fallowed in al- environment. Also, it can help avoid soil-related failures ternate years to allow moisture accumulation. Generally in uses of the land. precipitation is too low for beneficial use of fertilizer. Stubble mulch farming, striperopping, While a soil survey is in progress,keep l xtensives, con- Stubble p pping, and minimum til- servationists, engineers, and others extensive notes lage are needed to control soil blowing and water erosion. about the nature of the soils and about unique aspects of Terracing also may be needed to control water erosion. behavior of the soils. These notes include data on erosion, The potential native vegetation is dominated by blue drought damage to specific crops, yield estimates, flood- grama. Several mid grasses, such as western wheatgrass ing, the functioning of septic tank disposal systems, and and needleandthread, are also present. Potential produc- other factors affecting the productivity, potential, and tion ranges from 1,600 pounds per acre in favorable years limitations of the soils under various uses and manage- to 1,000 pounds in unfavorable years. As range condition ment. In this way, field experience and measured data on deteriorates, the mid grasses decrease; blue grama, buf- soil properties and performance are used as a basis for falograss, snakeweed, yucca, and fringed sage increase; predicting soil behavior. id forage production drops. Undesirable weeds and an- Information in this section is useful in planning use and nuals invade,the site as range condition becomes poorer. management of soils for crops, pasture, and rangeland, as Management of vegetation on these soils should be sites for buildings, highways and other transportation based on taking half and leaving half of the total annual systems, sanitary facilities, and parks and other recrea- production. Seeding is desirable if the range is in poor tion facilities, and for wildlife habitat. From the data condition. Sideoats grama, little bluestem, western wheat- presented, the potential of each soil for specified land uses can be determined, soil limitations to these land uses grass, blue grama, pubescent wheatgrass, and crested wheatgrass are suitable for seeding. The grass selected can be identified, and costly failures in houses and other structures, caused by unfavorable soil properties, can be should meet the seasonal requirements of livestock It can be seeded into a clean, firm sorghum stubble, or it can be avoided. A site where soil properties are favorable can be drilled into a firm prepared seedbed. Seeding early in selected, or practices that will overcome the soil limita- spring has proven most successful. tions can be planned. Planners and others using the soil survey can evaluate Windbreaks and environmental plantings of trees and shrubs commonly grown in the area are generally well the impact of specific land uses on the overall ptivi- suited to these soils. Cultivation to control competing ty of the survey area or other broad planning area and on re vegetation should be' continued for as many years as the environment. Productivity and the environment are of possible following plantings. Trees that are best suited closely related to the maintain nature or create a land-use patt tt the soil. Plans should and have good survival are Rocky Mountain juniper, east- ern in harmony with the ern redcedar, ponderosa pine, Siberian elm, Russian-olive, natural soil. and hackberry. The shrubs best suited are skunkbushContractors sou can and information gravel, that is s in locat- and sumac, lilac,Siberian peashrub, and American plum. ing information os of indicatescad presence roadfill,bedrock,and t wetness,s or Openland wildlife, such as pheasant, mourning dove, eryfimsoil rizosthe thatus f difficulty xavatinr and cottontail, are best suited to these soils. Wildlife very Health horizons ause officials, engineers, in r excavation. habitat development, including tree and shrub plantingso Hr r sp officials, highway ists also can useful informaton in nd many is and grass plantings to serve as nesting areas, should be soil esurvey. lThe safe disposal of wastes,°fora example,his successful without irrigation during most years. Under ir- closely related to properties of the soil. Pavements, side- ligation, good wildlife habitat can be established, benefit- walks, campsites, playgrounds, lawns, and trees and many kinds of openland wildlife. shrubs are influenced by the nature of the soil. Hello