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73-528: The first known village in the area was founded in 992 around a castle known as Castell vell . The inhabitants lived off dryland agriculture . This initial nucleus was almost abandoned after the black plague caused numerous deaths. The area was resettled in the 14th century and gradually prospered. Nowadays there are some new housing developments in the area as well as the " Sakya Tashi Ling " Buddhist monastery , located in Plana Novella . The village

146-445: A broad denuded area as a piedmont deposit by the rivers which issued from the mountains. Since then, it has been more or less dissected by the erosion of valleys. The central section of the plains thus presents a marked contrast to the northern section. While the northern section owes its smoothness to the removal of local gravels and sands from a formerly uneven surface by the action of degrading rivers and their inflowing tributaries,

219-828: A broad expanse of flatland in North America . The region is located just to the east of the Rocky Mountains , much of it covered in prairie , steppe , and grassland . They are the western part of the Interior Plains , which include the mixed grass prairie , the tallgrass prairie between the Great Lakes and Appalachian Plateau , and the Taiga Plains and Boreal Plains ecozones in Northern Canada . "Great Plains", or Western Plains ,

292-538: A broad stretch of country underlain by nearly horizontal strata extending westward from the 97th meridian west to the base of the Rocky Mountains , a distance of 300 to 500 mi (480 to 800 km). It extends northward from the Mexican boundary far into Canada. Although the altitude of the plains increases gradually from 600 ft (180 m) or 1,200 ft (370 m) on the east to 4,000–5,000 ft (1,200–1,500 m) or 6,000 ft (1,800 m) near

365-603: A gradual transition, this rainfall line may be taken to divide the drier plains from the moister prairies. However, in Canada the eastern boundary of the plains is well defined by the presence of the Canadian Shield to the northeast. The plains (within the United States) may be described in northern, intermediate, central and southern sections, in relation to certain peculiar features. In Canada, no such division

438-645: A region of human geography , referring to the Plains Indians or the Plains states . In Canada the term is rarely used; Natural Resources Canada , the government department responsible for official mapping, treats the Interior Plains as one unit consisting of several related plateaus and plains. There is no region referred to as the "Great Plains" in the Atlas of Canada . In terms of human geography,

511-594: A west-northwest direction in what is now Oklahoma and Texas which is now known as the De Soto Trail. The Spanish thought that the Great Plains were the location of the mythological Quivira and Cíbola , a place said to be rich in gold. People in the southwest began to acquire horses in the 16th century by trading or stealing them from Spanish colonists in New Mexico. As horse culture moved northward,

584-404: Is about 500 mi (800 km) east to west and 2,000 mi (3,200 km) north to south. Much of the region was home to American bison herds until they were hunted to near extinction during the mid/late-19th century. It has an area of approximately 500,000 sq mi (1,300,000 km ). Current thinking regarding the geographic boundaries of the Great Plains is shown by this map at

657-639: Is abundant, farmers may increase their input efforts and budget to maximize yields and to offset poor harvests. As an area of research and development, arid-zone agriculture, or desert agriculture, includes studies of how to increase the agricultural productivity of lands dominated by lack of freshwater, an abundance of heat and sunlight, and usually one or more of: Extreme winter cold, short rainy season, saline soil or water, strong dry winds, poor soil structure, over-grazing, limited technological development, poverty, or political instability. The two basic approaches are: Great Plains The Great Plains are

730-462: Is also practiced by farmers on a smaller scale by laying out the direction of furrows to slow water runoff downhill, usually by plowing along either contours or keylines . Moisture can be conserved by eliminating weeds and leaving crop residue to shade the soil. Effective use of available moisture: Once moisture is available for the crop to use, it must be used as effectively as possible. Seed planting depth and timing are carefully considered to place

803-556: Is also the ecoregion of the Great Plains or alternatively the western portion of the Great Plains. The Great Plains lie across both the Central United States and Western Canada , encompassing: The term "Great Plains" is used in the United States to describe a sub-section of the even more vast Interior Plains physiographic division, which covers much of the interior of North America. It also has currency as

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876-430: Is an increased risk of crop failure and poor yields which may occur in a dry year (regardless of money or effort expended). Dryland farmers must evaluate the potential yield of a crop constantly throughout the growing season and be prepared to decrease inputs to the crop such as fertilizer and weed control if it appears that it is likely to have a poor yield due to insufficient moisture. Conversely, in years when moisture

949-448: Is associated with drylands , areas characterized by a cool wet season (which charges the soil with virtually all the moisture that the crops will receive prior to harvest) followed by a warm dry season. They are also associated with arid conditions, areas prone to drought and those having scarce water resources. Dryland farming has evolved as a set of techniques and management practices to adapt to limited availability of water, as in

1022-413: Is critical to sustainable agriculture , in particular within arid areas, its preservation is generally considered the most important long-term goal of a dryland farming operation. Erosion control techniques such as windbreaks , reduced tillage or no-till , spreading straw (or other mulch on particularly susceptible ground), and strip farming are used to minimize topsoil loss. Weedling: Weedling

1095-526: Is extraordinarily smooth. It is very dry, except for occasional shallow and temporary water sheets after rains. Llano is separated from the plains on the north by the mature consequent valley of the Canadian River , and from the mountains on the west by the broad and probably mature valley of the Pecos River . On the east, it is strongly undercut by the retrogressive erosion of the headwaters of

1168-509: Is located in the Garraf Massif , in a natural park area, not far from Barcelona . [REDACTED] Media related to Olivella, Spain at Wikimedia Commons This Province of Barcelona location article is a stub . You can help Misplaced Pages by expanding it . Dryland agriculture Dryland farming and dry farming encompass specific agricultural techniques for the non-irrigated cultivation of crops . Dryland farming

1241-418: Is more suited to regions with higher winter rainfall while areas with summer wet seasons may be more suited to summer growing crops such as sorghum , sunflowers or cotton . Dry farmed crops may include grapes , tomatoes , pumpkins , beans , and other summer crops. Dryland grain crops include wheat, corn, millet, rye, and other grasses that produce grains. These crops grow using the winter water stored in

1314-506: Is peculiarly elaborate. Known as the Badlands , it is a minutely dissected form with a relief of a few hundred feet. This is due to several causes: The central section of the Great Plains, between latitudes 42° and 36° , occupying eastern Colorado and western Kansas , is mostly a dissected fluviatile plain. That is, this section was once smoothly covered with a gently sloping plain of gravel and sand that had been spread far forward on

1387-420: Is process of turning over 90 degree and exposing weed's root during tillage to prevent soil erosion by wind and desertification . At the same time, Direct absorption of nutrients from weeds and moisture provides suitable environment to floris biodiversity of organisms in soil. Control of input costs: Dryland farming is practiced in regions inherently marginal for non-irrigated agriculture. Because of this, there

1460-455: Is used: the climatic and vegetation regions are more impactful on human settlement than mere topography, and therefore the region is split into (from north to south), the taiga plains, boreal plains , aspen parkland , and prairie ecoregion regions. The northern section of the Great Plains, north of latitude 44° , includes eastern Montana , eastern Wyoming , most of North Dakota and South Dakota , southwestern Minnesota and portions of

1533-563: The American burying beetle (Nicrophorus americus), Salt Creek Tiger Beetle (Cinidela nevadica lincolniana), Great Plains Giant Tiger Beetle (Amblycheila chylindriformis), Microstylum morosum , Bean leaf beetle (Cerotoma trifurcata), Great Plains Camel Cricket (Daihinia brevipes), and the Great plains spittlebug (Lepyronia gibbosa). Some species in the Great plains have gone extinct in

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1606-593: The Arikara , Mandan , Pawnee , and Wichita . Wars with the Ojibwe and Cree peoples pushed the Lakota (Teton Sioux) west onto the Great Plains in the mid- to late-17th century. The Shoshone originated in the western Great Basin and spread north and east into present-day Idaho and Wyoming. By 1500, some Eastern Shoshone had crossed the Rocky Mountains into the Great Plains. After 1750, warfare and pressure from

1679-825: The Department of the Interior . In contrast, U.S. Forest Service , an agency of the U. S. Department of Agriculture , administers the National Forests and National Grasslands, under a multiple-use concept. By law, the U.S. Forest Service must consider all resources, with no single resource emphasized to the detriment of others, including water, soil, grazing, timber harvesting, and minerals (mining and drilling), as well as recreation and conservation of fish and wildlife. Each individual state also administers state lands, typically smaller areas, for various purposes including conservation and recreation. Grasslands are among

1752-968: The Great Plains toad ( Anaxyrus cognatus ), plains leopard frog ( Lithobates blairi ), and plains spadefoot toad ( Spea bombifrons ). Some species predominately associated with various river basins in the Great Plains include sturgeon chub ( Macrhybopsis gelida ), peppered chub ( Macrhybopsis tetranema ), prairie chub ( Macrhybopsis australis ), western silvery minnow ( Hybognathus argyritis ), plains minnow ( Hybognathus placitus ), smalleye shiner ( Notropis buccula ), Arkansas River shiner ( Notropis girardi ), Red River shiner ( Notropis bairdi ), Topeka shiner ( Notropis topeka ), plains topminnow ( Fundulus sciadicus ), plains killifish ( Fundulus zebrinus ), Red River pupfish ( Cyprinodon rubrofluviatilis ), and Arkansas darter ( Etheostoma cragini ). The great plains also has many invertebrate species living here both alive and extinct such as

1825-506: The Horse Heaven Hills in central Washington, wheat farming has been productive purportedly on an average annual rainfall approaching 6 inches. Consequently, moisture must be captured until the crop can utilize it. Techniques include summer fallow rotation (in which one crop is grown on two seasons' precipitation, leaving standing stubble and crop residue to trap snow), and preventing runoff by terracing fields. "Terracing"

1898-498: The steppes of Eurasia and Argentina . Dryland farming was introduced to southern Russia and Ukraine by Ukrainian Mennonites under the influence of Johann Cornies , making the region the breadbasket of Europe. In Australia, it is widely practiced in all states but the Northern Territory . The choice of crop is influenced by the timing of the predominant rainfall in relation to the seasons. For example, winter wheat

1971-434: The "Great Plains" as an ecoregion synonymous with predominant prairies and grasslands rather than as physiographic region defined by topography. The Great Plains ecoregion includes five sub-regions: Temperate Prairies, West-Central Semi-Arid Prairies, South-Central Semi-Arid Prairies, Texas Louisiana Coastal Plains, and Tamaulipas-Texas Semi-Arid Plain, which overlap or expand upon other Great Plains designations. The region

2044-556: The Blackfoot, Crow, Lakota, Cheyenne, and Arapaho pushed Eastern Shoshone south and westward. Some of them moved as far south as Texas, emerging as the Comanche by 1700. The first known contact between Europeans and Indians in the Great Plains occurred in what is now Texas, Kansas, and Nebraska from 1540 to 1542 with the arrival of Francisco Vázquez de Coronado , a Spanish conquistador. In that same period, Hernando de Soto crossed

2117-503: The Canadian provinces including southeastern Alberta , southern Saskatchewan and southwestern Manitoba . The strata here are Cretaceous or early Tertiary , lying nearly horizontal. The surface is shown to be a plain of degradation by a gradual ascent here and there to the crest of a ragged escarpment, the escarpment-remnant of a resistant stratum. There are also the occasional lava -capped mesas and dike formed ridges, surmounting

2190-462: The Center for Great Plains Studies, University of Nebraska–Lincoln . This definition, however, is primarily ecological, not physiographic. The Boreal Plains of Western Canada are physiographically the same, but differentiated by their tundra and forest (rather than grassland) appearance. The term "Great Plains", for the region west of about the 96th meridian west and east of the Rocky Mountains ,

2263-557: The Comanche were among the first to commit to a fully mounted nomadic lifestyle. This occurred by the 1730s, when they had acquired enough horses to put all their people on horseback. The real beginning of the horse culture of the plains began with the Pueblo Revolt of 1680 in New Mexico and the capture of thousands of horses and other livestock. In 1683 a Spanish expedition into Texas found horses among Native people. In 1690,

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2336-551: The Great Plains and into the valleys and lower elevations of the eastern Rocky Mountains and portions of the American southwest . Other snakes include the plains hog-nosed snake ( Heterodon nasicus ), western milksnake ( Lampropeltis gentilis ), great plains ratsnake ( Pantherophis emoryi ), bullsnake ( Pituophis catenifer sayi ), plains black-headed snake ( Tantilla nigriceps ), plains gartersnake ( Thamnophis radix ), and lined snake ( Tropidoclonion lineatum ). Reptile diversity increases significantly in southern regions of

2409-629: The Great Plains and that included trade networks west to the Rocky Mountains. Mississippians settled the Great Plains at sites now in Oklahoma and South Dakota . Siouan language speakers may have originated in the lower Mississippi River region. They were agriculturalists and may have been part of the Mound Builder civilization during the 9th–12th centuries. Pressure from other Indian tribes, themselves driven west and south by

2482-588: The Great Plains include National Parks and National Monuments, administers by the National Park Service with the responsibility of preserving ecological and historical places and making them available to the public. The U.S. Fish & Wildlife Service manages the National Wildlife Refuges, with the primary responsibility of conserving and protecting fish, wildlife, plants, and habitat in the public trust. Both are agencies of

2555-476: The Great Plains include the swift fox ( Vulpes velox ) and the endangered black-footed ferret ( Mustela nigripes ). The lesser prairie chicken ( Tympanuchus pallidicinctus ) is endemic to the Great Plains and the distribution of the greater prairie chicken ( Tympanuchus cupido ) predominantly occurs in the region, although the latter historically ranged further eastward. The Harris's sparrow ( Zonotrichia querula ) spends winter months in southern areas of

2628-512: The Great Plains is the most tornado active area in the world and is sometimes referred to as Tornado Alley . The Great Plains are part of the floristic North American Prairies province , which extends from the Rocky Mountains to the Appalachians . Although the American bison ( Bison bison ) historically ranged throughout much of North America (from New York to Oregon and Canada to northern Mexico), they are strongly associated with

2701-751: The Great Plains where they once roamed in immense herds. Pronghorn ( Antilocapra americana ) range into western areas of the region. The black-tailed prairie dog ( Cynomys ludovicianus ) is another iconic species among several rodents that are linked to the region including the thirteen-lined ground squirrel ( Ictidomys tridecemlineatus ), spotted ground squirrel ( Xerospermophilus spilosoma ), Franklin's ground squirrel ( Poliocitellus franklinii ), plains pocket gopher ( Geomys bursarius ), hispid pocket mouse ( Chaetodipus hispidus ), olive-backed pocket mouse ( Perognathus fasciatus ), plains pocket mouse ( Perognathus flavescens ), and plains harvest mouse ( Reithrodontomys montanus ), Two carnivores associated with

2774-488: The Great Plains. The ornate box turtle ( Terrapene ornata ) and great plains skink ( Plestiodon obsoletus ) occur in southern areas. Although few salamanders are strongly associated with region, the western tiger salamander ( Ambystoma mavortium ) ranges through much of the Great Plains and the Rocky Mountains, as does the Rocky Mountain toad ( Anaxyrus w. woodhousi ). Other anurans related to region include

2847-503: The High Plains) is periodically subjected to extended periods of drought ; high winds in the region may then generate devastating dust storms . The eastern Great Plains near the eastern boundary falls in the humid subtropical climate zone in the southern areas, and the northern and central areas fall in the humid continental climate . Many thunderstorms occur in the plains in the spring through summer. The southeastern portion of

2920-650: The Red, Brazos, and Colorado rivers of Texas and presents a ragged escarpment approximately 500 to 800 ft (150 to 240 m) high, overlooking the central denuded area of that state. There, between the Brazos and Colorado rivers, occurs a series of isolated outliers capped by limestone that underlies both the Llano Uplift on the west and the Grand Prairies escarpment on the east. The southern and narrow part of

2993-721: The United States, are a few states where dry farming is practiced for a variety of crops. Dryland farming is used in the Great Plains , the Palouse plateau of Eastern Washington , and other arid regions of North America such as in the Southwestern United States and Mexico (see Agriculture in the Southwestern United States and Agriculture in the prehistoric Southwest ), the Middle East and in other grain growing regions such as

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3066-490: The Western US and other regions affected by climate change for crops such as tomato and maize . In marginal regions, a farmer should be financially able to survive occasional crop failures, perhaps for several years in succession. Survival as a dryland farmer requires careful husbandry of the moisture available for the crop and aggressive management of expenses to minimize losses in poor years. Dryland farming involves

3139-716: The area of the ancient Great Plains for thousands to millions of years. The vast majority of these animals became extinct in North America at the end of the Pleistocene (around 13,000 years ago). A number of significant fossil sites are located in the Great Plains including Agate Fossil Beds National Monument ( Nebraska ), Ashfall Fossil Beds ( Nebraska ), Clayton Lake State Park ( New Mexico ), Dinosaur Valley State Park ( Texas ), Hudson-Meng Bison Kill (Nebraska), Makoshika State Park (Montana), and The Mammoth Site ( South Dakota ). Public and protected lands in

3212-483: The best use of the "bank" of soil moisture that was created by winter rainfall. Some dry farming practices include: Dry farming may be practiced in areas that have significant annual rainfall during a wet season, often in the winter. Crops are cultivated during the subsequent dry season, using practices that make use of the stored moisture in the soil. California, Colorado, Kansas, South Dakota, North Dakota, Montana, Nebraska, Oklahoma, Oregon, Washington, and Wyoming, in

3285-471: The central section, it is for the most part a dissected fluviatile plain. However, the lower lands which surround it on all sides place it in such strong relief that it stands up as a table-land, known from the time of Mexican occupation as the Llano Estacado . It measures roughly 150 mi (240 km) east-west and 400 mi (640 km) north-south. It is of very irregular outline, narrowing to

3358-419: The constant assessing of the amount of moisture present or lacking for any given crop cycle and planning accordingly. Dryland farmers know that to be financially successful they have to be aggressive during the good years in order to offset the dry years. Dryland farming is dependent on natural rainfall, which can leave the ground vulnerable to dust storms , particularly if poor farming techniques are used or if

3431-531: The encroachment of European settlers as well as economic incentives such as the fur trade, alongside the arrival of the horse and firearms from Europe pushed multiple tribes onto the Great Plains. Among those to have lived on the Great Plains were the Blackfoot , Crow , Sioux , Cheyenne , Arapaho , Comanche , and others. Eastern portions of the Great Plains were inhabited by tribes who lived at Etzanoa and in semi-permanent villages of earth lodges, such as

3504-433: The general level by 500 ft (150 m) or more and manifestly demonstrating the widespread erosion of the surrounding plains. All these reliefs are more plentiful towards the mountains in central Montana. The peneplain is no longer in the cycle of erosion that witnessed its production. It appears to have suffered a regional uplift or increase in elevation, for the upper Missouri River and its branches no longer flow on

3577-760: The great plains like the Rocky Mountain Locust (Melanoplus spretus). During the Cretaceous Period (145–66 million years ago), the Great Plains were covered by a shallow inland sea called the Western Interior Seaway . However, during the Late Cretaceous to the Paleocene (65–55 million years ago), the seaway had begun to recede, leaving behind thick marine deposits and a relatively flat terrain which

3650-501: The largest group. They rise like a large island from the sea, occupying an oval area of about 100 mi (160 km) north-south by 50 mi (80 km) east-west. At Black Elk Peak , they reach an altitude of 7,216 ft (2,199 m) and have an effective relief over the plains of 2,000 or 3,000 ft (610 or 910 m) This mountain mass is of flat-arched, dome-like structure, now well dissected by radiating consequent streams. The weaker uppermost strata have been eroded down to

3723-468: The least protected biomes. Humans have converted much of the prairies for agricultural purposes or to create pastures. Several of the protected lands in the region are centered around aberrant and uncharacteristic features of the region, such as mountains, outcrops, and canyons (e.g. Devil's Tower National Monument , Wind Cave National Park , Scotts Bluff National Monument ), and as splendid and worthy as they are, they are not primarily focused on conserving

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3796-426: The level of the plains where their upturned edges are evenly truncated. The next following harder strata have been sufficiently eroded to disclose the core of underlying igneous and metamorphic crystalline rocks in about half of the domed area. In the intermediate section of the plains, between latitudes 44° and 42° , including southern South Dakota and northern Nebraska , the erosion of certain large districts

3869-484: The line that divides the Great Plains into an area that receives 20 in (510 mm) or more of rainfall per year and an area that receives less than 20 in (510 mm). In this context, the High Plains, as well as Southern Alberta , south-western Saskatchewan and Eastern Montana are mainly semi arid steppe land and are generally characterised by rangeland or marginal farmland . The region (especially

3942-760: The more common "prairie". The Great Plains are the westernmost portion of the vast North American Interior Plains , which extend east to the Appalachian Plateau . The United States Geological Survey divides the Great Plains in the United States into ten physiographic subdivisions: Further to this can be added Canadian physiographic sub-regions such as the Alberta Plain, Cypress Hills , Manitoba Escarpment (eastward), Manitoba Plain, Missouri Coteau (shared), Rocky Mountain Foothills (eastward), and Saskatchewan Plain. The Great Plains consist of

4015-442: The mountains, the local relief is generally small. The semi-arid climate excludes tree growth and opens far-reaching views. The plains are by no means a simple unit. They are of diverse structure and of various stages of erosional development. They are occasionally interrupted by buttes and escarpments . They are frequently broken by valleys. Yet on the whole, a broadly extended surface of moderate relief so often prevails that

4088-436: The name, Great Plains, for the region as a whole is well-deserved. The western boundary of the plains is usually well-defined by the abrupt ascent of the mountains. The eastern boundary of the plains (in the United States) is more climatic than topographic . The line of 20 in (510 mm) of annual rainfall trends a little east of northward near the 97th meridian. If a boundary must be drawn where nature presents only

4161-434: The plains and prairies. United States: Canada: the Great Plains biome is found to be at the brink of collapse due to woody plant encroachment , with 62% of Northern American grassland lost to date. The first Peoples ( Paleo-Indians ) arrived on the Great Plains thousands of years ago. The introduction of corn around 800 CE allowed the development of the mound-building Mississippian culture along rivers that crossed

4234-647: The region. Other species migrate from the south in the spring and spend their breeding season on the plains, including the white-faced ibis ( Plegadis chihi ), mountain plover ( Charadrius montanus ), marbled godwit ( Limosa fedoa ), Sprague's pipit ( Anthus spragueii ), Cassin's sparrow ( Peucaea cassinii ), Baird's sparrow ( Centronyx bairdii ), lark bunting ( Calamospiza melanocorys ), chestnut-collared longspur ( Calcarius ornatus ), thick-billed longspur or McCown's longspur ( Rhynchophanes mccownii ), and dickcissel ( Spiza americana ). The prairie rattlesnake ( Crotalus viridis ) ranges throughout much of

4307-474: The river from a better graded preglacial valley by the Pleistocene ice sheet . Here, the ice sheet overspread the plains from the moderately elevated Canadian highlands far on the north-east, instead of from the much higher mountains nearby on the west. The present altitude of the plains near the mountain base is 4,000 ft (1,200 m). The northern plains are interrupted by several small mountain areas. The Black Hills, chiefly in western South Dakota, are

4380-565: The seaway had once occupied. During the Cenozoic era , specifically about 25 million years ago during the Miocene and Pliocene epochs, the continental climate became favorable to the evolution of grasslands. Existing forest biomes declined and grasslands became much more widespread. The grasslands provided a new niche for mammals, including many ungulates and glires , that switched from browsing diets to grazing diets. Traditionally,

4453-609: The seed at a depth at which sufficient moisture exists, or where it will exist when seasonal precipitation falls. Farmers tend to use crop varieties which are drought-tolerant and heat-stress tolerant (even lower-yielding varieties). Thus the likelihood of a successful crop is hedged if seasonal precipitation fails. Soil conservation : The nature of dryland farming makes it particularly susceptible to erosion, especially wind erosion. Some techniques for conserving soil moisture (such as frequent tillage to kill weeds) are at odds with techniques for conserving topsoil. Since healthy topsoil

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4526-430: The soil, rather than depending on rainfall during the growing season. Successful dryland farming is possible with as little as 230 millimetres (9 in) of precipitation a year; higher rainfall increases the variety of crops. Capturing and conservation of moisture: In regions such as Eastern Washington , the average annual precipitation available to a dryland farm may be as little as 220 millimetres (8.5 in). In

4599-405: The south. Its altitude is 5,500 ft (1,700 m) at the highest western point, nearest the mountains whence its gravels were supplied. From there, it slopes southeastward at a decreasing rate, first about 12 ft (3.7 m), then about 7 ft/mi (1.3 m/km), to its eastern and southern borders, where it is 2,000 ft (610 m) in altitude. Like the High Plains farther north, it

4672-459: The southern section owes its smoothness to the deposition of imported gravels and sands upon a previously uneven surface by the action of aggrading rivers and their outgoing distributaries. The two sections are also alike in that residual eminences still here and there surmount the peneplain of the northern section, while the fluviatile plain of the central section completely buried the pre-existent relief. An exception to this statement must be made for

4745-416: The southwest, close to the mountains in southern Colorado, where some lava-capped mesas ( Mesa de Maya , Raton Mesa ) stand several thousand feet above the general plain level, and thus testify to the widespread erosion of this region before it was aggraded. The southern section of the Great Plains, between latitudes 35.5° and 25.5°, lies in western Texas , eastern New Mexico , and western Oklahoma . Like

4818-588: The spread of grasslands and the development of grazers have been strongly linked. However, an examination of mammalian teeth suggests that it is the open, gritty habitat and not the grass itself which is linked to diet changes in mammals, giving rise to the " grit, not grass " hypothesis. Paleontological finds in the area have yielded bones of mammoths , saber-toothed cats and other ancient animals, as well as dozens of other megafauna (large animals over 100 lb [45 kg]) – such as giant sloths , horses , mastodons , and American lion – that dominated

4891-463: The storms strike at a particularly vulnerable time. The fact that a fallow period must be included in the crop rotation means that fields cannot always be protected by a cover crop , which might otherwise offer protection against erosion . Some of the theories of dryland farming developed in the late 19th and early 20th centuries claimed to be scientific but were in reality pseudoscientific and did not stand up to empirical testing. For example, it

4964-602: The subdued forms of the Wichita Mountains in Oklahoma , the westernmost member of the Ouachita system. The term "Western Plains" is used to describe the ecoregion of the Great Plains, or alternatively the western portion of the Great Plains. In general, the Great Plains have a wide range of weather, with very cold and harsh winters and very hot and humid summers. Wind speeds are often very high, especially in winter. The 100th meridian roughly corresponds with

5037-464: The surface of the plain, but in well graded, maturely opened valleys, several hundred feet below the general level. A significant exception to the rule of mature valleys occurs, however, in the case of the Missouri, the largest river, which is broken by several falls on hard sandstones about 50 mi (80 km) east of the mountains. This peculiar feature is explained as the result of displacement of

5110-590: The table-land, called the Edwards Plateau , is more dissected than the rest, and falls off to the south in a frayed-out fault scarp. This scarp overlooks the coastal plain of the Rio Grande embayment . The central denuded area, east of the Llano, resembles the east-central section of the plains in exposing older rocks. Between these two similar areas, in the space limited by the Canadian and Red Rivers, rise

5183-530: The term prairie is more commonly used in Canada, and the region is known as the Canadian Prairies , prairie provinces or simply "the prairies". The North American Environmental Atlas , produced by the Commission for Environmental Cooperation , a North American Free Trade Agreement (NAFTA) agency composed of the geographical agencies of the Mexican, American, and Canadian governments, uses

5256-532: Was alleged that tillage would seal in moisture, but such "dust mulching" ideas are based on what people imagine should happen, or have been told, rather than what testing actually confirms. In actuality, it has been shown that tillage increases water losses to evaporation. The book Bad Land: An American Romance explores the effects that this had on people who were encouraged to homestead in an area with little rainfall; most smallholdings failed after working miserably to cling on. Dry farming depends on making

5329-577: Was not generally used before the early 20th century. Nevin Fenneman's 1916 study Physiographic Subdivision of the United States brought the term Great Plains into more widespread usage. Before that the region was almost invariably called the High Plains, in contrast to the lower Prairie Plains of the Midwestern states . Today the term " High Plains " is used for a subregion of the Great Plains. The term still remains little-used in Canada compared to

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