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A variety of natural environmental conditions afford a country many options for different land uses and kinds of economic development. Crops, for example, are adapted to different types of climate and soil. Because of the environmental diversity in the United States, any crop in the world can be grown somewhere in the country.

The United States is blessed with some of the world’s best farmland. Vast areas of flat land with good soil and adequate moisture provide the foundation on which the world’s most productive agricultural economy was developed. From the very beginning of European settlement, people were drawn to good farmland. Fertile alluvial （stream-deposited） soils drew settlers inland across the broad Atlantic and Gulf coastal plains and inland along river valleys and into broad basins. Different parts of the United States are better for raising different crops or products. The Great Plains （grasslands） grow large amounts of wheat, barley, corn, and other grains. In some of the drier desert areas of the West, where crops cannot be easily grown, ranchers graze cattle and other livestock. Crops like potatoes grow best in cooler climates, so they are grown in mountainous areas where it stays cooler longer in the spring.

Farming Regions of the United States

For management purposes, the U.S. Department of Agriculture divides the United States into 10 major farm production regions. These regions differ from each other in terms of soil,slope of the land, climate, distance to market, and storage facilities.

The Northeast and the states near the Great Lakes are where most of the country’s milk is produced. The climate and soil is good for growing grains that cattle need. The Appalachia region is a major tobacco-producing area. It is also well known for cattle and hog production, dairy farming, and peanuts. The Southeast region is used for raising beef and farming fruit, vegetables, peanuts, citrus fruit, winter vegetables, sugar-cane, and cotton.

The Delta region grows soybeans, cotton, rice, corn, and sugarcane. It is also an important area for livestock production. The Corn Belt has an abundance of rich soil and a good climate for farming. This region produces corn, wheat, soybeans, dairy products, cattle, hogs, and feed grains. The Northern and Southern Plains produce the majority of the nation’s winter and spring wheat. They also harvest other grains, hay, and cotton and are involved in dairy farming （milk production）. The Mountain region is largely used for grazing cattle and sheep. Wheat is also grown there, though, as well as hay, sugar beets, fruits, potatoes, and other vegetables in the irrigated valleys. The Pacific region specializes in wheat, potatoes, fruit, cotton, cattle, and dairy farming. Hawaii is well known for growing pineapples and sugarcane. Alaska has many greenhouse/nursery farms and also produces dairy products.

There are many agricultural crops produced in the United States, and different commodities（items） are produced in different parts of the country. The United States is fortunate to have a large variety of crops that can be grown, such as fruits, vegetables, grains, hay, cotton, tobacco, sugar, beans, peas, lentils, flowers, and landscaping plants and trees, just to name a few.

The alternating layers of hard and soft rocks of the Gulf Coastal Plain have a direct impact on land use. On the Selma chalk the Black Belt of Alabama and Mississippi is formed.“Black” refers to the color of the soil, not to the color of the people who live there, although the confusion is perhaps not surprising given the development of large plantations in the Black Belt during the mid-19th century. The Black Belt, as well as a similar limestone lowland on black soils known as the Jackson Prairie, were stretches of fertile soil in a region where soils were generally poor.

Black Belt plantations were transformed from the highly centralized operations worked with slave labor that were typical before the Civil War to a more dispersed system based on tenancy thereafter. From 1870 until the mid-20th century, the Black Belt was a maze of cotton fields dotted with tenant cabins and subsistence garden patches.

Between southern Ohio and eastern Nebraska lies North America’s most productive agricultural region, the Corn Belt. Although agriculture is more intensive in some irrigation districts of the West, no other large area can compare with the Corn Belt’s productivity. The Corn Belt is also among the oldest of the continent’s agricultural regions. It emerged rapidly in the process of westward settlement expansion during the mid-19th century when, in barely four decades, corn-livestock agriculture advanced from the Scioto Valley of Ohio to the plains of Nebraska.

The term Corn Belt refers not only to a region where corn is grown but also to the primary use made of the crop, fattening meat animals for market. Automobile fuel and soft-drink sweeteners are among the many products made from corn today, but historically corn has been consumed by hogs and cattle on the farms where it is grown. Despite the new industrial and food uses and the substantial exports of corn to other countries in recent decades, livestock still consume the bulk of the annual corn crop, which is measured in the billions of bushels.

Tobacco has long been one of the most labor-intensive crops grown on American farms. Although its introduction into the Tidewater colonies of Virginia and Maryland antedated the use of slaves, most tobacco was grown plantation-style with slave labor until the 1860s. Large landholdings remained after the Civil War, but the practice thereafter was to rent or lease land to tenant farmers and sharecroppers. Each tenant had a piece of ground, usually forty acres, with a crude dwelling （owned by the landlord）. The tenant family had a garden, a cow, a few hogs, and a mule. Nearly all of their rented land had to be used for crops, including perhaps eight acres of tobacco, four of cotton, and twenty or more acres of corn and hay for feed. Between one-fourth and one-half of the crop went to the landlord.

Water, one can argue, is the resource most essential to life, yet water-related problems loom on the horizon. A growing population, particularly in the water-deficient Southwest, has pushed available water supplies to their limit. Water pollution is a problem in many areas, including the Great Lakes, many smaller water bodies, and rivers in most areas of the country. Groundwater stores are being polluted in some areas and critically depleted in others.

The United States is the only country bordered by three of the world’s oceans—thePacific, the Atlantic, and the Arctic. （Technically, Russia faces on the Baltic Sea, not the Atlantic Ocean.） This gives the country a tremendous advantage in many ways. Politically, oceans do not “belong” to anyone; hence, they serve as a buffer against potentially hostile neighbors. Economically, they are the source of countless marine resources, scenic beauty（resulting in increased property values）, and shipping access to much of the world. Physically, oceans moderate temperatures and serve as the source of atmospheric moisture. With possible continued warming of Earth’s atmosphere, the Arctic Ocean may become a major focal point of global navigation. In the absence of thick sea ice, ships could easily pass between Europe, Asia, and North America.

Most lakes, therefore, are in the northeastern section of the country and north of the Ohio and Missouri rivers. Elsewhere, in the Southeast and the West, most “lakes” are actually reservoirs, water bodies formed behind dams. The Great Lakes form the world’s largest system of freshwater. In fact, Lake Superior is the world’s largest freshwater lake by surface area. Water from the Great Lakes reaches the Atlantic Ocean through Canada’s St. Lawrence River. For a half century, ships have been able to pass between the Great Lakes and the Atlantic by way of the St. Lawrence Seaway.

The major river system in the United States is that formed by the Mississippi and its two major tributaries, the Ohio and Missouri rivers. This giant network drains about 41 percent of the 48-state area, including all or part of 31 states （and two Canadian provinces）. The combined Missouri-Mississippi River is about 3 700 miles （5 970 kilometers） long, a distance surpassed only by the Nile and Amazon rivers. Barges can navigate the rivers upstream to Minneapolis-St. Paul, Minnesota; Pittsburgh, Pennsylvania; and Sioux City, Iowa. New Orleans, Louisiana, located near the mouth of the Mississippi, was one of the nation’s leading seaports before Hurricane Katrina’s devastating blow in 2005.

In the Southwest, the Rio Grande and Colorado River flow southward across desert landscapes. Both streams are of far greater importance than their relatively small volume of water might suggest. In fact, millions of people, huge cities, and billions of dollars in agricultural production depend on their flow. The Rio Grande flows from the Colorado Rockies, through central New Mexico, and into Texas, where it forms the border between the United States and Mexico. It is dammed in three locations, is vital to regional agriculture, and is often dry along much of its lower course.

In the Pacific Northwest, the mighty Columbia and its chief tributary, the Snake River, produce huge amounts of hydro-electric energy. They are also the source of water for irrigationand domestic use and for important recreational resources. Alaska’s Yukon River is a large stream but is of little economic significance.

Groundwater is water deposits stored in an aquifer, the upper limit of which is the water table. In arid regions, an aquifer may be nonexistent or may lie more than 1 000 feet （300 meters） below the surface, as is the case throughout much of the desert Southwest. Groundwater is tapped by wells, although in some places it reaches the surface through springs. Throughout much of the country, both the quality and the quantity of groundwater deposits are in sharp decline.

When the pilgrims arrived in America in 1620, the European settlers cut down many of the forests in order to farm. Within 200 years, very little forested area was left. Then, in the 1800s, new industries were invented and large cities began to develop. Many of the existing farms were abandoned, which were then, fortunately, able to revert back to forests.

Forestry, papermaking, and wood-product manufacturing are the most important industries of the Gulf Coastal Plain, just as forests are by far the most common land cover in the region. These are the famed “piney woods” of the Lower South. They are regarded by some as the natural vegetative growth in this region of sandy, acidic soils. Although such limiting conditions generally favor growth of pines （and other softwoods） rather than many hardwoods, the piney woods appear to have evolved as a regional forest type with a good deal of human influence as well.

Southern pine species, such as the longleaf, loblolly, and slash pine varieties, are more resinous than their northern counterparts and were long exploited mainly for their oleoresins in the manufacture of turpentine, paint, tar, and gum. They were considered unsuitable for plywood manufacture until a southern pine plywood mill was constructed at Fordyce, Arkansas, in the 1940s. A wide variety of both hardwoods and softwoods are now used to produce wallboard, paneling, plywood, flooring, fiberboard, and other construction materials. These industries are scattered widely across the Coastal Plain, as are numerous paper mills, which manufacture stock for products ranging from cardboard cartons and paper bags to copier paper.

According to the Mineral Information Institute¹², many things have changed in thenonfuel minerals industry over the past 100 years alone. At the beginning of the 1900s, some minerals and metals industries were well established, such as those for copper, gold, lead, lime, and salt; some industries were just beginning, such those for aluminum and lithium; and some materials, such as germanium, magnesium, and titanium, had not yet been commercially produced.

There are two general classes of resources: renewable and non-renewable. A renewable resource is a resource that can be replenished. It is a resource that can be replaced by natural ecological cycles, Earth system cycles, and good management practices. The opposite of this is a nonrenewable resource—a resource that cannot be replenished （once it is gone, it is gone for good）.

The Appalachian Coal Field

The Appalachian Coal Field produces nearly half of all bituminous coal mined in the United States. The coal field is practically coextensive with the Appalachian Plateau south of the limit of carboniferous rock formations along the Pennsylvania-New York border. Although Wyoming is now the leading coal-producing state, West Virginia ranks a close second. The increased demand for coal to meet industrial, transportation, and heating needs created a westward-moving frontier of coal mining in the Appalachian Plateau during the late 19th century. Periodic spurts of national economic growth during the 1870s and 1880s led to an ever-widening search for new veins of bituminous coal. Western Pennsylvania, West Virginia, and eastern Kentucky were the foci of these new developments well into the 20th century.

Colorado Plateau Resources

The Colorado Plateau is a region of multicolored sandstones, shales, and limestones and of high plateaus, deep canyons, and flat-topped mesas, stretching from the Rocky Mountains to the Wasatch Range. Coal, oil shale, and natural gas are found in the Colorado Plateau’s almost flat-lying sedimentary strata. Large quantities of bituminous coal now are mined on the Black Mesa of northern Arizona to provide energy for local electric-power generation. Oil shale was a resource thought ready for development during the oil-short 1970s, and plans for its exploitation helped stimulate an economic boom in Denver, but the industry collapsed when oil prices dropped. Natural gas produced in the Piceance Basin of Colorado supplies part of the energy needs of southern California. Producing oil wells are scattered around the major gas and oil-shale deposits, but the region’s oil production is small.

The Colorado Plateau also is the major source of uranium in the United States. Colorado’s19th-century gold miners were troubled by a black, tar-like substance that adhered to their mining tools. It was pitchblende, and they discarded it as a nuisance. The most promising source of radium in the United States was carnotite, a yellowish, uranium-bearing rock abundant in the Colorado Plateau.

The Iron and Steel Industry

The largest steel mills of the Lower Great Lakes region are integrated mills, meaning that they produce molten pig iron from iron ore and then, with the addition of alloys, produce steel from the molten iron. Cast, rolled, and forged steel shapes are the mills’ end products. The manufacture of pig iron requires quantities of iron ore, coke, and limestone. Coke is an intermediate product, created through the heating of high-volatile bituminous coal in airtight ovens, a procedure that drives out gases and tar and makes a substance that is 90 percent pure carbon.

Minerals Are Nonrenewable

Mineral resources make modern life possible. Minerals are nonrenewable, however. Although the processes that created minerals are still actively occurring today, it takes hundreds, thousands, even millions of years in some cases for them to form. It is important to use these nonrenewable resources in a sustainable way to ensure that the benefit of using those resources now is balanced with the importance of saving those resources for future generations.

Minerals can be classified according to their chemical composition and crystal structure and can be subdivided into 10 types of classes: （1） elements, （2） sulfides, （3） halides,（4） oxides, （5） carbonates, （6） sulfates, （7） phosphates, （8） silicates, （9） organics, and（10） mineraloids.

1. the Commonwealth of Puerto Rico波多黎各自治邦，是美国在加勒比海地区的一个自治领地。

2. Virgin Islands of the Onited States美属维尔京群岛，是维尔京群岛的一部分，它是美国在加勒比海地区的一个非建制的属地，原为丹麦属地，被美国购得。

3. islands of American Samoa美属萨摩亚，是美国在南太平洋的一个非建制的属地，又称东萨摩亚，面积约为199平方公里。

4. Guam关岛，又称the Territory of Guam，是美国位于西太平洋的一个非建制的属地，美军基地占地约为全岛面积的四分之一。

5. Colorado Plateau科罗拉多高原，是位于美国西南部的沙漠高原，横跨犹他州、科罗拉多州、新墨西哥州和亚利桑那州。

6. Arizona’s Grand Canyon National Park and Utah’s Bryce Canyon, Zion, and Arches

national parks and Cedar Breaks National Monument 美国的风景名胜区：大峡谷国家公园、布莱斯峡谷国家公园、锡安国家公园、拱石国家公园和塞达布雷克国家纪念区。

7. Aleutian Islands阿留申群岛，属美国阿拉斯加州，位于太平洋和白令海之间，包括十四个大岛和众多小岛，战略位置重要，建有美国海军和空军基地。

8. Grand Teton National Park大蒂顿国家公园，位于怀俄明州，因蒂顿山脉的最高峰大蒂顿峰而得名。

9. Glacier National Park冰川国家公园，位于落矶山脉北部，建于1910年，位于美国蒙大拿州北部与加拿大的英属哥伦比亚省和亚伯达省接壤之处。1932年与加拿大亚伯达省的沃特顿湖国家公园（Waterton Lakes National Park）联合成立了沃特顿-冰川国际和平公园（Waterton- Glacier International Peace Park），是全世界第一个国际和平公园。

10. Galveston Bay加尔维斯顿湾，它是美国德克萨斯州东南沿海墨西哥湾的一部分，玻利瓦尔（Bolivar）半岛和加尔维斯顿岛使之与墨西哥湾相隔。

11. total fertility rate总和生育率，也称总生育率，简称TFR，是指某国家或地区的妇女在育龄期间，每个妇女平均的生育子女数。

12. Mineral Information Institute矿产信息学会，是美国的一家教育机构，主要致力于从采矿业视角对儿童进行矿产品及其开采等知识教育。

I. Fill in the blanks according to the text.

1. United States of America, popularly referred to as the United States or as America, a federal republic on the continent of North America, consisting of 48 contiguous states and the noncontiguous states of ______________.

2. The largest states in area are ________ at 1 717 854 sq km （663 267 sq mi）, followed by Texas, and California. The smallest state is ___________, with an area of 4 002 sq km（1 545 sq mi）. The state with the largest population is __________ （36 553 215, 2007 estimate）, followed by Texas, and New York.

3. Hawaii’s highest peak, ___________, rises about 20 000 feet （6 096 meters） from thePacific floor and reaches an elevation of 13 796 feet （4 205 meters） above sea level.

4. _______________, central California’s towering “backbone”, is an excellent example of an uplifted fault block range.

5. Some basins contain large saltwater bodies, such as Utah’s _____________ and southern California’s ______________.

6. ______________ is the science devoted to the statistical study of the human population.

7. Today, in fact, nearly __________ percent of all Americans reside in urban centers（communities with more than 2 500 residents）.

8. The Sun Belt of the South and Southwest, an area that stretches from ________ to__________.

9. States that produce lots of fruits and vegetables are _________, ___________, and__________, not only because of their climates but also because they have longer growing seasons.

10. ___________ and the states near _________ are where most of the country’s milk is produced.

II. Define the following terms.

1. United States of America

2. “America the Beautiful”

3. the Colorado Plateau

III. Questions for discussion.

1. Which area does America’s “breadbasket” refer to? Explain the reasons.

2. What problems does an aging population create?

3. Why have millions of people fled the Rust Belt or Snow Belt of the Northeast and have moved to the warmer Sun Belt of the South and Southwest?

4. How is the Black Belt of Alabama and Mississippi formed? What does “black” mean in this term?

5. How many types can minerals be classified according to their chemical composition and crystal structure?