General situation of the development of American economic zone

The United States has become a highly developed country in agricultural regional specialization in the world, with nine major agricultural regions (belts) formed by specialization:

(1) The cheese belt includes the northeast and lakeside. Located in the north, it belongs to the continental temperate coniferous forest climate, and the soil is relatively barren. Under this condition, it is not suitable for planting grain, but it is very beneficial to the growth of pasture and suitable for the development of animal husbandry. It is close to the industrial zone, with a population of 1/2, and it is a huge milk and dairy product consumption market. In addition, immigrants from western Europe and northern Europe have traditional experience and skills in raising cows and planting pasture. Therefore, this area has gradually developed into a specialized production area of pasture cheese centered on milk production, mainly engaged in the production of intensive agricultural and livestock products that are not convenient for long-distance transportation.

(2) Corn Belt This area is located in the south of the cheese area of pasture, between 40 and 45 north latitude, mainly including Iowa, Illinois, Indiana and other states. This is a low-lying and fertile grassland chernozem with deep soil layer, high temperature and high humidity in spring and summer, and annual precipitation of 520 ~ 650 mm. This natural condition is extremely beneficial to the growth and development of corn. At present, the corn produced here has accounted for 3/4 of the total corn output in China and has become a world-famous corn specialization area. In addition to planting corn, pasture and wheat are also planted in rotation. In recent years, more and more soybeans have been planted in rotation and become the soybean producing area in the country. Use these agricultural products as concentrated feed to raise pigs and cattle, forming a combination of agriculture and animal husbandry. Although this zone is based on corn, its commercial significance lies in animal husbandry. Therefore, corn belt is often called corn livestock belt or corn soybean belt.

(3) The wheat belt is located in the west of the Central Plain (Great Plains), which mainly includes five states: South and North Dakota, Montana, Kansas and Oklahoma. The terrain here is flat, the soil is fertile, and the winter is long and cold. The northern part is suitable for the growth of spring wheat, and the southern part can be planted with winter wheat. This area belongs to semi-arid area, with annual precipitation of 350 ~ 650 mm, most of which is concentrated in April ~ August of crop growth period. The dry climate in autumn is conducive to a bumper harvest of grain. In addition to mainly planting wheat, it also rotates with pasture, and there are natural pastures nearby, so it is often combined with raising beef cattle. Using railways and convenient water transportation conditions, the grain produced in this area is often transported and sold to the Far East industrial zone and coastal areas.

④ The cotton belt is located in the southeast of the United States. From the Atlantic coast in the east to the eastern part of Texas in the west, it is a famous old cotton-growing area in history. The average temperature in summer is above 26 ~ 27℃, with more precipitation in spring and summer and drier autumn, which is very beneficial to the growth, maturity and harvest of cotton, so it has long been a concentrated cotton producing area in the United States. However, since the 20th century, great changes have taken place in the old cotton areas due to technological progress, soil erosion in the south and the spread of pests. Especially after World War II, the cotton belt gradually disintegrated and pushed westward, forming some new cotton areas. However, the primitive agriculture here tends to be diversified and begins to evolve into multi-sector agriculture dominated by animal husbandry. At present, the cotton producing areas in the United States can be roughly divided into three regions: the eastern region, including Alabama, Georgia and South and North Carolina. Before World War II, it once accounted for more than 1/4 of China's total cotton output. Now, a large area of cotton fields has been planted with soybeans and pasture, and the beef and chicken industry is very developed, which has become an important part of the "broiler belt". In the central region, that is, the lower reaches of the Mississippi River and the delta agricultural area, the cotton yield in Mississippi is the largest, and the production of rice and sugarcane is developing rapidly at present. The western belt includes two states in the western plain, among which Texas with irrigation conditions is the state with the largest cotton field and the largest yield in China. After World War II, beef cattle breeding and sorghum planting in this area developed rapidly. Although the old cotton belt in the United States has been dispersed at present, it is no longer a continuous belt distribution. However, due to many social and economic characteristics, especially in agriculture, such as the destruction of the natural environment, the low level of productivity and the large proportion of blacks in the population, people still call this area the cotton belt. At present, the key distribution areas of cotton in the United States have shifted to the west, and 70% of the output is concentrated in Texas, New Mexico, Arizona and California.

(V) Mountainous grazing and irrigated agricultural areas The vast western highlands and mountains of the United States, mainly the Rocky Mountains, account for more than 1/3 of the country, with poor land and arid climate. Due to the lack of water resources, vast land and sparsely populated areas, natural pastures are used to develop into large-scale specialized grazing areas. Its northern part is a seasonal pastoral area, and its main crops are wheat, beans and sugar beet. The south is a perennial grazing area. Since the war, it has rapidly developed into a highly intensive irrigated agricultural area, growing cotton and other crops. Cotton production in irrigated areas of Arizona is about twice the national average.

(6) The wheat, forest and animal husbandry areas in the northern part of the Pacific coast are located in the north of latitude 40, with mild and rainy winters, the highest temperature in Leng Yue is above 0℃, and the annual precipitation is 65,438 000mm mm. The mountainous area here is developed late, so forestry and animal husbandry should be developed; Wheat and temperate fruits are grown in the valley.

(7) Fruits, vegetables and irrigated agricultural areas in the south of the Pacific coast. It is mild and rainy in winter and hot and dry in summer, belonging to the Mediterranean climate zone. Develop irrigated agriculture, produce vegetables, grapes and fruits in large quantities and supply them to all parts of the country. The output of commercial vegetables in California accounts for more than 1/3 of the whole country.

(8) The mixed agricultural zone (i.e. the comprehensive agricultural management zone or the comprehensive tobacco and agricultural management zone) is located in the south of the corn belt and the north of the cotton belt, mainly planting wheat, corn and tobacco.

(9) Subtropical crop areas are located along the Gulf of Mexico, and the climate is hot and rainy all year round. Planting citrus, sugar cane, rice and other subtropical crops and early fresh vegetables for the whole country.