Agriculture originated when humans learned to domesticate plants and animals for their use. Agriculture is defined as the deliberate modification of Earth’s surface through cultivation of plants and rearing of animals to obtain sustenance or economic gain. The word cultivate means “to care for,” and a crop is any plant cultivated by people.
Key Issue 2: Where Did Agriculture Originate?
Agriculture is deliberate modification of Earth’s surface through cultivation of plants and rearing of animals to obtain sustenance or economic gain. Agriculture emerged when humans domesticated plants and animals for their use. Cultivate means “to care for,” and a crop is any plant cultivated by people.
Invention of Agriculture Agricultural activity began before recorded history, making determinations of its origins difficult. Scholars have established a logical series of events based on fragments of information about ancient agricultural practices and environmental conditions of the past.
Hunters and Gatherers Prior to agriculture, all humans probably obtained food through hunting for animals, fishing, or gathering plants. Groups of hunters and gatherers generally kept their numbers below 50, as a larger number would quickly exhaust the available resources within walking distance. Groups regularly traveled, with the direction and frequency of migration determined by the movement of game and the seasonal growth of plants at different locations. Men hunted game or fished, while women gathered berries, nuts, and roots. This division of labor is evidenced by archaeological and anthropological findings.
Only an estimated quarter-million people of the world’s population still survive by hunting and gathering.
Agricultural Revolution The process of humans domesticating plants and animals and no longer relying on hunting and gathering is known as the agricultural revolution. Researchers believe that the agricultural revolution began circa 8000 B.C.E., when the pace of population growth increased rapidly. The domestication of plants and animals provided humans larger and more stable sources of food, allowing more people to survive. Environmental and cultural factors likely contributed to the agricultural revolution. Environmental factors, such as climate change and the ending of the last ice age, resulted in a wider spatial distribution of humans, animals, and plants. Cultural factors, such as the accidental and deliberate experimentation with the production of plants, likely reflected a preference for living in a fixed place rather than as nomads.
Agricultural Hearths The planting of crops and domestication of animals originated in multiple hearths around the world during different eras. Hearths include Southwest Asia, East Asia, Central and South Asia, sub-Saharan Africa, and Latin America.
Southwest Asia Around 10,000 years ago, barley, wheat, lentil, and olives were cultivated in Southwest Asia. Between 8,000 and 9,000 years ago, animals such as cattle, goats, pigs, and sheep were domesticated in this hearth. From this hearth, cultivation diffused west to Europe and east to Central Asia.
East Asia Rice is thought to have been domesticated more than 10,000 years ago, along the Yangtze River in eastern China.
Central Asia and South Asia Chickens are theorized to have diffused from South Asia round 4,000 years ago. The horse is speculated to have been domesticated in Central Asia, and may be associated with the diffusion of the Indo-European language.
Sub-Saharan Africa Sorghum was domesticated in central Africa approximately 8,000 years ago, and yams may have been domesticated in this hearth even earlier. Millet and rice may have been domesticated here independently of East Asia.
Latin America Mexico is considered to be the hearth for the diffusion of beans and cotton, and Peru for the potato. Maize (corn) is hypothesized to have emerged from the two hearths independently, diffusing north and south.
The transfer of plants and animals between the Western Hemisphere and Europe, as a result of European colonization and trade is known as the Columbian Exchange.
Subsistence & Commercial Agriculture The key differences in agricultural practices are between those in developing countries and those in developed countries. In developing countries most people work in subsistence agriculture, which is the production of food primarily for consumption by the farmer’s family. Commercial agriculture, the production of food primarily for sales off the farm is found in developed countries. A cash crop is a crop grown for sale rather than the farmer’s own use. Commercial agriculture differs from subsistence agriculture in three ways: the percentage of farmers in the labor force, the use of machinery, and farm size.
Farmers: Fewer Grow More In developed countries, roughly 3 percent of the workforce is engaged directly in farming, in contrast to the 35 percent of workers engaged in farming in developing countries. Both push and pull factors have contributed to the decline in the number of farmers in the United States. People were pushed away from farms by lack of opportunity to earn a decent income and at the same time they were pulled to higher-paying jobs in urban areas.
Technology: Agriculture’s Game Changer In developed countries commercial farmers rely on machinery whereas subsistence farms use hand-tools and animal power. From the invention of the iron plow in 1770, inventions made farming less dependent on human and animal power. Research conducted in university laboratories and elsewhere generates new fertilizers, herbicides, hybrid plants, animal breeds, and farming practices engineered to increase crop yields and produce healthier animals. GPS devices have allowed farmers to assist in the precise planting of seeds and for spreading different types and amounts of fertilizers. On ranches, GPS can be used to monitor the locations of cattle and tractors. Satellite imagery is a valuable resource for measuring crop progress, as well.
Farm Size: Is Bigger Better? The average farm is relatively large in commercial agriculture. Combines, pickers, and other machinery perform most efficiently at very large scales and their considerable expense cannot be justified on a small farm. Farmers spend hundreds of thousands of dollars to buy or rent land and machinery before beginning operations. Commercial farmers frequently expand their holdings by renting nearby fields. Most commercial farms in the United States today are family owned and operated. The amount of land devoted to agriculture has increased in the United States primarily due to irrigation and reclamation. The expansion of urban areas into formerly rural areas is a challenge faced today.
9.2
Irrigation
Moving water to where you need it
Yield
The amount of an agricultural product produced in an area of cultivation