The growth of agriculture

Agriculture is the art and science of cultivating the soil, growing crops, and raising livestock. It includes the preparation of plant and animal products for people to use and their distribution to markets.

Before agriculture became widespread, prehistoric people spent most of their lives hunting animals and gathering wild plants. Then, about 11,500 years ago, people gradually learned how to cultivate plants for food use and settled down to a life based on farming. Scholars are unsure why this shift to farming took place, but it may have occurred because of climate change. The earliest crops were most likely rice, corn, or similar types of cereals. Around the same time, people also began herding and breeding animals. Sheep and goats were probably domesticated first, followed by cattle and pigs. Eventually, people started keeping animals such as oxen for ploughing and transportation.

Agriculture enabled people to produce a surplus of food, which could be eaten when crops failed or exchanged for other goods. This exchange was how trade began, and in turn, it allowed people to work at other tasks unrelated to farming. Agriculture also kept formerly nomadic people near their fields and led to the establishment of permanent villages, which became linked through trade. This development was so successful in some areas that cities emerged, and eventually entire civilizations arose. The earliest of these developed near the Tigris and Euphrates rivers in Mesopotamia (now Iraq) and along the River Nile in Egypt, eventually spreading to Europe, Asia, and beyond.

For thousands of years, agricultural development was very slow. Farmers cultivated small plots of land by hand, using axes to clear away trees and sticks to break up and till the soil. Over time, improved farming tools of bone, stone, bronze, and iron were developed. Around 7,500 years ago, farmers in Mesopotamia created simple irrigation systems. By channeling water from streams onto their fields, they were able to settle in areas once thought to be unsuited to agriculture. In Mesopotamia and later in Egypt, people organized themselves and worked together to build irrigation networks. As the Roman Empire expanded, the Romans adapted the best agricultural methods of the peoples they conquered. They even wrote manuals about the farming techniques they observed in Africa, Asia, and Europe. By 2,000 years ago, much of the world’s population was reliant on agriculture.

In medieval times, European farmers adopted an open-field system of planting in which one field would be planted in spring, another in autumn, and one would be left unplanted, or fallow. This system preserved nutrients in the soil, thus increasing crop production. Later, in the 15th and 16th centuries, explorers traveling to Africa, Asia, and the Americas began to introduce new varieties of plants into Europe. From the Americas, for example, they brought back agricultural products such as potatoes, tomatoes, maize, and beans, which eventually became staple crops and an integral part of the European diet.

A period of major agricultural development began in the early 1700s in Great Britain and northern Europe. One of the most important of these developments was the horse-drawn seed drill, invented in England by Jethro Tull. Until that time, farmers sowed seeds by hand. Tull’s invention made rows of holes for the seeds and dropped them into the holes, greatly improving the speed and efficiency of the process. By the end of the 18th century, seed drilling was widely practiced in many countries across Europe.

Along with new machines, there were several other important advances in farming methods. By selectively breeding their livestock—deliberately breeding animals with desirable qualities from chosen parent animals—farmers increased both the size of their herds and the productivity of their livestock. An early example of this is the Leicester sheep, selectively bred in England for its quality meat and long, coarse wool. Then, in Austria in 1866, a monk and science teacher named Gregor Mendel published his studies of heredity, which were the first to show how traits are passed from one generation of plants to the next. Mendel is widely recognized as the founder of the science of genetics, and his experiments paved the way for the selective breeding of plants and the improvement of crops through genetics.

Another major agricultural breakthrough came from the field of chemistry. For thousands of years, farmers had relied on natural fertilizers—materials such as animal or bird waste, wood ash, or ground bones—to replenish or increase nutrients in the soil. Then, in the early 1800s, scientists discovered which elements were most essential to plant growth: nitrogen, phosphorus, and potassium. This led to the manufacture of chemical fertilizers based on nitrates and phosphates, which greatly increased crop yields. With the population of Europe doubling during the 1800s—from around 200 million at the beginning of the century to around 400 million at its end—farming had finally become big business.