At the beginning of the 20th century it took a large team of farmers and field hands weeks to plant and harvest one crop, and it took four farmers to feed 10 people. Today, machinery allows the entire midwestern corn crop to be planted in 10 days and harvested in 20; and one U.S. farmer can produce enough food to feed 97 Americans and 32 people in other countries.
Twentieth century engineering has made the difference. The tractor, the reaper, the combine, and hundreds of other machines gave farmers the mechanical advantage they had long needed to ease their burdens and make their lands truly profitable. Agricultural mechanization enormously increased farm efficiency and productivity.
Engineering began to affect the farmer late in the 19th century, with steam-powered tractors and various tools for drilling seed holes and planting. Still, most field work was done with hand tools like the spade, hoe, and scythe, or with hand- or animal-driven plows. A farmer's day was labor-intensive, beginning well before sunrise and ending at sunset.
Mechanization did not advance rapidly until the 20th century, with the advent of the internal combustion engine. As the chief power source for vehicles, it began replacing both horses and steam for planting, cultivating, and harvesting equipment. It made the evolution of the tractor possible, and led to sweeping changes in agriculture.
The number of tractors in developed countries increased dramatically, especially in the United States. In 1907, some 600 tractors were in use; by 1950, the figure had grown to almost 3,400,000. Major changes in tractor design include the power takeoff, the all-purpose or tricycle-type tractor, which enabled farmers to cultivate planted crops mechanically; rubber tires, which facilitated faster operating speeds; treads that could negotiate soft soil without getting stuck; and the switch to four-wheel drive and diesel power in the 1950s and 1960s, which greatly increased the tractor's pulling power. More recent innovations have led to the development of enormous tractors that can pull several gangs of plows while electronic systems monitor or control almost all of the power functions.
A large number of fatal injuries from tractors tipping over led to the design of rollover bars. They became commercially available in 1956 and later evolved into cabs, which provide a protective zone for operators, noise control, and a comfortable environment.
Engineering design for planting and harvesting was hampered by the wide variety of crops, all with different shapes and consistencies (e.g., corn, soybeans, wheat, cotton, and tomatoes). Nevertheless, an amazing array of innovations peppered the century, such as tractor-attachable cultivators and harvesters. Self-tying hay and straw balers arrived in 1940 along with a spindle cotton picker. Shielded corn-snapping rolls were developed in 1952, and rotary and tine separator combines were introduced in 1976, each reducing labor significantly.
A major necessity on many farms is a way to control soil erosion and reduce the time and energy to prepare seedbeds. The development of chisel and disc tillage tools and no-till planters in the 1970s and 1980s solved these problems. Even in the 1940s, sweep plows undercut wheat stubble to reduce wind and water erosion and conserve water.
At the turn of the century there were about 16 million acres of irrigated land in the United States. Today there are over 62 million acres, made possible by various types of mechanized irrigation, such as gated-pipe, side-roll, big-gun, or center-pivot machines. These machines can automatically irrigate areas from 150 to 600 acres, and can also apply some fertilizers and pesticides.
Over the century, the average amount of labor required per hectare to produce and harvest corn, hay, and cereal crops gradually fell more than 75 percent. In the process, a massive shift from rural to urban life took place. This shift began to have a lasting impact on the nature of work, the consumer economy, women's roles in society, and even the size and nature of families. For women, farm mechanization freed them from many of the time-consuming household chores required to support a large family and any helpers hired to work the farm. They no longer had to grow, prepare, preserve and cook the massive quantities of food needed on a daily basis. Mechanization meant empowerment for women, who soon became major consumers as the American economy gradually changed from the barter system to cash.
Mechanization also meant empowerment for men. Traditionally, farm ownership and responsibility shifted from generation to generation; roles were set at birth, and choosing a career was not an option. Mechanized farms meant less people were needed to work them, and that brought a different kind of personal freedom for many.
Farm mechanization has almost entirely replaced human and animal power in developed nations, and is now transforming agriculture in many developing areas. In combination with other improvements in crop techniques and food processing, it has significantly altered food production and distribution throughout the world.
Bringing this standard to all the countries of the world is a major goal of the next century, and an attainable goal, according to the Food and Agricultural Organization (FAO) of the United Nations. In a recent report, the FAO noted that world agricultural production, stimulated by improving technology, reached a record high in the mid-1990s - good news for the 6 billion people who inhabit the planet.
