Agricultural machinery

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One of the truly elemental needs for humans is the need for food. Hence, agriculture has been an essential human activity almost from the beginning, and is something that has often driven the development of technology and machines.

Doubtless, the first man to turn from the hunting and gathering lifestyle to farming did so by using his bare hands, and perhaps some sticks or stones. Tools such as knives, scythes, and wooden plows were eventually developed, and dominated agriculture for thousands of years. During all this time, almost everyone worked in agriculture, because each family could barely raise enough food for themselves with the limited technology of the day.

With the coming of the industrial revolution and the development of more complicated machines, farming methods took a great leap forward. Instead of harvesting grain by hand with a sharp blade, wheeled machines cut a continuous swath. Instead of threshing the grain by beating it with sticks, threshing machines separated the seeds from the heads and stalks.

These machines required a lot of power, which was originally supplied by horses or other domesticated animals. With the invention of steam power came the steam-powered tractor, a multipurpose energy unit that was the ground-crawling cousin to the steam locomotive. Agricultural steam engines took over the heavy pulling work of horses, and were also equipped with a pulley that could power stationary machines via the use of a long belt. The steam-powered behemoths could provide a tremendous amount of power, both because of their size and their low gear ratios. Their slow speed led at least one farmer to comment that the tractors had two speeds: "slow, and damn slow."

Gasoline, and later diesel engines became the main source of power for more modern tractors. These engines also contributed to the development of the self-propelled, combined harvester and thresher--or Combine" for short. Instead of cutting the grain stalks and transporting them to a stationary threshing machine, these combines cut, threshed, and separated the grain while moving continuously through the field.

Combines may have taken the harvesting job away from tractors, but tractors still do the majority of work on a modern farm. They are used to pull implements--machines that till the ground, plant seed, or perform a number of other tasks.

Tillage implements prepare the ground for planting by loosening the soil and killing weeds or competing plants. The most famous is the plow, the ancient implement that was upgraded in 1838 by a man named John Deere. Plows are actually used less frequently in the U.S. today, with offset disks used instead to turn over the soil and chisels used to gain the depth needed to retain moisture.

The most common type of planter is called exactly that--a planter--and spaces seeds out equally in long rows, which are usually 2 to 3 feet apart. Some crops are planted by drills, which put out much more seed in rows less than a foot apart, blanketing the field with crops.

Even after planting, other implements can be used to cultivate weeds out from between rows, or to spread fertilizer or needed pesticides. Hay balers can be used to tightly package grass or alfalfa into a storable form for the winter months.

The basic technology of agricultural machines has changed little in the last century. Though modern harvesters and planters may do a better job or be slightly tweaked from their predecessors, the $250,000 combine of today still cuts, threshes, and separates grain in essentially the same way it has always been done. However, technology is changing the way that humans operate the machines, as computer monitoring systems, GPS locators, and self-steer programs allow the most advanced tractors and implements to be more precise and less wasteful in the use of fuel, seed, or fertilizer. In the foreseeable future, some agricultural machines will be capable of driving themselves, using GPS maps and electronic sensors.

Agriculture may be one of the oldest professions, but the development and use of machinery has made the job title "farmer" a rarity. Instead of every person having to work to provide food for themselves, less than 2% of the U.S. population today works in agriculture--yet that 2% provides considerably more food than the other 98% can eat. With the continuing increases in agricultural technology, the role of a farmer will become even more important--and more rare.