A plow is one of the most critical pieces of agricultural machinery. It's used to till the soil and prepare the field for crop planting. Plows have an extensive history; they are depicted in Egyptian carvings and mentioned in the Bible. The modern plow owes a debt to American inventor John Deere, who revolutionized the machine -- and farming -- by fashioning it from steel.

Early Plows

Before the late 1700s, American farmers used wooden plows pulled by oxen to till their fields. Since the wood wore out quickly, blacksmiths plated thin iron strips onto the moldboards -- the curved metal plates that turn over the soil. Wooden plows were not mass produced because their parts weren't standardized. David Peacock patented a plow with a cast-iron moldboard and a wrought-iron, steel-edged share -- the cutting part -- in 1807. In 1814, Jethro Wood patented a plow with replaceable parts.

John Deere

John Deere was a journeyman blacksmith who moved to Illinois in 1836 and was quick to notice the problems his customers had with their plows. The soil of the Midwest was wetter and heavier than that of the east, and farmers were having to repeatedly interrupt their plowing to scrape the soil from the clogged moldboards of their plows. Deere's first plow was created using a broken saw blade shaped over a log. Eventually, he created and sold plows with a polished iron moldboard and steel share. He also discovered through experimentation that steel quality impacted the performance.

Steel Plow Advantages

Steel plows succeeded in thick sod and rich, clay-like soil where iron and wood plows had failed. The steel plows shed the soil as the plow cut through it, rather than collecting it on the moldboard. The steel plow is also burnished by the grinding action of the soil, keeping it sharper and cleaner. Deere's plow also only required half the draft power of earlier plows.

Impact

Deere's "singing plow," so called for the high-pitched whine it made as it cut through soil, was so in demand that by 1857, the newly formed John Deere company produced 10,000 plows, many of which were on covered wagons headed West. The next major improvement in agricultural tillage machinery wasn't until the 1870s, when riding plows came into existence.