For thousands of years, farmers have prepped their fields for seed planting using the plow. This process known as tilling turns over the upper soil layer and brings nutrients to the surface, buries the previous years’ crop residue to later break down, and mechanically kills weeds. Plows were first made from wood but then later, metallic compositions. Thomas Jefferson studied European plow design, noting their advantages and disadvantages, and coming up with improvements of his own. In 1794, Jefferson fabricated a wooden prototype which led to the manufacture of sturdier cast iron plows. In 1837, John Deere improved on the plow performance by fabricating the plow from polished steel, which was more impervious to soil sticking to it than rougher and more porous cast iron.
This basic concept of prepping the soil continues to this day in a variety of configurations and designs such as the moldboard plow, disc ripper, disc chisel, chisel plow. Up until the late 1940s and early 1950s, most every farm was organic, that is, relying on tilling to control weeds, crop rotation to control nutrient depletion, and using green manure cover crops to improve soil structure and fertility. Soon thereafter, farmers began to use chemicals such as borax and arsenic trioxide to control weed germination and growth. In 1945, the herbicide 2,4-D was introduced. When used in the right concentration, 2,4-D killed most broadleaf weeds by causing an uncontrolled growth that did not affect grasses and planted crops. More powerful herbicides followed, including Paraquat, a desiccant which robs weeds of water and causes them to die, and Dalapan, which accomplished the same by interfering with essential-to-plant-development vitamin B pantothenic acid. Though herbicides are dangerous – as little as a tablespoon of Paraquat is enough to kill a human being – their use flourished.
Read more about the Till vs. No-Till