When I started ag college almost 60 years ago, the extensive use of chemicals on the farm was just becoming the norm. Grandpa had used a little commercial fertilizer on fields far away from the barn. Horses were used to draw manure out to the fields and most of it was spread not too far from the barns. He used a little DDT on the potatoes to kill potato bugs and fly spray on the milk cows to give them a little comfort when they were out on pasture, but because some chemicals were invented to kill the enemy in wars, he was reluctant to use them extensively.
My first year in college, the crops professor told the class that it cost more to haul and spread manure on the fields than it would to replace it with chemical fertilizer. When I came home to farm, I soon realized that there was something in that manure that chemical fertilizer could not replace. We bought our first little three-point hitch sprayer that mounted on the big 35-horsepower tractor. For a few years the only chemical that we used was 2,4-D or MCPA which were both in the same family as Agent Orange. It only cost 50 cents per acre for the chemicals to spray weeds in corn or grain. That sure was cheaper and easier than cultivating corn with the one-row horse cultivator.
Dad had bought a little tractor-mounted cultivator for the little grey “Fergie” that cultivated either two rows of corn planted in 38- or 40-inch rows or three rows planted in 28- or 30-inch rows. We then used 2,4-D to spray on corn to kill pigweed and lambsquarters but cultivated between the rows to kill grass. We later replaced that little two-row cultivator with a six-row. Once we bought a 12-row planter, we replaced the six-row cultivator with a 12-row. Whether we cultivated one row with the horse or 12 rows with a tractor, it was always the calmest, and most precise driver who cultivated corn. It was sure faster with the 12-row cultivator than using the horse, but if the driver got off the row for just a second, he tore out 12-rows of corn.
Many thought it was a waste of time cultivating corn, but when you came home before the field was finished and returned a day or two later to finish, you could easily see a four or five inch difference in the height of the corn that was cultivated compared to the corn that had not been cultivated.
Cultivating lets some air into the soil that not only kills the grass that is competition for nutrients but also improves the release of nutrients in the soil. Whether you were tilling soil before planting or cultivating after the corn came up, Dad said, “if you don’t get your face dusty, then you are just transplanting weeds and you would be better just resting under a tree.”
A cultivator brings the grass roots to the surface of the ground and the sunlight kills the roots exposed to the sunlight. It was for the same reason that Dad said a cultivator is better for killing grass than a disc. A disc cuts the grass roots and buries them so those grass roots will grow twice as much, but a cultivator brings grass roots to the surface so the direct sunlight can kill them.
Then some new herbicides were released like Atrazine and Lasso that did a pretty good job of killing perennial and annual grasses. For a few years those chemicals worked pretty good. Then Lasso was taken off the Canadian market because of concerns that it may cause cancer. Soon after, scientists noticed that Atrazine was showing up in creeks, rivers, and even well water. Scientists also noticed some frogs exposed to atrazine had both female and male sex organs and could not reproduce. Soon after that, restrictions were placed on the sale and use of Atrazine.
The most valuable herbicide released was Roundup, which contained glyphosate as the main ingredient. When first released, it was touted as the herbicide that killed everything except a GMO variety. It is a chelator, which binds some minor elements rendering them unavailable to plant growth. That is why some weeds will no longer grow when sprayed with glyphosate. As time passed on, more and more weeds became immune to glyphosate and questions began showing up about some health problems that it may have caused like stomach ulcers, other digestive disorders, an increased risk of miscarriages and even some types of cancer.
Glyphosate is also registered as a bactericide which kills many types of bacteria. While some beneficial bacteria that line the gut, or are found by the millions on a teaspoon of topsoil, may be killed, some other very difficult bacteria like E-coli, salmonella, and clostridium (C-difficile) have shown a high resistance to glyphosate.
In the first week of this month, the Trump administration urged the U.S. Supreme Court to limit the tens of thousands of lawsuits filed against the manufacturer of Roundup, many of which argue a connection between cancer and exposure to the pesticide.
Some farms are now in their fifth generation of farming in ways that are dependent on chemicals to control weeds and have developed different farming methods because of them. Many European and Asian farmers have farmed for the same length of time growing excellent crops without those chemicals now in question. Maybe it’s time to have a chat with Grandpa or some of those farmers from “the old country” to find out how they did it or still do it?
I’m just an old farmer with no degree in chemical science, or even agriculture, and most of the information above is from personal experience or articles written by scientists.
