I still remember when our Grade 10 agriculture teacher took the class to a nearby farm to watch a farmer plow a field of loamy soil. It was on a cold afternoon in October of 1964. We had just learned about topsoil and subsoil. The farmer was planting furrows about seven or eight inches deep, and below that we could see the yellowish subsoil. You do not want to plow deeper and bring up subsoil. Subsoil has no nutrients and it won’t grow crops. I have plowed up thousands of acres these past 51 years and I try not to bring up subsoil. When a bit does come up in places, it is mixed in with the good soil.
Some soils are only a few inches thick – on mountains, some deserts and arctic regions. Other soils can be more than six feet deep. Soil along the Nile River in Egypt is probably the deepest in the world at 92 feet. Very deep black soil is found in the Ukraine and in a few other places in the world. Topsoil is usually the top five to eight inches; below that, the subsoil may go down many feet.
The Old Testament book of Ecclesiastes says there is a time for everything, a season for every activity under heaven. There is a time to plant and a time to harvest. There’s no mention of plowing, which is understandable. It wasn’t until steel plows were invented in the early 1800s, and perfected by John Deere, that the rural landscape was changed by plowed fields.
Farmers plow for several reasons: to create a favourable seedbed for the spring-planted crop (plowed land dries quicker); to add fertility to the soil by burying crop residues, sod, green cover crops and cattle manure, which will break down and become humus; to remove or help prevent the growth of weeds; to destroy insect pests and disease organisms; and to promote the circulation of air and water through the soil.
In other words, plowing allows you to integrate cover crops, compost, other organic material and mineral amendments into the soil. Without tillage, cover crops and residue form a thin layer of highly organic material on the surface of the soil instead of being distributed throughout the soil profile.
I have a European-made five-furrow rollover plow (five furrows or blades up and five down). You plow in the same furrow, which means all the furrows are turned the same way, leaving no ridges or dead furrows in the field. I can plow five to seven acres an hour in long fields.
Plows are equipped with coulters – round steel discs mounted immediately in front of the plow bottom – which revolve and cut through plant debris, such as the soybeans trash on the surface, making it easier for the plow to cover up stubble, trash and sod. I feel that farmers who follow the zero-tillage practice tend to rely too heavily on chemical herbicides.
Most of the population doesn’t know the difference between a plow and tillage or seeding equipment. Numerous times I’m asked in the spring if I’m finished plowing. I explain that plowing is done in the fall and that farmers usually don’t plow in the spring. Spring plowing can dry out the soil, and you don’t want that in a dry summer. Spring field work consists of disking, cultivating, no-till seeding or conventional seeding. None of those machines look like a plow.
Then they’ll say, “Oh, well whatever you do on the land. I have no idea what all those machines are for.”
Plowing is a wonderful autumn job. It’s a wonderful sight to see the ground turned over in neat, straight furrows with no variation or grass showing in the furrows. Furrows should be smooth and consistent. Uneven plowing looks bad – almost as bad as referring to it by the wrong term. It does have one benefit, however: rough plowed fields dry quicker in the spring, but it’s hard on the operator as he bounces along in the tractor when he disks or cultivates.