Corn harvest: What about the parts of the plant left behind?
A common question we get in the fall during corn harvest is what happens to the rest of the plant? If farmers only need to harvest the corn cob found on each plant, where do the other plant materials go after harvest?
Let’s get into some math first…
Ontario’s corn crop produces a lot of corn that we can use to feed animals, people or make things like ethanol! In fact, in 2023, the yield or amount produced in Ontario was 170. 9 bushels per acre. A bushel of corn is a unit of measurement for the amount of corn that has been harvested and is equal to 56 pounds. So, the average amount of corn produced in Ontario per acre in 2023 was 9,570.40 pounds of corn kernels.
Why is this important? Well, with the amount of harvested corn we produce, there is a lot of corn plant needed to grow those corn kernels. In fact, for every 40 bushels of corn, 1 tonne of corn plant parts is created – on average each acre of corn will produce about 5 tones of residue.
When farmers harvest grain corn in Ontario with their combines, they are only harvesting the 1 corn cob found on the grain plant, as that one corn cob contains the grain seeds that will be used as food for animals or people. A combine will separate the seeds from a plant and spread the corn leaves, stalks, cobs, and other plant parts on the field. We call those plant parts “corn stover”. Here are a few ways corn stover can be used after harvest!
Leftover corn stover after harvest:
Fertilizer
Corn stover can be used as a fertilizer for the soil. As those corn parts decompose into the soil, they will release nutrients and minerals back into the soil to be used by the growing grain crop that is planted the following spring.
Farmers will either leave the field as is and let those the corn stover break own naturally and plant directly into that plant debris in the spring, or they can mechanically break apart the stover using tillage equipment or cutting equipment.
Incorporating tillage into farm operations can help speed the decomposition process up and will “bury” the plant residue into the soil so the nutrients are more readily available the following spring.
Another way to manage the amount of plant resides on a corn field if tilling isn’t a preferred option is to “chop” or finely cut the left-over corn parts on the surface of the soil.
Livestock feed and bedding
Another use for the corn stover involves Ontario’s farm animals! Some farmers that also have livestock on their farm, may use that stover as animal feed or animal bedding. Farmers can graze their animals on the fields or cut and gather up the stover into bales to feed in barns over the winter. Some farmers may also choose to use the corn stover as straw (like oat or wheat straw!) as animal bedding in their barns over winter.
Corn stover biofuel
Lastly, there has been research projects underway on how to use corn stover in the production of biofuels. Corn kernels can be used to make ethanol which is added to gasoline, but other research is underway for using the corn stover itself to also create a biofuel.
At the end of the day, farmers are continually looking for effect ways to manage and use their corn residues left over on their fields after harvest. Each solutions has its own benefits and drawbacks, depending on the type of operation or needs their farm has.
