Corn stover facts for kids
Corn stover is what's left of a corn plant after the corn kernels have been harvested. It includes the leaves, stalks, and cobs. Think of it like the "straw" from corn plants. It's a very common leftover material in places where a lot of corn is grown.
About half of what a corn plant produces is stover. Sometimes, other weeds and grasses might get mixed in with the stover in the field. Both field corn (the kind used for animal feed or fuel) and sweet corn (the kind we eat) produce similar corn stover.
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What is Corn Stover Used For?
Corn stover is a useful material that farmers can use in many ways. It's often used on the farm itself, but it can also be turned into other products.
Feeding Farm Animals
One of the main uses for corn stover is as food for farm animals, especially cattle. This animal food is called fodder.
- Grazing: After the corn kernels are picked, farmers can let their cattle walk into the fields and eat the stover directly. This is a cheap way to feed the animals. Any corn kernels that were missed during harvest also become extra food for the cattle. Farmers try to let the cattle graze soon after harvest because the stover loses its food value over time. A field of corn stover can feed about one cow per acre for one to two months.
- Silage: Sometimes, the whole corn plant (kernels and stover together) is chopped up and stored in a special way called silage. This makes the plant material last longer and become a valuable food source for animals like dairy cows, especially during winter. The chopped pieces are crushed between rollers during harvest.
- Collected Fodder: Corn stover can also be cut and gathered by special machines called corn binders or balers. These machines can roll the stover into large round bales, similar to hay bales. These bales can then be stored and fed to animals later.
Animal Bedding and Soil Helper
Besides feeding animals, corn stover can be used in other ways on a farm.
- Animal Bedding: Farmers can collect corn stover and use it as bedding for their livestock in barns. It helps keep the animals clean and comfortable by soaking up animal waste.
- Helping the Soil: After being used as bedding, the stover, now mixed with animal waste, can be spread on fields. This adds important nutrients and organic matter back into the soil, which helps new crops grow better.
- Directly in the Field: If the stover isn't used for feed or bedding, it can be left directly in the field after harvest. This is good for the soil because it adds organic material back into it. It's like a natural fertilizer. This also helps keep the soil healthy and prevents it from drying out or eroding.
When stover is left in the field, it needs to be managed carefully. The tiny living things in the soil that break down the stover need nitrogen. If there isn't enough nitrogen, they might take it from the next crop, which could make the new plants grow poorly. Farmers can add more nitrogen to the soil, either naturally (like with animal waste) or with special fertilizers.
Making Energy (Bioenergy)
Corn stover can also be used to create energy or other useful products.
- Burning for Electricity: Corn stover can be burned in special furnaces. The heat from burning creates steam, which can then be used to generate electricity.
- Cellulosic Ethanol: Scientists are also working on turning corn stover into ethanol, a type of fuel. This is called "cellulosic ethanol" because it comes from the plant's tough fibers (cellulose), not the corn kernels themselves. It's a way to make fuel from parts of the plant that aren't used for food.
- Renewable Natural Gas: A company called Verbio bought a plant in Iowa that used to make ethanol from corn stover. Now, this plant turns corn stover into renewable natural gas. This gas can be used to power vehicles. As a bonus, this process also creates a soil-enriching material called humus, which is similar to compost.
Corn stover is a good choice for making bioenergy because there's so much of it available, especially near places where corn is already grown for other uses.
What is Corn Stover Made Of?
Corn stover is made up of different parts. Here's a look at its main components:
| Component | Percentage (dry weight) |
|---|---|
| Cellulose (plant fiber) | 37.4% |
| Xylan (another plant fiber) | 21.1% |
| Lignin (makes plants woody) | 18.0% |
| Ash (minerals left after burning) | 5.2% |
| GCV (energy content) | 18.6 MJ/kg |
| Protein | 3.1% |
| Acetate | 2.9% |
| Arabinan | 2.9% |
| Galactan | 2.0% |
| Mannan | 1.6% |
The HHV (Higher Heating Value) of corn stover is about 19 MJ/kg when it's dry and ash-free. This number tells us how much energy can be released when it's burned.
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