Book 9, Question 98
Why Rotate Crops on Farms?
Farmers rotate crops, which means they grow different plants in a field each year! Different plants take and give back different nutrients, and they face different pests. Rotation keeps the soil healthier and the crops stronger, year after year.
More fun facts
- Many grain farms use a two year rotation, planting corn one year and soybeans the next, then repeating.
- Satellite pictures show many fields switching between corn and soybeans, with some winter wheat mixed in.
- In one study, farms with a wider mix of crops needed only a fraction of the usual fertilizers and weed killers.
- Researchers found that more crop rotation can cut fossil fuel use while still growing big harvests and making money.
- Some farmers grow alfalfa and other 'cover crops' that are left on the field instead of being harvested.
- Leftover stalks from different crops trap snow and keep soil moist in different ways.
Sources: National Geographic, NASA Science
Questions kids ask
Why not plant the same crop every year?
Different crops use and add different nutrients, so switching helps keep soil healthy.