Answer: Controlled fires
Step-by-step explanation:
Sometimes there will be unwanted plants in an area as well as undergrowth from forests that limits the growing of crops. There are very few ways to control these plants and burning is the most effective.
Some people will react by cutting down the trees in the forests next to the field so that the undergrowth can stop while others would simple set the field on fire which can lead to forest fires.
Controlled fires can help stop both things. If the farmers can carefully plan the fires such that it can be contained to an area, they can get rid of both the undergrowth and the unwanted plants without the fires spreading and becoming wildfires and without the need to cut down trees in the forests thereby limiting both deforestation and wildfires.