Final answer:
The term for planting multiple crops together, like corn, that benefits each other's growth is known as intercropping, an example being the 'Three Sisters' method.
Step-by-step explanation:
When cultivating corn in a spot with 10-12 plants, the term that describes planting multiple crops together to enhance each other's growth is known as intercropping. This form of agriculture is beneficial as it can improve soil fertility, diversify crops, and naturally break the cycle of weeds, pests, and diseases. An example of this is the traditional combination referred to as the "Three Sisters", where corn, beans, and squash are planted together. The corn provides a climbing structure for beans, while beans contribute nitrogen to the soil, and squash acts as a living mulch to suppress weeds and conserve soil moisture.