The correct term that describes the practice of growing two or more crops simultaneously on the same piece of land is option 2: Mixed cropping.

Option 1: Crop rotation refers to the practice of growing different crops in a specific order or sequence on the same piece of land over a period of time in order to maintain soil fertility and prevent pests and diseases. It involves rotating crops from one season to another.

Option 2: Mixed cropping, also known as intercropping, is the simultaneous cultivation of two or more different crops in the same field. This method helps increase yield, maximizes productivity, and improves soil health by making efficient use of available resources such as sunlight, water, nutrients, and space.

Option 3: Intercropping is another term used to describe mixed cropping. It involves growing different crops together in a particular combination or pattern to optimize the use of available resources and reduce risk.

Option 4: Mixed farming refers to the practice of combining multiple agricultural activities on the same farm, such as raising livestock and growing crops. It does not specifically refer to the practice of growing multiple crops simultaneously on the same piece of land.

Therefore, the correct answer remains option 2: Mixed cropping.