To feed a growing global population, we need to produce more food. In biology, we look at several modern agricultural methods used to increase food production. A key term for this is 'yield', which means the amount of useful product obtained from a crop or animal.

One way to increase yield is by using agricultural machinery, like tractors. Another is adding chemical fertilisers to the soil. These provide essential mineral ions, such as nitrates, which plants need for healthy growth.