Farmers and scientists use several methods to produce more food from the land available.
Hydroponics is growing plants in a solution of mineral ions instead of soil. The mineral concentrations can be controlled exactly, so plants grow quickly, and crops can be grown in places where the soil is poor. It needs equipment and energy, so it is expensive to set up.
Biological control uses a living organism, such as a predator or parasite, to reduce the numbers of a pest. It avoids spraying chemicals, but the control organism may not remove the pest completely, and it could become a pest itself.
Fertilisers add mineral ions such as nitrates to the soil, so crops grow bigger and yields rise. Pesticides kill pests that would otherwise eat or damage the crop. Too much of either can run off into streams and harm ecosystems. Gene technology can also be used to produce crops with useful characteristics.