Agricultural solutions for a growing populationSpec 4.13B
The human population is growing, so more food is needed. Two agricultural solutions are the use of fertilisers and biological control.
Fertilisers
Fertilisers add mineral ions, such as nitrates, to the soil. Plants need these to grow well, so crop yields are higher.
- Advantage: increased growth and yield, so more food is produced from the same land.
- Disadvantage: fertilisers can be washed off fields into rivers and lakes, which can harm wildlife and pollute water.
- Disadvantage: they cost money, so the farmer's costs go up.
Biological control
Biological control is the use of living organisms to control pests. For example, ladybirds can be released to eat aphids.
- Advantage: no chemical residues are left on the food, and harmful chemical pesticides are not needed.
- Advantage: the control organism usually targets only the pest, and can keep working over a long time.
- Disadvantage: it is slower than pesticides and may not completely remove the pest.
- Disadvantage: the control organism might itself become a pest, or might eat other organisms, harming the ecosystem.