Agriculture can threaten biodiversity in many ways. Three examples are:
- Monoculture.
- Overuse of herbicides and pesticides.
- Overuse of fertilisers.
Monoculture
- Monoculture is an agricultural practise where only one species is produced.
- Monoculture allows us to produce large amounts of food at a lower cost.
- The entire crop can be treated with the same type of fertiliser and pesticide, and can be harvested at the same time.
Monoculture threatens biodiversity because:
- Other plants are prevented from growing, therefore reducing the biodiversity of plants.
- The animals that relied on those other plants for food or shelter can no longer live in that environment. This reduces the biodiversity of animals.
Overuse of Herbicides and Pesticides
- Herbicides and pesticides kill organisms that damage and reduce food crops. This reduces competition between crops and insects.
- However herbicides and pesticides can also kill useful organisms such as bees.
- They can stay in the environment for a long time and can be passed to other organisms through the food chain.
Overuse of Fertilisers
- Fertilisers are substances that are applied to add nutrients to soil. They can be natural, like slurry, or they can be artificial.
- Using fertilisers increases the growth of plants and therefore the amount of food that can be produced from the land.
- If fertilisers wash into streams or lakes they can cause huge growth of algae. The algae uses up the oxygen in the water, causing fish and other animals and plants to die.
Conserving Biodiversity in Modern Agriculture
- Providing economic incentives for farmers who use measures that help to conserve biodiversity on their farms.
- Organic farming does not use any chemical herbicides or pesticides.
- Crop rotation which is when different species of crops are grown in a field each year.
- Organisations such as the Rainforest Alliance offer support and certification to farmers who practise food production in a sustainable way.