Farming Flashcards
What are the disadvantages of insecticides, fungicides and herbicides?
- They can enter and accumulate in food chains causing a lethal dose to predators.
- They can harm other organisms living nearby which are not pests.
- Some are persistent - take a long time to break down and become harmless
What does organic farming use?
- Organic farming does not use artificial fertilisers or pesticides.
- It uses an animal manure and compost (instead of artificial fertilisers), crop rotation (to avoid build up of soil pests), nitrogen-fixing crops as part of the rotation, and varying seed planting times to get a longer crop time and avoid certain times of the cycle of insect pests.
Disadvantage and advantage of organic farming
It avoids expensive fertilisers and pesticides and their disadvantages. However, the crops are smaller and the produce more expensive. Many people leave that organic crops are healthier and tastier than other crops.
What does biological control use?
- Biological control uses living organisms to control pests. Examples of using ladybirds and certain wasp species to eat aphids, which damage plants.
- Biological control can avoid the disadvantages of artificial insecticides and as we are use living organisms, once introduced they usually do not need replacing.
- However, many attempts at biological control have caused other problems such as they introduced species eating other useful species and then showing a rapid increase in their population so they themselves become pests and then spread into other areas or countries e.g. the use of cane toads in Australia.
What happens when a new species is introduced?
Introducing a species into a habitat to kill another species can affect the food sources of other organisms in a food web, causing unexpected results.
What is intensive farming?
- Intensive farming, which makes use of artificial pesticides and fertilizers, is very efficient in producing large crop yield cheaply.
- However, intensive farming methods raise concerns about:
- animal cruelty, as animals are kept in small areas,
- and about the effects of extensive use of chemicals on soil structure and other organisms.
What does intensive farming do?
Intensive farming improve the efficiency of energy transfer in food chains involving humans by reducing or removing competing species such as animal pest and weeds. Also by keeping animals inside sheds or barns (battery farming), they use less energy to keep warm and to move, and more energy on growth (cattle) or egg production (hens).
How can plants be grown without soil?
- Plants can be grown without using soil using hydroponics. This system uses a regulated recycling flow of aerated water containing minerals and is usually done in glass houses and polytunnels.
- Hydroponics is a type of intensive farming that is especially useful in areas of barren soil or low rainfall. Tomatoes are a common crop from hydroponics.
Being a soil free system…
Hydroponics has a better control over mineral levels and disease. Many plants can be grown in a small space. As there is no anchorage for plants when using water, artificial fertilisers are used.
