Ways of increasing agricultural yield

• Yield is the amount of food produced by a certain area of land in a given time.
• Fertilisers are used to ensure that crops have enough nutrients to grow efficiently.
• Pest control

  Pesticides

  • Chemicals sprayed onto crops to kill pests
  • However they may be poisonous to humans, so must be used in small quantity
  • Can cause bioaccumulation.

  Biological control

  • Introducing a natural predator to a pest to kill them.
  • Can be less harmful to wildlife
  • No chemicals, Less pollution, No bioaccumulation.
• Hydroponics is where plants are grown without soil, but instead in nutrient solutions.

  Pros:

  • Pests and disease can be controlled more easily
  • Nutrient levels can be controlled more precisely
  • Higher yields
  • Plants can be grown anywhere
  • More space efficient (can be stacked)

  Cons:

  • Lots of fertiliser required
  • Very high initial cost
  • If a disease enters, it spreads very quickly
• Crops can be genetically modified to increase yield.
• Genetic modification is when useful genes are transferred to plants and animals, meaning they will develop useful characteristics.
• Crops can be made to be:

  • Insect resistant - prevents damage from insects, less pesticides
  • Virus resistant - prevents damage by viruses
  • Herbicide resistant - farmers can spray crop to kill weeds without damaging crop
• Selective breeding is mating the best organisms to get good offspring.
• Selective breeding

  1. Parent organisms with the best traits are selected
  2. They are bred with each other
  3. The best offspring are selected and bred
  4. Repeats, until desired traits are developed
• Advantages of selective breeding:

  • Maximum yield
  • Good health and disease resistance
  • Offspring with desired traits
• Disadvantages of selective breeding:

  • Inbreeding - Reduces the number of alleles in a population, due to animals that are closely related being bred
  • Inbreeding causes health problems such as harmful genetic disorders developing
  • If a new disease appears, the lack of variation means that if one dies, the rest are likely to.