B6 - ways of increasing agricultural yields

what is yield?

what is yield?

the amount of food produced by a certain area at a given time

what are pesticides?

a form of chemical pest control which are sprayed onto crops to kill the pests that damage them

PESTICIDES

there are several types of pesticides:

• insecticides kill insects

• herbicides kill unwanted plants

• fungicides destroy unwanted fungi

some pesticides also harm other wildlife that aren’t pests such as ladybirds and bees. This can cause a shortage of food along the food chain.

also, some pesticides stick around and can be passed along food chains - this can kill organisms further up.

what is biological control

an alternative to using pesticides. It involves using other organisms to reduce the number of pests. This is done by encouraging wild organisms or adding new ones

BIOLOGICAL CONTROL

the helpful organisms could be predators (ladybirds eat aphids), parasites (some flies lay their eggs on slugs, eventually killing them) or disease causing (bacteria that affect caterpillars)

biological control can have a longer-lasting effect on than spraying pesticides, and be less harmful to wildlife. But introducing new organisms can cause problems e.g. cane toads were introduced to Australia to eat beetles, but now they’re a major pest themselves because they poison the native species

biological control can be considered a safer alternative to pesticides. This is because no chemicals are used, so there’s less pollution, risk to people eating the food and no passing of chemicals along food chains