B4h: Farming Flashcards Preview

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Flashcards in B4h: Farming Deck (14):

Disadvantages of pesticides (3)

they are artificial chemicals which can enter and build up in food chain (bioaccumulation) causing a lethal dose to predators

some pesticides are persistent and can directly affect human health

chemicals could be toxic for organisms which are not pests and may damage environment


How can plants be grown without soil(2)

Using hydroponics
-roots are exposed to a regulated recycling flow of solution containing the minerals they need


What is hydroponic usually used in(2)

Growing tomatoes in glass houses

Growing plants in areas with barren soil


Advantages of hydroponics (4)

plants can be grown in areas w/ poor soil, because no soil is needed

better control of the type and concentration of minerals needed by the plant

diseases can be controlled

several rows of plant can be stacked above one another; better use of space


Disadvantages of hydroponics (2)

no support for plant as roots are not anchored in soil - frame/tray needed

no soil to hold and store minerals - fertilisers need to be added constantly as dissolved minerals


Advantages of intensive farming(3)

Improves efficiency of energy transfer and increases energy available for growth(or egg production)
-reduces energy transfer to to pests and competing plants (weeds)
-reduces energy lost as heat via respiration since animals cannot move around as much and are kept warmer


Disadvantages of intensive farming(2)

ethical dilemas - less humane as animals have no freedom to move around

rapid spread of disease as they are always so close together


Organic methods to improve plant growth (4)

animal manure or compost instead of artificial fertilisers


crop rotation to avoid build up of soil pests, include nitrogen fixing crops as part of the rotation

variation of seed planting times to avoid certain times of the life cycle of insect pests


Advantages of organic farming methods (3)

uses -chemicals, -risk of toxic chemicals remaining on food

-chance of polluting river w/ fertiliser; -pesticides, food chains not disrupted, wildlife unharmed

ethical treatment of animals; no battery farming


Disadvantages of organic farming methods (3)

requires +space than intensive farming; more land has to be farmland rather than for wildlife

+labour-intensive so more expensive

-food produced


What is organic farming

farming methods that do not use intensive techniques, artificial chemicals/fertilisers or pesticides


What is biological control

using a natural predator to control/kill pests, instead of using chemical pesticides


Advantages of biological control (3)

no need for artificial chemicals to be used
-no chemicals to escape into environment and damage or kill other animals/no bioaccumulation

repeat treatments not needed if predators survive for a long period(unlike when using chemicals)


Disadvantages of biological control (5)

predator may not eat pest

predator may eat other useful species

predator may increase in number and become out of control

predator may not stay in required location

adding/removing organisms from any food web may have an impact on numbers of other organisms in that web; other pests may rise in number