Agriculture

space availability seasonality demand weather conditions

temperature light water soil pH carbon dioxide soil fertility soil salinity

• optimal growing season temperature and length of season • frost free period or frost resistant crops • drought and water availability • shelter for warmth e.g: greenhouses trap heat in gas burners in orchards to keep trees warm transparent covers over trees barns for animals

• photosynthesis rate • can provide artificial light Eg’s of light affecting: • longer days -> longer farming days • more light -> more reproductive rate • longer day -> more milk production • shorter day -> faster chicken grows (battery hens in semi darkness) • longer day -> more egg production

• transpiration -> temp regulation • turgidity (flaccid) • reliability of rains • pH of water e.g acid rain • water logged soil can drown crops • water can create fungal growth • irrigation systems e.g sprinklers • water shortage -> cell damage -> death

• most plants between pH 5 and pH 7 • increase pH by adding crushed lime (calcium carbonate) • decrease pH by spreading powdered sulfur

• limiting factor in rate of photosynthesis • can pump CO2 into greenhouses by burning carbon based fuel e.g gas

• nutrients affect soil growth • fertilisers add nutrients • too many fertilisers can lead to eutrophication common primary macronuntrients: nitrogen -> manufactures proteins phosphorus -> root growth potassium -> ion and seed development organic fertiliser - manure inorganic fertiliser - chemicals advantage of inorganic - know exactly how many nutrients dis - toxic to animals eg worms, can be washed away (eutrophication)

• how salty soil is (do not want) • osmotic dehydration of roots • reduce by irrigating more but greatly increases water consumption

no soil but growing plants in a controlled manor. Means crops can be grown all day so grow more quickly and can be more efficient with space

fungus bacteria pests

rot plants cant use rotted plants

mad cow disease, over 300 people killed

• pests –> pesticides • insects will eat and damage crops e.g termites eat trees, tree dies e.g rabbits, rats, mice, birds, weed, snails and slugs (molluscs), nematode worms • scarecrows can keep crows away deal with pests by: crop rotation - changing crops annually/ seasonally companion crops - growing 2 crops together to deter pests pest attraction - planting desirable crops to deter pests flowering plants - attracts bees, increases pollination predator habitats - attract predators to kill pests sterile male - release sterile insects to kill off fertile insects pheromone traps - lures insects into trap and kills them genetic modification - modify crop dna to resist pests pesticides - chemical but shows results much quicker* perks of pesticides: toxicity specific - target specific pests not all animals persistent insoluble - could enter water system contact - kills when comes into contact with pest systematic - absorbed into crop so when bitten it kills plant antibiotic - kills bacterial pests in plants, as well as animal pests