Food to sustain over-increasing population. Fuel to heat homes and power vehicles. Space to build, homes and factories. Landfill site
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How and why are soil ions controlled to max crop yield
Adding fertilisers to the soil or growing in hydroponic culture. Extra mineral ions can be taken IP and used to make proteins and other compounds for growth.
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How and why is soil structure controlled to max crop yield
Ploughing fields to break up compacted soil, adding manure to improve drainage. Good aeration and drainage allow better uptake of mineral ions
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How and why is soil pH controlled to max crop yield
Adding lime to acidic soils. Soil pH can affect crop growth as an unsuitable pH reduces uptake of mineral ions
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How and why are co2, light, and heat controlled to max crop yield
Can be controlled in a glasshouse or polytunnel. May limit the rate of photosynthesis and production of the organic substances needed for growth
Slow to decompose. Build up in organism tissue (bioaccumulation). Build up and become more concentrated along food chains (biomagnification). Kill other harmless and helpful species.
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What should an ideal pesticide do
Control the pest. Be biodegradable. Be specific. Not accumulate. Safe to transport. Easy to apply.
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4 methods of biological control
Introducing a natural predator. Introducing a herbivore. Introducing a parasite. Introducing a pathogenic.
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Describe the Enhanced Greenhouse Effect (1)
Short-wavelength infrared radiation from the Sun reaches the Earth. Some is absorbed by the Earth's surface and emitted again as a longer-wavelength IR radiation
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Describe the Enhanced Greenhouse Effect (2)
The greenhouses gases absorb and then re-emit some of this long wavelength IR radiation, which would otherwise escape into space and heats up the Earth
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Effects of global warming
Polar ice cap melt and rising sea levels. Warm water flowing into cooler areas. Some areas will see increase or decrease in rainfall. Species can't adapt. Diseases spreading
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Notes on Methane
When microorganisms ferment large organic molecules. Sources are decomposition of water buried in the ground. Fermentation by MO in the stomach of cattle. Fermentation by bacteria in rice fields
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Notes on Carbon Monoxide
When fossil fuels are burned, carbon monoxide is formed. Happens when petrol and diesel are burned in vehicle engines
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Notes on Sulfur Dioxide
From FF and eruptions. Water vapour and clouds form sulfuric and nitric acids. And then rain causes acid rain.
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What can untreated sewage lead to
Aerobic bacteria breaking down the organic molecules uses up dissolved oxygen. Untreated sewage contains pathogenic bacteria
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What is the aim of sewage treatment
To remove solid and suspended organic matter and pathogenic microorganisms, so that cleaner waste can be discharged in waterways.
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Purpose of nitrates and phosphates in a fertilisers
Enable plants to make AA which are needed to make proteins. Important in cell division and development of new tissue
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What happens after eutrophication
Increase in mineral ions. Algal bloom. Death of algae. Decomposition by areobic bacteria. Bacteria uses up oxygen. Fish and other animals die
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Other cards in this set
Card 2
Front
How and why are soil ions controlled to max crop yield
Back
Adding fertilisers to the soil or growing in hydroponic culture. Extra mineral ions can be taken IP and used to make proteins and other compounds for growth.
Card 3
Front
How and why is soil structure controlled to max crop yield
Back
Card 4
Front
How and why is soil pH controlled to max crop yield
Back
Card 5
Front
How and why are co2, light, and heat controlled to max crop yield
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