Resources and environment, Year 11: increasing and sustaining supply (Food option)

Hydroponics

提示The first part of the word is Greek for the liquid involved.

为什么Hydroponic crops are usually grown indoors or under glass, where light, temperature and nutrients are controlled. Yields are high, less water is used and crops can be grown all year, even in cities. The equipment and energy are expensive, so it suits high-value crops such as salad leaves and tomatoes.

They are sprayed with a fine mist of nutrient solution

提示Think of a perfume bottle.

为什么Because the roots hang in air they take in plenty of oxygen, and very little water is used. Like hydroponics, aeroponics needs costly equipment and a reliable power supply.

Raise yields sustainably: crops bred to resist drought and pests, with soil and water conserved

提示It tries to avoid the damage the first one did to land and rivers.

为什么The first green revolution fed millions but left some regions with polluted water, salty soils and falling water tables. The new one uses biotechnology, including genetically modified crops, together with methods such as water harvesting, crop rotation and soil conservation.

Appropriate technology (also called intermediate technology)

提示Two words; the first means 'suitable'.

为什么These methods cost little and do not depend on imported fuel or spare parts, so they keep working. AQA lists appropriate technology among the ways of increasing food supply.

roots

提示The part of the plant below the ground.

为什么Flooding or spraying a field loses much of the water to evaporation and run-off. Drip irrigation puts water into the root zone, so far less is wasted. Irrigation of any kind lets farmers grow crops in dry seasons and dry places, which raises the food supply.

Salt (salinisation)

提示Crops cannot tolerate it, and the sea is full of it.

为什么All river and ground water carries dissolved salts. In a hot climate the water evaporates from the soil and leaves the salts behind, and after some years crops fail. This is one disadvantage to weigh in a large-scale agricultural development, against its gains in food and jobs.

Permaculture

提示The name blends 'permanent' with 'agriculture'.

为什么A permaculture plot might grow fruit trees above vegetables, keep hens to eat pests and collect rainwater for dry spells. Waste from one part feeds another, so little fertiliser or fuel has to be bought in. It aims to keep the soil healthy for the long term, not to get the highest possible yield.

The food is grown close to the people who eat it, so it travels only a short distance

提示Compare a rooftop to a field on another continent.

为什么Urban farming uses spare land, rooftops and even walls inside towns and cities. As well as cutting transport, it gives low-income households fresh food and can provide work. It cannot feed a whole city, but it makes the food supply more secure.

Fish are caught no faster than the stock can breed and replace them

提示Compare what is taken out with what is born.

为什么If more fish are caught than are replaced, the stock shrinks year by year until the fishery collapses. Sustainable fisheries set catch limits (quotas), use nets that let young fish escape and protect breeding areas. The same idea applies to meat: animals raised without destroying forest or exhausting the land.

Poor storage and transport, so food rots or is eaten by pests

提示Think of grain kept in an open sack through a hot, wet season.

为什么The FAO estimates that about 13% of the world's food is lost between harvest and the shop. Sealed grain stores, cool storage and better roads cut these losses. In higher income countries (HICs) more food is thrown away later, by shops and households: that is called food waste.

Local people must be able to pay for it and run it themselves once the charity has gone

提示Ask who mends the pump and buys the seed in year four.

为什么A sustainable scheme lasts. It uses appropriate technology, trains local people, makes or saves money for them and does not damage the soil or water it depends on. When you write about your own example, show each of these: social, economic and environmental.