L14 and 15 Gary Foster - Cereals and Food security Flashcards
How much of the Earth’s total land is arable?
Total: 14.7 billion hectares of land
Arable: 3.1 billion
Where is the most arable land?
Countries with most arable land are also most developed, and areas of massive population growth.
Poor soil areas have the most malnourished and underweight children.
What family are grasses?
Poaceae - 4th largest angiosperm family.
837 genera, 10.5-11000 species.
Provides 80% global food
What are the most important crops?
Rice - Poaceae Wheat - Poaceae Maize - poaceae Potatoes Barley - poaceae Tomatoes Soybeans Oranges Sorghum - poaceae Banana
Describe the physiology of grasses/
Monocots
parallel veined leaves
Perrenial or annual herbs
Flowers are on spikelets, contain 1+ florets
leaves are alternate, open sheath with ligule and blade
Why are grasses successful?
Very wide geographical range, wider than any other plant family. Tropical to arctic.
Diverse adaptations.
Can tolerate most grazing as apical meristem is below ground so it is not bitten off and new growth can be initiated.
which part has the most energy and nutrients?
Seed!
Endosperm’s capacity to synthesise large quantities of carbohydrates makes cereals so economically important.
Which is the most efficient cereal for carbohydrates, and 2 others?
Rice - 38.1 x10^6 Kj/Ha
Maize - 33.1
Wheat - 27.7
Why is the growing population and land loss a problem when it comes to rice farming?
1 ha of rice can feed ~ 4700 people for 1 day, as people need ~8000 Kj per day.
In the near future, this 1 ha will need to feed 10-20,000 people.
Which Amino acids are cereals very high in?
Glutamate and proline
What are the major arable crops in the UK?
Wheat and also oilseed rape - used to feed livestock.
Also lots of grain imported from Australia to UK.
Where are the major wheat producing countries?
USA, Russia, Australia, China, E. Europe. 1/3 US grain exported.
Lowest: African countries, Indonesia
Why is it an issue importing loads of grain>?
Rich countries are buying land from poorer ones to use the resources to feed people. Problems if el nino event or war or pathogen outbreak in australia - would cause them to use their excesses and then food shortage.
What would happen if the UK stopped getting imports?
We would have enough reserves to feed the population for 5 days.
how much do wheat and barley take up of arable land in the UK?
Wheat - 63%
Barley - 31%
In what way is the UK countryside not ‘pure’ anymore?
What takes up 63% of UK arable land, and it isn’t even a native plant - originally from middle east, adapted to ~UK.
So it is ridiculous for people to complain that GM plants would make the countryside ‘impure’.
How has the yeild of crops been pushed?
Using new varieties, fertilisers and pesticides. Now we have pretty much reached the limit.
1 tonne of wheat used to make 1695 loaves of bread. A 2-3 fold increase has let us supply the economy with 678 billion extra loaves per annum.
Why has the global rate of yield increase actually decreased?
years 1961-1990 compared to 1990-2007.
Yeild is actually higher but increasing more slowly as we have almost reached the limits.
Study by Alston, Parday and Beddow, 2010
China is crazy because..
they have a rapidly increasing population, but as they get richer, have turned rice paddies into cattle fields.
Why would Norman Borlaug win a nobel peace prize?
Breeding new varieties of wheat. Without these new varieties, could lead to world hunger and wars break out.
What mistake are developing countries making?
As they get richer, meat production is increasing. Doesn’t make sense as reduces he land and food availability for people.
eg 40% of cereals grown in US arefed to livestock, whereas only 14% on average in Africa.
What is the agricultural revolution?
Switch from hunter-gatherer to herder-farmer. 12-8000 years ago.
what are 5 agricultural advances
- introduction of new crops
- Mechanisation - this increased CO2 output
- New and improved varieties
- inorganic fertilisers
- persticides and fungicides (many now banned)
What are 7 further crop enhancements?
- High crop yeild
- High nutritional quality
- N fixation - so less fertiliser use
- Drought resistance
- Pest resistance
- Plant architecture
- Toxic/unwanted compounds