B6.2a Flashcards
What is food security?
The ability it human populations to access AFFORDABLE food if sufficient quality and quantity.
This can be an issue for individuals and entire countries
What are the main factors affecting food security and why?
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HOW DO PATHOGENS AND CONFLICT CAUSE LESS FOOD
4) pests and pathogens evolving
- these can cause widespread loss of crops / livestock due to them, leading to FAMINES !!!this can only be avoided if international travel stopped…)
5) conflicts cause problems in underdevloping
- blocks trade routes and LAND FOR GROWING
Similybwhat are the main factors affecting food security
1) population, diet, climate, pests, conflict, cost of agricultural
How to increase food production then!
Photo, fertilisers and crop rotation, pesticides (3 thpes but biological control), herbicides, gm crops, hydroponics
1) maximise photosynthesis, so more glucose is converted to carbs and biomass for food
- involves using industrial greenhouses to maximise co2, light, temp and water (limiting factors)
2) Use fertilisers
- plants use certain elements when growing from ground and fertilisers help replace it (however not sustainable )
- crop rotation
- allows soil to recover and re gain minerals it lost (as different plants use different minerals), also prevents BUILD UP of PESTS)
4) pesticides : insecticides for insect and fungicides for disease causing fungi (not good for environment) , increase crop production
- therefore Biological control instead
6) herbicide to remove competition
7) finally better crops that are pests resistant or better at yield.
(Perhaps him modified ones…)
8) hydroponic system so less space used
What is being sustainable in terms of food production?
Using techniques such that today’s populations needs are met without harming the environment for future generations to use for themselves,
so if we use non renewable resources to feed us now, it won’t help them man later on…
Why are fertilisers not sustainable?
Instead what?
It’s negative impact on environment as excess fertiliser can run off into fields and end up in ponds, rivers, lakes etc which can cause eutrophication
Instead use manure or dung instead of artificial.
What is biological control and why is used instead of just pesticides?
By killing pests you increase the production obviously …
However what can be the problem sometime?
Typical pests like aphids are dealt by using a pesticide, however, these may KILL THE OTHERS!! other organisms (other wildlife not pests) and thus cause a shortage of food in a food chain, and passing through food chain kill organisms further up (by eating pests who were killed by pesticide).
1) HOWEVER, crop pests have natural predators, such as ladybird for aphid, and farmers can exploit this by BREEDING them to kill the pests. A DISEASE BACTERIA similarly (for caterpillars eg) can be bred too.
- this safer than. Pesticides, no chemicals used, less pollution, risk to other organisms and passing of chemicals along food chain.
- (however sometimes this predator can become the pest like frog in Australia).
What are hydroponics and how useful?
How does it thus increase yield but what are considerations
- Plants can instead of soil be grown in water with nutrients dissolved into them.
+ commercial industrial level can stack rows of plants Like this on top of each other, so more plants grown in less space and QUICKLY too
+ good for climates in harsher areas , like barren soil or little rainfall
+ pests disease controlled more, and. Trients too, so it is easier to regulate them for maximise growth potential (put as much or little as want)= higher yields
- a lot of fertiliser, too much money to set up and IF DISEASE COMES IN SOMEHOW, ROPES
How can fish be farmed sustainably?
1) what do farmers currently do,
2) what can they do
3) what about fish farming?
Currently farmers use sonar, so now more fish have been found than before. Also use large negs, with SMALL holes, meaning small fish can’t escape. Although this means lot fish for us, means populations are reduced and can’t regenerate , so won’t be able to feed us in future, so not sustainable . As a result
1) larger holes used in nets, so only mature big fish can be caught, while small fish can grow and breed, giving us future food
2) international fishing quotas put in, so fish can survive and reproduce and not die out
3) bans on fishing in breeding seasons alike
4) fish can also be farmed, THEY are REARED in large cages which they can be bred too. This means fish protected from predators, easier to catch and can recover if were in low numbers.
But disease spread quickly , risky…
Hat is intensive farming ?
How is it done in livestock?
- what disadvantage is there
In plants ?
Labour?
The idea that the MAXIMUM HIELD is produced fromthe MINIMUM amount of land…
1) livestock are kept as close together and restrict movement as possible, meaning more food given is transferred Into biomass, as they now warmer and not use as much energy in movement (indoors= warmer, so less energy used to make body heat).
- protein put in fertiliser too.
- Antibiotics as disease can spread easily in such closed areas but (not good as promotes antibiotic resistance…)
- (again fish farmed or intensively farmed in cages)
2) fertilisers and pesticides in plants and everything else
3) minimising labour inputs by using machinery…
What is organic farming
Using more natural methods of producing crops and livestock, such as avoiding use of chemicals. Yields however are more smaller so thus more expansive too( premium applied )
- for example, more space given to roam, less energy is taken via growth so more expensive now…
What is selective breeding ?
1) the process of breeding organisms to get desired characteristics m such as plants for better food.
Example they will choose cows with most milk, biggest etc. This way offspring more likely to have these characteristics too
In plants, high resistance to disease, high yield etc
How does selective breeding work?
1) select parents with desired characteristic (high levels of it atleast)
2) breed them
3) select the best offspring, breed them again
4) repeat
Eventually after many generations, all the animals or plants will have high levels of desired characteristic .
You can also d this to combine two good characteristics into one… like pea plant high yield and fall but not strong, or short one strong but no yield. Combine and you get tall strong high yield and redotsat
What are disadvantages of selective breeding ?
1) reduces gene pool available
- reduces the number of different alleles in a population, as farmer breeds from the bets of the best which are closely related, inbreeding
- this can cause health problems as they are more likely to get genetic diseases (such as pugs getting breathing problems due to this)
- also if a disease appears, not enough variation means that an organism isn’t likely to have the required resistance, and by natural selection, due. All the stock are closely related so everyone dies too Lmao
What characteristics are diesarble in plants and animals ?
Plants = high yield, attractive flowers, smell, strength Animals= speed, temperament, looks (pugs), disease resistance, mass , milk etc
