3.1A Food security and Sustainable Food production

Question 1

what is food supply?

Answer 1

the provision and distribution of food to a consumer

Question 2

what is food security?

Answer 2

food security is the ability of human population to access food in sufficient quantity and of sufficient quality

Question 3

Explain Human population growth?

Answer 3

humans must be able to provide enough food to meet their needs
the world is facing a potential food security crisis because the human population has been rapidly increasing having reached 7 billion in 2012 and predicted to reach over 9 billion by 2050.

Question 4

How does this increase in population impact on food security?

Answer 4

the increase of global human population has raised the overall requirement for food and increased the difficulty in ensuring food security for all

Question 5

What are natural factors that affect food production?

Answer 5

drought
pests
flooding
disease
desertification
resistance to insecticides

Question 6

What must food production be?

Answer 6

its important that it must be sustainable and does not degrade the natural resources that are vital for agriculture

Question 7

Explain the environmental impacts?
Global warming
Pollution
Deforestation
Soil Erosion
Reducing Soil Fertility

Answer 7

• increased food production causes an increase in greenhouse gases that contribute to global warming
• Pesticides and fertilisers can pollute land or nearby rivers
• forests may be cleared to make way for agricultural land, contributing to greenhouse effect and also leading to habitat loss reducing species diversity
• Intensive farming practices can cause loss of fertile top soil by erosion
• Harvesting crops means nutrients are not naturally recycled and so fertility of soil is reduced

Question 8

DONT FORGET!

Answer 8

photosynthesis is the process by which green plants (autotrophs) produce food using light energy
the light energy is trapped by the pigment chlorophyll in chloroplasts

Question 9

What does the production of all foods depend on?

Answer 9

photosynthesis

Question 10

What must animals including humans eat and why?

Answer 10

must eat plants(and other animals) to obtain energy

Question 11

Where do most human foods come from?

Answer 11

a small number of plant crops including cereals, potatoes, root vegetables and legumes

Question 12

What is primary productivity?

Answer 12

primary productivity of a growing crop is the rate at which light energy is converted into carbohydrate during photosynthesis within a period of time
calculated in kj/m2/year
Global ecosystems have different rates of primary productivity
An increase in productivity results in an increase in biomass or total crop yield

Question 13

What is the economic yield?

Answer 13

economic yield is the biomass from the crop that can be sold (e.g. rice grains)

Question 14

What is the harvest index?

Answer 14

calculated by dividing dry mass of economic yield by dry mass of biological yield
the higher the harvest index value, the higher the economic value of the crop

Question 15

TOPTIP!

Answer 15

productivity is affected by:
light intensity
abiotic factors such as temperature
soil type
efficiency of leaves at capturing light (shape, size, angle, area)
crop density
availability of nutrients

Question 16

Factors limiting plant growth - light intensity?

Answer 16

light intensity limits the rate of photosynthesis. As light intensity increases, the rate of photosynthesis increases and so does plant growth

Question 17

Factors limiting plant growth - carbon dioxide concentration?

Answer 17

carbon dioxide concentration also limits the rate of photosynthesis. An increase in CO2 concentration increases the rate of photosynthesis and so increases plant growth.

Question 18

Factors limiting plant growth - temperature?

Answer 18

At low temperature, plant growth is limited. This is because the reactions of photosynthesis are controlled by enzymes with an optimum temp of about 35 degrees celsius. As temperature increases up to 35 degrees celsius, plant growth increases. Above the optimum temp plant growth decreases as enzymes become denatured.

Question 19

Factors limiting plant growth - availability of nutrients?

Answer 19

Green plants require several chemical elements for healthy growth. If there are not present in the soil, growth will be affected.

Question 20

Factors limiting plant growth - pests and disease?

Answer 20

Plants can be damaged by invertebrate pests or their growth can be inhibited if there is competition with other plants for light, water or soil nutrients

Question 21

What does intensive farming result in?

Answer 21

an increase in food production but may have undesirable side effects, for example herbicides and pesticides reduce biodiversity.

Question 22

Explain live stock animals?

Answer 22

since energy is lost between trophic levels keeping animal livestock can result in less food production per unit area of land in agriculture.
Land planted with cereal crop such as wheat can be more productive in terms of overall food than the same area of posture kept for cattle.