20. Food supply: Humans and agriculture

20. Food supply: Humans and agriculture

demand for more food

More people means…

Agriculture

What is food mainly provided by:

Agriculture

The management of land for food production

60 people

In advanced agricultural countries a farm worker produces enough for:

Machinery, inorganic fertilizers, pesticides, monoculture, selective breeding

Factors leading to the rise in productivity of land:

Decrease in plant diversity and excessive nitrate levels in rivers

What does increased use of inorganic fertilizers lead to?

Eliminate competitors for crop species

What are pesticides used for?

Monoculture

Growing a single crop in large and specialized farms

Specialized harvesting techniques, Highly selected strains, and allow farmers to know the mineral/water requirements for that specific plant

Advantages of monoculture:

Poor wildlife foods, spread of disease, no genetic variety, damage to soil

Disadvantages of monoculture:

The minerals in the soil are drained away by many copies of the same plant

How does monoculture damage the soil?

Intensive farming

Keeping many animals in a very limited area

Temperature control, strain of animal, minimized movement, food input, hygienic conditions, veterinary care

How is intensive farming possible?

Costly heat energy must not be wasted

Why is temperature control in intensive farming important?

Animals are too uncomfortable

What happens when the temperature in intensive farming is too high?

Food intake is wasted on heat production to maintain body temperature

What happens when the temperature in intensive farming is too low?

methane

Cows and sheep release:

Methane

A very potent greenhouse gas

Antibiotics, vaccination, artificial insemination

What technology is used for veterinary care in intensive farming?

Feed conversion ratio

a ratio or rate measuring of the efficiency with which the bodies of livestock convert animal feed into the desired output

Less energy consumption 

Why does intensive farming include minimized movement?

high protein, minimal fat, growth hormones

Aspects of food input in intensive farming:

Animals must be healthy to grow quickly and meat is more saleable

Why are good hygienic conditions in intensive farming important?

waste pollution, suffering of animals, easy spread of disease, too much antibiotics lead to resistant bacteria, and expensive heating and lighting

Disadvantages of intensive farming:

Productivity

the efficiency of production of goods or services expressed by some measure

Biodiversity

the variety of life on Earth, in all its forms, from genes and bacteria to entire ecosystems