Feeding the world involves soil and water resources, food production, social and cultural issues, food distribution and

environmental impacts1

HUMANS and FOOD

FOOD PRODUCTION Agriculture

ENVIRONMENTAL ISSUES associated with food production

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People need food for energy and nutrition (proteins, vitamins and mineral nutrients)

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Only 20 different plants and animals provide 80% of the

world's food supply

Just 3 plants comprise 65% of the world's food.

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Food Types

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Some Issues affecting Food

Culture

Efficiency

Meat production and consumption

More people can be fed with an almost all vegetarian diet

because it is more efficient

16 pounds of feed are used to produce 1 pound of beef7 pounds of feed to produce 1 pound of pork

Eggs are a very efficient animal food:3 pounds of feed to produce 1 pound of

eggsOnly two pounds of feed needed per pound of fish with aquaculture.

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67% of the US grain consumption is for livestock

only 3% used in India

In the U.S., the average person

consumes approximately 247 pounds of meat per year

For example: The industrialized countries of Europe, North America

and Japan consume 80% of the world’s meat and milk supply but are only

20% of the world’s population

Food Distribution is another issue…

As are waste, economics…8

800 million people don’t get enough to eat.

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Countries with populations that have substantial inadequate nutrition risk. Countries in white have populations with nominal risk.

But enough food is produced to feed the current population

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PovertyPoor food distributionPolitical problemsSocial/economic problemsWaste

Many social issues affect hunger:

With a growing population, will we even be able to produce enough to feed the world let alone get it to everyone?

[No democratic country with a free press has ever had a major famine (A.K. Sen, economist)] 11

Daily food supply relative to the death rate (1990)

Both too much and too little food decrease life span.12

Food Safety is another concern…

Seattle Times, 2004

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Where does our food come from?

SOILS and the OCEANS/RIVERS are the resources used to produce food.

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In the last decade, the world's fish catch has leveled off as many species have been over-fished and are now scarce.

[Harvesting wildlife could only feed a small fraction of the earth's existing population.]

Oceans and rivers are important food sources in some areas, but don’t provide most of our food.

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Where does our food come from?

The vast majority of our food comes from the soil

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is a combination of:

• rock and mineral fragments• organisms (such as plants, animals, fungi, bacteria, etc.)• organic matter• water and• air

Soils are a complex part of the ecosystem and contain layers with varying physical, chemical and biological properties.

Soil organisms

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An example of a cross section of a soil showing a soil profile that includes possible soil horizons. Actual soil profiles will vary in the number and type of horizons that are present.

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A very old tropical soil from Puerto Rico farmed for pineapple

A

B

B

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A very young floodplain soil from western Washington used to grow cabbages

A

C

C

old fire

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OA

B

C

A

A

B

Western WA forest soil

Central China soil

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To increase crop production, we must either:

• increase the amount of land used for crops or

• increase the productivity of the soil/land

The vast majority of our food comes from the soil

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Globally, approximately 4.5 billion hectares (~10 billion ac) of land are used for agriculture, with 1.5 billion ha used to

produce food

Land area harvested for grain increased by 20% from 1950 to the

1980's but has not changed since then.

For every new area of land put under cultivation, an equivalent area is

removed.At present, there is 0.23 ha (0.56 ac) of cropland per person, projected to decrease to

0.15 ha (.37 ac) 23

The best croplands are already in production 24

Most increase in crop production has come from increases in crop yield per

area of land.

Since 1950, grain yields have increased from 1 metric ton per

hectare to 2.6 metric tons per hectare (as of

1994).

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Intensive, mechanized farming using specially bred hybrids

fertilizerspesticides irrigation

have resulted in large increases in crop production per area of land.

The Green Revolution: 50 years ago the usage of high-yield crop varieties became common and has enormously increased food production

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From 1967 to 1988 irrigated land in Kansas increased by 62%

Fertilization and pesticide use have also increased

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Genetically modified crops have been used to increase productivity further.

Genetically Modified Organisms (GMO) contain DNA from another organism which alter its characteristics

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Increases in world grain production have tapered-off since 1990.

Grain production per person has decreased from a high in 1984 because of increased population growth.

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What are some of the effects of very intensive

agriculture?Ecosystems have been changed

Large areas of the world now have ecosystems that are monocultures. These are:

• less stable• less resistant to disease• and remove many nutrients when harvested

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Over 17% of the earth's surface that has soil has been degraded by human activities in the last 50

years

Soils have been lost or damaged

Water resources are being depleted

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1. Soil Erosion

2. Salinization

3. Nutrient Removal

4. Urban Development

5. Contamination / Pollution

6. Compaction

Types of soil damage include:

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Severe gully erosion results in both a loss of

productivity and siltation of streams.

Overgrazing resulting in erosion and loss of

productivity33

Wind erosion

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Effects of salinization

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Some improved agricultural practices include:

no-till cultivationcontour plowingstrip croppingstubble mulchingdrip irrigationIntegrated Pest Managementprotection of riparian zonesagroforestry

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Contour plowing and strip cropping

Minimum tillage keeping wheat stubble on fields

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Farmers produce what people want, what the area is capable of producing within given climatic conditions, and what has the most economic benefits for the farmers.

In some areas, soil degradation already limits food production.

Protecting soils for future use is Protecting soils for future use is often ignored when people are often ignored when people are

hungry or poor.hungry or poor.

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Key Points:

Only 20 plants provide the vast majority of our food, and only 3 of these provide most food.

Producing plant crops for direct human consumption is more efficient than producing meat.

Eating either too little or too much is unhealthy. Almost 1/6 of the world’s population does not get enough food to eat.

Many social issues as well as environmental issues affect availability of food.

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Key Points:The vast majority of our food comes from the soil; a complex mixture of mineral material, organic matter, water, air and organisms

Most recent increases in agricultural productivity are a result of improved plant species and use of irrigation, fertilization and pesticides

These intensive agricultural practices have degraded many soils by erosion, salinization, nutrient depletion, pollution, etc. They have also created vast areas of monocultures and depleted water resources.

Improved agricultural practices are being encouraged to slow soil degradation

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