Agriculture danks

Food ResourcesFood Resources

See Miller Chapter 12See Miller Chapter 12

Issues and Impacts of AgricultureENVS 1 Oct. 14, 2002

Main TopicsMain Topics

Methods of producing foodMethods of producing food

Increasing food productionIncreasing food production

Environmental effects of food productionEnvironmental effects of food production

Issues of sustainabilityIssues of sustainability

Sources of food worldwideSources of food worldwide

Of 30,000 edible plants, only 15 spp. supply 90% of our food

Of 30,000 edible plants, only 15 spp. supply 90% of our food

Primary plants:wheat, corn, and rice

Provide < ½ calories people consume

Primary plants:wheat, corn, and rice

Provide < ½ calories people consume

Primary animals:cattle, pigs, and chicken 2ndary: Eggs, milk & cheese

Primary animals:cattle, pigs, and chicken 2ndary: Eggs, milk & cheese

Major Types of AgricultureMajor Types of Agriculture

Traditional subsistenceShifting cultivationNomadic herding

Traditional subsistenceShifting cultivationNomadic herding

Traditional intensiveTraditional intensive

PlantationPlantation

IndustrializedIndustrialized

Fig. 12.3a, p. 264

Industrialized agriculturein developed

countries

Intensive traditional agriculture

in developing countries

Land

Labor

Capital

Fossil fuelenergy

Land

Labor

Capital

Fossil fuel energy

Fig. 12.3b, p. 264

Shifting cultivation in tropical

forests in developing

countries

Nomadic herding indeveloping countries

Land

Labor

Capital

Land

Labor

Capital

Industrialized agricultureIndustrialized agriculture

Shifting cultivationShifting cultivation

Plantation agriculturePlantation agriculture

Nomadic herdingNomadic herding

Intensive traditional agricultureIntensive traditional agriculture

No agricultureNo agriculture

World Food ProductionWorld Food Production

Fig. 12.2, p. 263

Fig. 12.8a, p. 268

2,000

1,500

1,000

500

0

Gra

in p

rod

uct

ion

(mill

ion

s o

f to

ns)

1950 1960 1970 1980 1990 2000 2010

Total World Grain Production

Fig. 12.8b, p. 268

400

350

300

250

150

Per

cap

ita

gra

in p

rod

uct

ion

(kilo

gra

ms

per

per

son

)

1950 1960 1970 1980 1990 2000 2010

Per Capita World Grain Production

200

Green RevolutionsGreen Revolutions

First green revolution(developed countries)First green revolution(developed countries)

Second green revolution(developing countries)

Second green revolution(developing countries)

Major International agricultural research centers and seed banksMajor International agricultural research centers and seed banks Fig. 12.4, p. 265

Producing Food by Green-Revolution TechniquesProducing Food by Green-Revolution Techniques

High-input monocultureHigh-input monoculture

Selectively bred or genetically-engineered crops

Selectively bred or genetically-engineered crops

High inputs of fertilizerHigh inputs of fertilizer

Extensive use of pesticidesExtensive use of pesticides

High inputs of waterHigh inputs of water

Increased intensity and frequency of cropping

Increased intensity and frequency of cropping

Results of Green Revolution: MixedResults of Green Revolution: Mixed• Higher yields per acre when inputs

available• Lower yields when inputs unavailable• Increased dependence on cash economy• Increased dependence on fossil fuel• Increased imports of inputs

• Income disparity??• Migration to cities??

Unintended consequences: Killer BeesUnintended consequences: Killer Bees

Mild-mannered, low honey producing Italian beeX

Aggressive, high honey producing African bee?

Hope for a mild-mannered, high producing bee

Instead, got an aggressive, low producing bee

Worse yet – it escaped, and is interbreeding with other bees making them aggressive & low producing too!

Environmental Effects of Food ProductionEnvironmental Effects of Food Production

Biodiversity lossBiodiversity loss

Soil degradationSoil degradation

Air pollutionAir pollution

Water pollutionWater pollution

Human healthHuman health