Chapter 1

Food Resources

Key Questions

 How is the world’s food produced?

 How are green revolution and traditional methods used to raise crops?

 How serious is malnutrition, and what are environmental effects of producing food?

 How do government policies affect food production?

We Depend on 3 Systems for Food Supply

 Croplands: grains, 76% world’s food  Rangelands: meat; 17% world’s food  Oceanic fisheries: 7% world’s food

Good news

: increase in production from all 3 systems since 1950 (technology)

BUT…

 To feed the world’s 9.3 billion (by 2050) people, we must produce more food than has been produced since agriculture began AND do this in en environmentally sustainable way

Bad news

: future food production will be limited by environmental degradation, pollution, lack of water, overgrazing, overfishing, etc.

What Plants and Animals Feed the World?

 Earth has 30,000 edible plant species  Only 15 plant and 8 terrestrial animals supply 90% of our calories!

 3 main grain crops (corn, wheat, rice) provide more than ½ calories people consume

Major Types of Food Production

 Industrialized agriculture: large amounts of fossil fuels, water, commercial fertilizers, pesticides to produce huge amounts of single crops; 25% of all cropland  Plantation agriculture: form of industrialized agriculture; tropical developing countries; growing cash crops on large single-crop plantations for sale in developed countries

Major Types of Food Production, cont.

 Traditional subsistence agriculture: mostly human labor; only enough crops or livestock for a farm family  Traditional intensive agriculture: farmers produce enough for their families and to sell for income

Land Labor Capital Fossil fuel energy Land Labor Capital Fossil fuel energy Industrialized agriculture in developed countries Intensive traditional agriculture in developing countries

Land Labor Capital Land Labor Capital Shifting cultivation in tropical forests in developing countries Nomadic herding in developing countries

© 2004 Brooks/Cole – Thomson Learning Ecological Services • Help maintain water flow and soil infiltration • Provide partial erosion protection • Can build soil organic matter • Store atmospheric carbon • Provide wildlife habitat for some species Croplands Economic Services • Food crops • Fiber crops • Crop genetic resources • Jobs

Producing Food by Green Revolution and Traditional Techniques

  Farmers can produce more food by 1) farming more land OR 2) getting higher yields from existing cropland (green rev.) Green Revolution: 1) developing and planting monocultures (single crops) of selectively-bred or genetic engineered crops 2) producing high yields by using a lot of fertilizer, pesticides, water 3) increasing the # of crops per year on a plot of land (

multiple cropping

)

Green Revolution, continued

 Increased crop yields in most developed countries between 1950-1970 (

first green revolution

) 

Second green revolution

: sine 1967; introduce dwarf varieties of wheat and rice, especially bred for tropical climates; 2-5x yield of traditional varieties.

 Produces more food on less land, but high inputs of fossil fuels to run machinery, produce pesticides and fertilizers, pump water

Figure 13-6 Page 282

First green revolution (developed countries) Second green revolution (developing countries) Major international agricultural research centers and seed banks

Figure 13-7 Page 282

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Cropland Irrigated farm land Rangeland Pasture Forest Barren land Wetland Urban area

Growing Techniques in Traditional Agriculture

 

1.

2.

3.

Interplanting: grow several crops on the same land; high crop diversity; reduces risk of losing entire food supply Common interplanting strategies:

Polyvarietal cultivation

: plot with several varieties of the same crop

Intercropping

: 2+ different crops grown at the same time on a plot

Agroforestry

: crops and trees are planted together

Continued…



Polyculture

: complex; many different plants maturing at different times are planted together; use less fertilizer, protection from wind and erosion, diversity of crops means less insecticides and herbicides

How Much Has Food Production Increased?

 World grain production

tripled

between 1950-1990  Population growth is outstripping food production and distribution; Africa and areas with high population growth/high poverty

Undernutrition

 To maintain good health and resist disease, people need

macronutrients

(protein, fats, carbs) and smaller amounts of

micronutrients

(vitamins and minerals)  Undernutrition: cannot meet basic energy needs; consume fewer calories than needed to maintain body weight  Children likely to suffer from mental retardation, stunted growth, and susceptibility to disease

Malnutrition

 People forced to live on a low-protein, high carb diet (grains) diet offer suffer from malnutrition  Malnutrition: deficiencies of protein and other key nutrients 

Marasmus

and

Kwashiorkor

protein and calories) (diets low in

Seriousness of Undernutrition and Malnutrition -

good news

 Average daily food intake per person in the world is expected to increase through 2030  Between 1970 and now, cases fell from 918 to 826 million (792 million in developing countries)  Projected to fall to 400 million by 2030.

Bad News

…

 1 out of 6 people in developing countries is chronically undernourished or malnourished   Each year, 10 million people (1/2 under age 5) die from undernutrition, malnutrition, susceptibility to diseases, or contaminated water Still a “silent and invisible global emergency with a massive impact on children” that can be prevented.

Poverty Malnutrition Decreased resistance to disease High death rate for children Decreased energy Decreased ability to learn Decreased ability to work Shortened life expectancy Feedback loop

Effects of Malnutrition

Micronutrient Deficiencies

 1 out of 3 people suffers from vitamin or mineral deficiency (most widespread: vitamin A, iron, iodine)  Vitamin A deficient: blindness, premature death (140 mill children in developing countries)  Golden Rice: vitamin-fortified rice expected to prevent 1-2 million premature deaths

Other Deficiencies

 Iron: fatigue, infection more likely, increases chances of death during childbirth, increases infant’s chance of dying during infancy  Iodine: stunted growth, mental retardation, goiter (enlarged thyroid)

Overnutrition

  1 out of 7 adults in developed countries Caloric intake exceeds energy use and causes excess body fat  Consequences: lower life expectancy, greater susceptibility to disease, lower quality of life   Second leading cause of preventable deaths (behind smoking) 61% U.S. population is overweight and 27% is obese.

3,700 3,500 3,300 3,100 2,900 2,700 2,500 2,300 2,100 United States Year Developing Countries

Environmental Effects of Producing Food

 Future ability to produce food will be limited by: soil erosion, desertification, salinization, waterlogging of lands, droughts, loss of wild species, global warming  40% cropland is seriously degraded

Biodiversity Loss Loss and degradation of habitat from clearing grasslands and forests Fish kills from pesticide runoff Killing of wild predators to Protect livestock Loss of genetic diversity

Erosion

Soil

Loss of fertility Salinization Waterlogging Desertification

Air Pollution Greenhouse gas emissions from fossil fuel usage Other air pollutants from fossil fuel usage Pollution from pesticide sprays Runoff and flooding from land cleared to grow crops Water Pollution from pesticides and fertilizers Sediment pollution from Erosion Fish kills from pesticide runoff Overfertilization of lakes and slow-moving rivers from fertilizer runoff, livestock wastes, and food processing wastes

Increasing World Crop Production

 Cross-breeding: developing genetically improved varieties of crops and livestock  Ex. Pear and apple: produce pear with reddish color, repeat until red dominates 

Cross-breeding is

: slow (15 years or more to produce desired trait), can combine only traits from species who are closely-related, successful for 5-10 years until pests reduce their yield

Pear Crop Desired trait (color) Cross breeding Apple Offspring Best results Cross breeding New offspring Desired result

Genetic engineering

 Gene revolutions: using genetic engineering to develop new genetically improved strains of crops  Genetic engineering: insertions of alien gene into a commercially valuable plant to give it new (beneficial) genetic traits  Genetically-modified organisms (GMOs): organisms that receive the “new” genes

Genetic Engineering, continued

 Compared to traditional crossbreeding, it takes half as much time; costs less, and allows insertion of genes from

any

other organism

Pros and Cons?

  No strong evidence that genetically engineered crops cause environmental harm Doesn’t mean that they don’t cause environmental harm  Plans to bioengineer pathogens to destroy other countries’ crops (kill coca plants in Columbia)

Projected

Figure 13-17

Need less fertilizer

Page 292

Need less water More resistant to insects, plant disease, frost, and drought Faster growth Can grow in slightly salty soils Less spoilage Better flavor Less use of con ventional pesticides Projected Disadvantages Irreversible and unpredictable effects Harmful toxins in food from possible mutations New allergens in food Lower nutrition Increased evolution of pesticide-resistant insects and plant diseases Creation of herbicide resistant weeds Harm beneficial insects Lower genetic diversity

Expansion of the Green Revolution

 Can we provide food to all 9.3 billion people by new advances in gene-splicing and spreading the use of green revolution techniques throughout the world?

 What should we DO?

Will People Try New Foods?

 Some recommend eating more variety of plants (ex. Winged bean from SE Asia)  Black ant larvae (tacos in Mexico)  Giant waterbugs (veggie dip in Thailand)  Emperor caterpillars (South Africa)  Cockroaches (Kalahari desert)  Lightly toasted butterflies (Bali)  Fried ants (Columbia street food)

In use Cultivated Grazed Tropical forest Arid land 6% 8% 11% 10% 14% 51% Forests, arid lands Ice, snow, deserts mountains Not usable © 2004 Brooks/Cole – Thomson Learning

Is Cultivating More Land the Answer?

 Theoretically, we could double the amount of cropland by clearing tropical forests and irrigating arid lands  BUT, this would: 1) destroy valuable forest resources 2) reduce earth’s biodiversity 3) affect water quality 4) cause serious environmental problems  Cultivation of these lands is unlikely to be sustainable (parasites, nutrient-poor areas, etc.)

Producing More Meat

 Rangeland: 40% of earth and 29% total US land; too dry, steep, or unfertile to grow crops; vegetation for grazing animals   Pastures: managed grasslands or meadows planted with domesticated grasses Livestock can be raised 1) on open ranges (rainfall is low by regular) and 2) by nomadic herding (herders must move livestock to find ample grass because of very low and irregular rainfall)

Ecology of Rangelands

   Grasses have complex root systems that help anchor plants Extract water from underground to help with drought Store nutrients so plants can grow again after drought or fire  Metabolic reserve: grass is eaten and its lower half remains; if lower half is also eaten plant can weaken and die (overgrazing)

Good

- Metabolic Reserve Intact

Ungrazed Grazed Recovery Metabolic reserve Metabolic reserve intact Metabolic reserve

Bad

– Metabolic Reserve Destroyed

Ungrazed Overgrazed Death Metabolic reserve Most of metabolic reserve eaten Death

Increasing World Crop Production

 Crossbreeding and artificial selection  Genetic engineering (gene splicing)  Genetically modified organisms (GMOs)  Continued Green Revolution techniques  Introducing new foods  Working more land

Meat Production

   Between 1950-2000, meat production increased 5x!

80% of world’s cattle, sheep, goats are raised on rangeland by open grazing or nomadic herding Ruminants: animals with complex digestive systems that convert grass to beef, milk, etc.

 Feedlots: where animals are fattened for slaughter by feeding on grain or fishmeal  Industrial approach

Meat Production Problems

 Concentrates pollution problems (odors, waters with animal waste, water contamination from nitrates in waste)  Increases pressure on grain supply and fish supply  Increases use of fossil fuels  Increases spread of disease (mad cow, hoof-and-mouth)

Overgrazing

 1.

2.

3.

4.

Too many animals graze for too long and exceed carrying capacity of grazing area Lowers net primary productivity of vegetation Reduces grass cover and exposes soil to erosion Compacts soil (cannot retain as much water) Desertification

Overgrazing

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Undergrazing

 Absence of grazing for long periods of time (5+ years)  More likely in arid areas with erratic rainfall  Mostly areas where livestock are raised by nomadic herding

Managing Rangelands Sustainably

  1.

2.

3.

Goal: to maximize livestock productivity without overgrazing or undergrazing Methods include: Controlling number, types, and distribution of grazing animals Deferred grazing Rangeland restoration

Rangeland Restoration

(Arizona) Overgrazed

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Restored

Catching and Raising More Fish

 World’s Fisheries: concentrations of particular aquatic species suitable for commercial harvesting in a given ocean or body of water  Commercial fishing industry uses: satellite positioning equipment, sonar, huge nets, spotter planes, factory ships (freeze and process fish on the spot)

Demersal

Hake

Pelagic

(surface dwelling) Anchovy

Sardine

Herring

Haddock Mackerel Crustaceans Shellfish Mollusks

Oyster Clam

Krill

Shrimp Lobster

Octopus Cod Tuna Crab Squid

trawl bag Fish farming in cage trawl lines Spotter airplane sonar Purse-seine fishing Long line fishing fish school Drift-net fishing Fish caught by gills buoy lines with hooks

Overfishing and Habitat Degradation Affect Fish Harvests

 Fish are renewable resources as long as there are enough left to breed (sustainable yield)  Sustainable yield is difficult because: 1. hard to estimate mobile populations 2. shifts from year to year because of climate change, pollution, etc.

Bycatch

   Nontarget fish that are caught along with targeted fish ¼ of annual catch is bycatch (depletes biodiversity and doesn’t supply food) 75% world’s 200 commercially valuable fish are overfished  14 major commercial fish in the US are so depleted that it would take 20 years for stocks to recover!!

  1.

2.

Is Aquaculture the Answer?

Aquaculture: fish and shellfish are raised for food (33% of world’s commercial harvest)

2 types

: Fish farming: raise fish in controlled environment, and harvest when they reach desired size Fish ranching: using spawning patterns, hold fish in captivity, then release and harvest when they return to spawn

Advantages Highly efficient High yield in small volume of water Increased yields through crossbreeding and genetic engineering Can reduce overharvesting of conventional fisheries Little use of fuel High profits Disadvantages Large inputs of land, feed, and water needed Lots of waste Destroys mangroves Increased grain production needed to feed some species Fish can be killed by pesticide runoff from cropland Dense populations vulnerable to Disease Contamination of tanks

Something to Think About

  Agriculture in a financially risky business Depends on weather, crop prices, diseases, pests, etc.

 Should we reward ranchers who protect the soil, conserve water, protect land, and farm sustainably?

 Key to reducing hunger and malnutrition = slowing population growth, reducing poverty, and sustainable agriculture