Food and Soil ResourcesFood and Soil Resources

G. Tyler Miller’sLiving in the Environment

14th Edition

Chapter 14

G. Tyler Miller’sLiving in the Environment

14th Edition

Chapter 14

Two Worlds

Soil, a limited resource we depend upon, but take for granted

Chapter 14: Key ConceptsChapter 14: Key Concepts

Methods of producing food Methods of producing food

Increasing food production Increasing food production

Soil degradation Soil degradation

Increasing sustainability Increasing sustainability

Aldo LeopoldAldo Leopold

There are two spiritual dangers in not owning a farm. One is the danger of supposing that breakfast comes from the grocery store, and the other that heat from the furnace.

Section 1: How Is Food Produced?Section 1: How Is Food Produced?

• What systems provide us with food?

• What plants and animals feed the world?

• What are the major types of food production?

How Food Is ProducedHow Food Is Produced

Historically:

• Croplands (77%)

• Rangeland (16%)

• Ocean Fisheries (7%)

Since 1950 there has been a staggering increase in all production.

Huge technology increase

How Food Is ProducedHow Food Is ProducedTechnology Changes:• Farm machinery• Fishing equipment• Fertilizers• Pesticides• Irrigation• GE Foods• Feedlots• Fish farms

Each improvement brings new challenges

How Food Is ProducedHow Food Is Produced

Can we meet the challenge of feeding 9 billion people by 2050?

• W/O Degradation of environment

• And reduce poverty (1 of 5 do not produce enough food)

How Food Is ProducedHow Food Is Produced• 30,000 possible plant species

people can eat

• Since ag. rev. 10,000 consumed

• Today: 14 plants, 8 terrestrial animals provide 90% calories

• 3 (wheat, rice and corn) provide ½ world’s calories – all annuals (potatoes huge also)

• Dramatic reduction in biodiversity of agriculture

• Most cannot afford meat

How Is Food Produced?How Is Food Produced?

Sources of foodSources of food

3 Primary plants:wheat, corn, and rice

3 Primary plants:wheat, corn, and rice

4 Primary animals:fish, beef, pork, and chicken

4 Primary animals:fish, beef, pork, and chicken

Major Types of AgricultureMajor Types of Agriculture

Industrialized agricultureIndustrialized agriculture

Traditional subsistence agricultureTraditional subsistence agriculture

PlantationPlantation

Traditional intensive agricultureTraditional intensive agriculture

Major Types of AgricultureMajor Types of Agriculture

Industrial Agriculture:

• Fossil Fuel Energy

• Heavy Water Use

• Single Crops (monoculture)

• Commercial fertilizers

• ¼ of all cropland

• Mostly in developed countries

Industrial agriculture in California

Major Types of AgricultureMajor Types of AgriculturePlantation Agriculture:

• Form of industrial agriculture in tropical developing countries

• Cash crops: banana, coffee, sugar cane, cocoa

• Monoculture for sale in developed countries

• Increasing large livestock

Coffee Plantation

Major Types of AgricultureMajor Types of Agriculture

Traditional Subsistence Agriculture:

• Human labor and draft animals producing food form family survival

• Nomadic herding

• 42% of world’s people uses traditional agriculture

Major Types of AgricultureMajor Types of Agriculture

Traditional Intensive Agriculture:

• Increasing human and animal labor, fertilizers, water to get higher yields

• Enough food for family and to sell locally

• Agriculture is world’s leading industry

World Food ProductionWorld Food Production

Fig. 14-2 p. 275

Hunterdon County, New Jersey

Section 2: Producing Food by Green-Revolution TechniquesSection 2: Producing Food by Green-Revolution Techniques

High-input monoculture High-input monoculture

Selectively bred or genetically-engineered crops

Selectively bred or genetically-engineered crops

High inputs of fertilizer High inputs of fertilizer

Extensive use of pesticides Extensive use of pesticides

High inputs of water High inputs of water

Multiple cropping Multiple cropping

Green Revolution in AgricultureGreen Revolution in Agriculture

Since the 1950s farmers having been getting huge increases in crop production per unit of land.

First Step: develop and plant monocultures of GM high-yield crops like corn, rice and wheat

Cavendish Banana

Green Revolution in AgricultureGreen Revolution in AgricultureSecond Step: Use large inputs

of fertilizers, pesticides and water.

Third Step: Increase number of crops grown per year on a plot of land (more crop less land)

These techniques produce huge increases in crops BUT need lots of water, fossil fuels, machinery, pesticides, fertilizers

* Uses 8% of world’s oil *

Green Revolution in U.S.Green Revolution in U.S.

Agribusiness: loss of the family farm to corporate farming…Superfarms

• U.S. Ag. More total sales than auto, steel and housing combined

• 18% of Gross National Income (1/5 of all U.S. private sector jobs)

• 0.3% of world’s farmers produce 17% of world’s grain (1/2 of world’s corn and soybeans)

• Huge increase in efficiency

Green Revolution in U.S.Green Revolution in U.S.Developed Countries: People spend

about 40% of income on food

Developing Countries: 70%

Industrial Ag. Needs cheap fossil fuels…putting food on table accounts for 17% of energy used in U.S.

Energy used to grow, store, process, package, transport, refrigerate, cook

10 units of energy for 1 unit of food energy in your stomach

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. 14-4 p. 277

Producing Food by Traditional TechniquesProducing Food by Traditional Techniques

Interplanting Interplanting

Polyvarietal cultivationPolyvarietal cultivation

IntercroppingIntercropping

Agroforestry (alley cropping)Agroforestry (alley cropping)

PolyculturePolyculture

Look up terms on page 278

Showing where energy is used in food production in U.S. Food travels avg. of 1,500 miles from farm to fork in U.S.

New Jersey Peach Farm: What are the advantages and disadvantages of eating locally grown food?

Section 3: Soil ErosionSection 3: Soil Erosion

• What causes soil erosion?

• How serious of a problem is it?

• Good news and bad news from the U.S.

• What is desertification?

• How do salts degrade the soil?

Causes of Soil ErosionCauses of Soil Erosion

Wind

Water #1

People

Wind

Water #1

People

Why care about soil erosion?

Impacts of Soil ErosionImpacts of Soil Erosion• Loss of soil fertility

• Sediment runoff causes problems in surface water (pollution, clog ditches, boat channels, reservoirs)

• #1 source of U.S. water pollution

• Renewable only on LONG timeframes (200-1,000yrs. for 1 inch)

Soil ErosionSoil Erosion

On Ag. land in U.S. today, soil is eroding 16 times faster than it is created

Areas of serious concern

Areas of some concern

Stable or nonvegetative areas

Global Soil ErosionGlobal Soil Erosion

Fig. 14-7 p. 280

Soil Erosion in the USSoil Erosion in the US

Dust Bowl – 1930s: Fig. 14-5 p. 281

Reductions in erosion since 1987

1985 Food Security Act

Dust Bowl – 1930s: Fig. 14-5 p. 281

Reductions in erosion since 1987

1985 Food Security Act

Huge Erosion Problems During “Dust Bowl” era

Causes of DesertificationCauses of Desertification

OvergrazingDeforestationErosionSalinizationSoil CompactionNatural Climate Change

OvergrazingDeforestationErosionSalinizationSoil CompactionNatural Climate Change

Refer to Fig. 14-10 p. 283

World DesertificationWorld Desertification

Fig. 14-9 p. 282

Desertification: causes and consequences.

•Occurring on 1/3 of world’s land

SalinizationSalinization1. Irrigation water

contains small amounts of dissolved salts

2. Evaporation and transpiration leave salts behind

3. Salt builds up on soil

Reducing and Cleaning Up SalinizationReducing and Cleaning Up Salinization

Reduce irrigationSwitch to salt-tolerant cropsFlush soilsNot growing crops for 2-5 yearsInstall underground drainage

Reduce irrigationSwitch to salt-tolerant cropsFlush soilsNot growing crops for 2-5 yearsInstall underground drainage

Refer to Fig. 14-12 p. 283

Soil Degradation on Irrigated LandSoil Degradation on Irrigated Land

Salinization Salinization

Waterlogging1. Precipitation and

irrigation water percolate downward

2. Water table rises3. Bad for roots

Waterlogging1. Precipitation and

irrigation water percolate downward

2. Water table rises3. Bad for roots

EvaporationTranspiration

Evaporation

Waterlogging

Less permeableclay layer

Fig. 14-11 p. 283Fig. 14-11 p. 283

Section 4: Soil ConservationSection 4: Soil Conservation

• What is soil conservation and how does it work?

• What are some methods for reducing soil erosion?

• Inorganic versus organic fertilizers

Soil ConservationSoil Conservation

Involves many ways of reducing soil erosion and restoring fertility to soil.

Conventional TillageConventional TillageFarmers plow the land and

then break up and smoothes soil to make a planting surface

• Leaves soil vulnerable to erosion

• Midwest tillage often down in fall (winter bare)

Conservation TillageConservation TillageDisturbing the soil as little

as possible while planting crop

• Not tilling over winter• Planting without

disturbing soil• Special equipment

“inject” soil with seed, fertilizer etc.

• In 2003 45% of U.S. farms

Solutions: Soil ConservationSolutions: Soil Conservation

Conventional-tillageConventional-tillageConservation tillage Conservation tillage Terracing Terracing

WindbreaksWindbreaksLand ClassificationLand Classification

Refer to Fig. 14-14 p. 285Refer to Fig. 14-14 p. 285

Contour farming Contour farming Strip and alley cropping Strip and alley cropping

Terracing

Used on steep slopes

Reduces erosion and water loss

Contour planting

Planting crops in rows across the slope

Strip Cropping

Alternating crops from row crops and crops that completely cover surface

Cover Crops: can be planted right after harvest to hold onto soil during winter

Alley Cropping: several cops planted together in rows (alleys) Increases shade (less water) Provide windbreaks

Windbreaks

Soil RestorationSoil Restoration

Organic fertilizerOrganic fertilizer

Commercial inorganic fertilizerCommercial inorganic fertilizer

Animal manureAnimal manure

CompostCompost

Crop rotationCrop rotation

Organic FertilizerOrganic Fertilizer

Has decreased in the U.S. due in part because most farmers no longer raise livestock and it costs too much to transport

• Poop Factory and Phillies Soil

• Inorganic fertilizers have taken off

Inorganic FertilizersInorganic FertilizersNitrogen, Phosphorous,

Potassium• Grown in usage worldwide• Credited with increasing

crop yields (1/4 of world crops)

• W/o could only feed 2-3 billion people

• Many problems associated (see next slide)

The amount of energy needed to produce a single hamburger is enough to power a small car 20 miles