850 million people in developing countries do not have enough to eat• Political obstacles• Inefficiencies in distribution• Every 5 seconds a child starves to death• Since 1970 we have reduced world hunger from 26% to

13%

Food security is the guarantee of an adequate and reliable food supply available to all people at all times

Undernutrition = people receive fewer calories than their minimum requirements • Due to economics, politics, conflict, and inefficiencies in

distribution

Malnutrition- people receive fewer vitamins, minerals, proteins and/or nutrients than minimum requirements

Most undernourished live in developing nations• But 50 million Americans are “food insecure”

Food security = guarantee of an adequate, safe, nutritious, and reliable food supply

Undernutrition has decreased since the 1960s

The human population is expected to reach 9 billion by 2050• This will mean 2 billion more people to feed

Food production has exceeded population growth over the last 50 years

We produce food through technology • Fossil fuels, irrigation, fertilizer, pesticides, cultivating

more land, genetic engineering

Today, soils are in decline and most arable land is already farmed

Agriculture = practice of raising crops and livestock for human use and consumption

Cropland = land used to raise plants for human use

Rangeland or pasture = land used for grazing livestock

Land devoted to agriculture covers 38% of Earth’s land

Different cultures independently invented agriculture Evidence for the earliest plant and animal domestication is

from the “Fertile Crescent” of the Middle East Agriculture rose independently in at least China, Africa, and

the Americas Raising crops was a positive feedback cycle

• Harvesting the crops required people to be sedentary

• Being sedentary encouraged the planting of more crops and production of more food

• More crops allowed larger populations

• Larger populations required planting more crops

Traditional Agriculture- performed by humans and animal muscle power with simple tools and machinesUse of polycultures• Subsistence agriculture- families produce enough food to

feed themselves• Intensive- produce excess food to sell in market Stops short of using fossil fuels

Industrialized Agriculture- large scale mechanization and fossil fuel combustion Use of monocultures• Replaces horses and oxen• Cultivate, harvest, transport and process crops at higher

yields

Three systems produce most of our food• Croplands: 77%

• Rangelands, pastures, and feedlots: 16%

• Aquaculture: 7%

Importance of wheat, rice, and corn

Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food travels an average 2,400 kilometers from farm to plate.

Figure 13-7

Monocultures• More efficient = increased output• Reduces biodiversity• Narrowed human diet 90% of the food consumed comes from just 15 crop species

and 8 livestock species

I.A. occupies 25% of the world’s cropland Intensive cultivation creates problems with the

integrity of the soilBad soil = no crops = decrease in population

About 80% of the world’s food supply is produced by industrialized agriculture.• Uses large amounts of fossil fuel energy, water, commercial

fertilizers, and pesticides to produce monocultures.

• Greenhouses are increasingly being used.

• Plantations are being used in tropics for cash crops such as coffee, sugarcane, bananas.

1950’s the Green Revolution introduced to the developing world to boost agricultural production:• New technology, crop varieties and farming practices

Created from the desire for greater quantity and quality of food for the growing population

Increased yields and decreased starvation Developing countries were able to double

,triple or quadruple yields

Depended on heavy use of:• Synthetic fertilizers and chemical pesticides

• Irrigation

• Fossil fuel-powered machinery

From 1900 to 2000, cultivated area increased 33% while energy inputs increased 80 times

Positive effects on the environment• Prevented some deforestation and land conversion

• Preserved biodiversity and ecosystems

Lack of water, high costs for small farmers, and physical limits to increasing crop yields hinder expansion of the green revolution.

Since 1978 the amount of irrigated land per person has declined due to:• Depletion of underground water supplies.

• Inefficient irrigation methods.

• Salt build-up.

• Cost of irrigating crops.

Modern agriculture has a greater harmful environmental impact than any human activity.

Loss of a variety of genetically different crop and livestock strains might limit raw material needed for future green and gene revolutions.• In the U.S., 97% of the food plant varieties available in the

1940 no longer exist in large quantities.

Benefit to the environment:• Used already cultivated land Prevented some deforestation and habitat conversion

Preserved biodiversity and natural ecosystems

Harm to the environment:• Intensive application of water, fossil fuels, inorganic

fertilizers and synthetic pesticides Increases pollution, erosion, salinization and desertification

Feeding the world’s rising human population requires changing our diet or increasing agricultural production • But land suitable for farming is running out

Mismanaged agriculture turns grasslands into deserts, removes forests, diminishes biodiversity and encourages the growth of non-native species• It also pollutes soil, air, and water with chemicals

• Fertile soil is blown and washed away We must improve the efficiency of food

production while we decrease our impact on natural systems

Over the past 50 years, soil degradation has reduced potential rates of global grain production by 13% on cropland and 4% on rangeland

Most degradation results from cropland agriculture, overgrazing by livestock and deforestation

Increased vulnerability through:• Over cultivating fields through poor planning or

excessive tilling

• Overgrazing rangelands with more livestock than land can support

• Clearing forests on steep slopes or with larger clear-cuts

Soil degradation is especially severe in arid environments

Desertification = a form of land degradation with more than a 10% loss of productivity

Caused primarily by wind and water erosion, but also by:• Deforestation, soil compaction, and overgrazing

• Drought, salinization, water depletion

• Climate change

Arid and semiarid lands (drylands) are most prone to desertification• Cover about 40% of the Earth’s surface

Prior to industrial agriculture in the Great Plains, the native short-grass prairie held the soil in place

In late 1800 and early 1900, farmers and ranchers:• Grew wheat, grazed cattle

• Used unsuitable land and removed native grasses

Dust Bowl = massive dust storms from erosion of millions of tons of topsoil in the 1930s• Drought worsened the human impacts

• Dust storms traveled up to 2000 km (1250 miles)

• Thousands of farmers left their land

No-till farming has many benefits It increases organic matter and soil biota

• Reduces erosion and improves soil quality

• Uses less labor, saves time, causes less wear on machinery

Prevents carbon from entering the atmosphere (carbon storage)—may help mitigate climate change• Reduces fossil fuel use due to less use of the tractors

• Adds organic matter to soils that is kept from the atmosphere

40% of U.S. farmland uses conservation tillage

• Erosion rates in the United States declined from 9.1 tons/ha (3.7 tons/acre) in 1982 to 5.9 tons/ha (2.4 tons/acre) in 2003

In Brazil, Argentina, and Paraguay, over half of all cropland is now under no-till cultivation

• Crop yields have increased while costs have dropped

May require increased use of herbicides and fertilizers To minimize problems:

• Use green manure (dead plants as fertilizer)

• Rotate fields with cover crops

Grazing is sustainable as long as:• Do not exceed the ranges carrying capacity

• Do not consume grasses faster than they can grow back/be replaces

Overgrazing occurs when many animals eat too much plant cover• Impeding regrowth

• Prevents replace of biomass

• Creates positive feedback loop/cycle

Positive feedback loop- instead of stabilizing a system (negative feedback loop), they drive it further towards another extreme• When livestock remove too much plant cover, more

soil is exposed and made vulnerable to erosion. Erosion makes it difficult for vegetation to regrow perpetuating the lack of cover and give rise to more erosion

• Degraded soils = great home for invasive species to outcompete native plants

Overgrazing can compact soil• Harder for water to infiltrate

• Harder for soils to aerate

• Harder for plant roots to expand

• Harder for plants to conduct cellular respiration

Traditional agriculture relied on organic fertilizers Industrial agriculture uses more inorganic

fertilizers Inorganic fertilizers are more susceptible to

leaching and runoff• Runoff into surface waters far from the point of application,

causing “dead zones” in water bodies

• Nitrates volatilize (evaporate) into the air and contaminate groundwater

• Nitrates and phosphates in drinking water can cause cancer and blue-baby syndrome in infants

Nutrients can be added to drip irrigation and are delivered directly to the plants

No-till planting allows the application of fertilizers with the seeds rather than spreading it across the soil

Monitoring of soil nutrients can prevent unneeded applications

Organic fertilizers provide needed nutrients as well as improving the soil by• Improving soil structure

• Increasing nutrient-holding capacity

• Increasing water-retaining capacity

Fig. 13-18, p. 285

Biodiversity Loss Soil Water Air Pollution Human Health Loss and degradation of grasslands, forests, and wetlands

Erosion Water waste Greenhouse gas emissions from fossil fuel use

Nitrates in drinking water

Loss of fertility Aquifer depletion

Pesticide residues in drinking water, food, and air

Salinization Increased runoff and flooding from cleared land Other air pollutants

from fossil fuel use

Fish kills from pesticide runoff

Waterlogging

Sediment pollution from erosion Greenhouse gas

emissions of nitrous oxide from use of inorganic fertilizers

Contamination of drinking and swimming water with disease organisms from livestock wastes

Desertification

Killing wild predators to protect livestock

Fish kills from pesticide runoff

Surface and groundwater pollution from pesticides and fertilizers Belching of the

greenhouse gas methane by cattle

Loss of genetic diversity of wild crop strains replaced by monoculture strains

Bacterial contamination of meat

Overfertilization of lakes and rivers from runoff of fertilizers, livestock wastes, and food processing wastes Pollution from pesticide

sprays

Since 1950, global meat production has increased fivefold and per capita meat consumption has doubled• As wealth and commerce increase, so does meat, milk,

and egg consumption

• Domestic animals raised for food increased from 7.2 billion in 1961 to 27.5 billion in 2011

• Meat consumption is expected to double by 2050

Consuming animal products has environmental, social, agricultural and economic impacts

Domesticated animals raised for food rose from 7.3 billion to 20.6 billion between 1961 and 2000• Mostly chickens

About half of the world’s meat is produced by livestock grazing on grass.

The other half is produced under factory-like conditions (feedlots).• Densely packed livestock are fed grain or fish meal.

Eating more chicken and farm-raised fish and less beef and pork reduces harmful environmental impacts of meat production.

Feedlots- factory farms/concentrated animal feeding operations• Large warehouses of pens designed to deliver energy-

rich food to animals living at extremely high densities

• Half of the world’s pork, poultry and beef come from feed lots

• https://www.youtube.com/watch?v=ayGJ1YSfDXs

Feedlots reduces the impact on landscape thus reducing soil degradation through overgrazing

However, feedlots are contributors to air and water pollution• Animal waste can pollute surface and groundwater One dairy cow can produce 44,975 lbs of waste in one year

To avoid disease animals are dosed heavily with antibiotics (can create antibiotic resistance in humans)

Fig. 13-21, p. 289

Trade-Offs

Animal Feedlots

Advantages Disadvantages

Increased meat production

Need large inputs of grain, fish meal, water, and fossil fuelsHigher profits

Concentrate animal wastes that can pollute water

Less land use

Reduced overgrazing

Reduced soil erosion

Antibiotics can increase genetic resistance to microbes in humans

Help protect biodiversity

Sustainable agriculture = agriculture that does not deplete soils faster than they form. It does not• reduce the amount of healthy soil

• pollute water

• decrease genetic diversityNo-till farming and other soil conservation

methods help make agriculture more sustainableReducing fossil-fuel inputs and pollution is a key

goal• Many approaches move away from the industrial

agriculture model

It is more efficient, energy wise, to eat lower on the trophic levels than to eat meat

In 1900, 10% of global grain went to feeding animals…….In 1950 20% was used

By the beginning of the 21st century , we were feeding 45% of global grain production to animals

Efficiency of converting grain into animal protein.

Figure 13-22

To increase crop yields, we can mix the genes of similar types of organisms and mix the genes of different organisms.• Artificial selection has been used for centuries to

develop genetically improved varieties of crops.

• Genetic engineering develops improved strains at an exponential pace compared to artificial selection.

Controversy has arisen over the use of genetically modified food (GMF).

https://www.youtube.com/watch?v=EzEr23XJwFY

Genetic engineering involves splicing a gene from one species and transplanting the DNA into another species.

Figure 13-19

The winged bean, a GMF, could be grown to help reduce malnutrition and the use of large amounts of inorganic fertilizers.

Figure 13-20

GMO- scientists directly alter the genes of organisms including crop plants and livestock• In the past we’ve used artificial selection/selective

breeding

GM crops are modified to be-• Herbicide resistant so farmers can spray herbicide on

weeds w/o killing their crops

• Pest resistant

• Ice resistant (strawberries)

GM foods are a big businessGlobally in 2012, 17 million farmers grew GM

foods on 170 million ha (420 million acres)—11% of all cropland• 90% of U.S. corn, soybean, cotton, and canola are GM

plants

Most GM crops are herbicide and pesticide resistant• Large-scale farmers grow crops more efficiently

Traditional breeding changes organisms through selective breeding of the same or similar species• Works with entire organisms in the field

• Genes come together on their own

• Uses the process of selection

Genetic engineering mixes genes of different species• Works with genetic material in the lab

• Directly creates novel combinations of genes

• Resembles the process of mutation

Controversy has arisen over the use of genetically modified food (GMF).• Critics fear that we know too

little about the long-term potential harm to human and ecosystem health.

There is controversy over legal ownership of genetically modified crop varieties and whether GMFs should be labeled.

Golden rice is a new genetically engineered strain of rice containing beta-carotene.

Can inexpensively supply vitamin A to malnourished.

Figure 13-1

Critics contend that there are quicker and cheaper ways to supply vitamin A.

Scientist call for more evidence that the beta-carotene will be converted to vitamin A by the body.

Figure 13-1

As GM crops expanded, scientists, citizens, and policymakers became concerned• Impacts on human health, but support of this has been elusive

Ecological concerns over escaping transgenes • They could harm non-target organisms

• Pests could evolve resistance

• They could ruin the integrity of native ancestral races and interbreed with closely related wild plants

Precautionary principle = idea that one shouldn’t undertake a new action until the effects of that action are understood

Concerns of GM crops include• GM plants could breed with the wild

variety found in nature = decrease in plant diversity

• GM plants could create “superpests”resistant to the GM “supercrops”

• Consequences of GM crops are still open for debate because it is newer technology Concern about possibly impacting human

health w/ altered proteins

Supports of GM crops claim they reduce carbon emissions by:• Fewer pesticide applications = tractors using less fuel

• Herbicide resistant crops encourage no-till farming then more carbon is sequestered in the soil

GM crop research suggests that GM crops reduced carbon emissions equivalent to taking 3.6 million cars off the road

Environmental Benefits:• Higher yields

• Promotes low-tillage techniques Decrease soil erosion

Decrease energy consumption from machinery

• Lower fertilizer requirement

• Reduce pesticide use

• Drought resistance crops reduce irrigation needs

Economic Benefits:• Produces higher yeilds

• Less money spent on pesticide, herbicide, fertilizer, water

• Increased nutritional value

• Low tillage techniques: Lower fossil fuels needed and released

• Less pesticide/herbicide use = decrease healthcare costs for farmers

Environmental Disadvantages:• Insect resistant crops could reduce beneficial insects

• Drought resistant and salinity resistant plants increases pressure to convert semi-arid land into farmland = decrease in biodiversity in those areas

• Lower genetic variability Wheat varieties in China have dropped from 10,000 in 1949

to 1,000 by 1970

Economic Disadvantages• Higher yields = increase in soil

depletion

• Produces sterile seeds Have patent seeds which must be

purchased annually (poor farmers unable to purchase)

• Cost of tracking and labeling GM crops in food supply

• Research and development

Ethical and economic (rather than scientific) concerns have largely driven the public debate

People don’t like “tinkering” with the food supplyWith increasing use, people are forced to use GM

products or go to special effort to avoid themCritics say multinational corporations threaten the

small farmerResearch is funded by corporations that profit if

GM foods are approved for use• Approval decisions may not match Environmental Impact

Statement findings (e.g., GM sugar beets)

GM crops have not eradicated hunger or helped poor farmers in developing nations• GM crops do not focus on increased nutrition, drought

tolerance, salinity tolerance, etc.

Unlike the Green Revolution, which was a public venture, the “genetic revolution” has been driven by corporate financial interests

Corporations patent transgenes and protect them • Monsanto has launched 145 lawsuits against several

hundred farmers for having transgenes in their fields without buying them from Monsanto

Widespread concern exists that organic foods will be contaminated by GM plants

Consumers in Europe have expressed widespread unease about genetic engineering• U.S. consumers have largely accepted GMOs

Europe blocked import of American agricultural products from 1998 to 2003 because of concerns about the products being genetically modified• The United States sued the European Union before the

World Trade Organization for hindering free trade

The Cartagena Protocol on Biosafety lays out guidelines for open information about exported crops

Some nations now demand that GM foods be labeled United States does not require labeling

• Large majority of Americans would like labeling

• Petition of over 1 million signatures asked the FDA to start requiring labeling

Labeling proponents: people have a right to know what they are eating

Labeling opponents: labeling implies that the food is dangerous

In countries where food is labeled, some products stopped being stocked due to consumer aversion

Sustainable agriculture-• Related to low-input agriculture that uses smaller

amounts of pesticides, fertilizers, growth hormones, water and fossil fuel energy

Organic agriculture• Do not use synthetic fertilizers, insecticides, fungicides

or herbicides

• Use biological approaches such as composting

Organic farmers can’t keep up with demand• U.S. consumers pay $29.2 billion in 2011

• Worldwide sales tripled from 2000 to 2010

Production is increasing. In 2011:• Nearly 2 million ha (4.8 million acres) in the U.S.

• 37 million ha (91 million acres) worldwide

• But still less than 1% of total agricultural land

Two-thirds of organic agricultural land is in developing nations• 30% of Mexico’s coffee production is organic

Fig. 13-33, p. 302

Solutions

Sustainable Organic Agriculture

More Less

High-yield polyculture

Soil erosion

Soil salinizationOrganic fertilizers

Aquifer depletionBiological pest control

Overgrazing

Integrated pest management

Overfishing

Loss of biodiversity

Efficient irrigation

Loss of prime cropland

Perennial crops

Crop rotationFood waste

Water-efficient crops

Subsidies for unsustainable farming and fishing

Soil conservation

Subsidies for sustainable farming and fishing

Population growth

Poverty

Results of 22 year study comparing organic and conventional farming.

Figure 13-34

Fig. 13-34, p. 302

Solutions

Organic Farming

Improves soil fertility

Reduces soil erosion

Retains more water in soil during drought years

Uses about 30% less energy per unit of yield

Lowers CO2 emissions

Reduces water pollution from recycling livestock wastes

Eliminates pollution from pesticides

Increases biodiversity above and below ground

Benefits wildlife such as birds and bats

More research, demonstration projects, government subsidies, and training can promote more sustainable organic agriculture.

Figure 13-35