Ch 10: Agriculture, Biotechnology, and the Future of Food

Case Study – Oaxaca, MexicoThe Race to Feed the WorldPests and Pollinators

Case Study – Possible Transgenic Maize in Oaxaca, Mexico

• Corn was domesticated in Oaxaca 5500 years ago

• Native varieties serve as reservoirs of genetic diversity that we may need to sustain or advance our agriculture

• In 2001 it was found that the genes of GM corn (transgenes) had appeared in the genes of native maize, which caused widespread concern

• Another study conducted in 2003-04 found no transgenes at all :/

• How does genetic modification of crops affect people and the environment?

http://www.spiritofmaat.com/announce/gecornmex.htm

The Race to Feed the WorldWe are producing more food per person

• Over the past half century, our ability to produce food has grown faster than the global population

• But because of political obstacles and distribution inefficiencies, 850 million people in developing countries don’t have enough to eat (down to 13% from 26% in 1970)

The Race to Feed the WorldWe are producing more food per person

• Scientists & policymakers pursue a goal of food security, the guarantee of an adequate and reliable food supply for all people at all times —Devote more fossil fuel energy to agriculture —Plant and harvest more frequently —Increase the use of irrigation, fertilizer, and pesticides —Increase the amount of cultivated land —Develop more productive crop and livestock varieties

The Race to Feed the WorldWe are producing more food per person

• However, grain production per person has decreased 9% since 1985 (varies by region)

• Nearly all the planet’s arable land has been claimed

• There is no guarantee that food production will continue to outpace population growth

http://www.economist.com/node/18200618

The Race to Feed the WorldWe face undernourishment, overnutrition, and malnutrition

• Undernourishment in developing countries – an economic problem (low incomes… half the world population lives on < $2/day). About a billion undernourished people. 31 million Americans are “food insecure”

• Overnutrition in developed nations – abundance of food, cheap junk food, sedentary lifestyles

• Malnutrition – shortage of nutrients the body needs. Can affect both undernourished and overnourished individuals

The Race to Feed the WorldThe “green revolution” boosted agricultural production

• The desire for greater quantity & quality of food led in the mid- and late-20th century to the green revolution

• In the 1940s Norman Borlaug introduced a special strain of wheat to Mexico, which soon tripled wheat production

• Other developing nations followed – India, Pakistan, etc. (saved India from famine in 1970s)

“… A temporary success in man’s war against hunger and deprivation.”

http://opinionator.blogs.nytimes.com/2011/03/08/sustainable-farming/?smid=tw-NYTOpinionator&seid=auto

“These and other developments in the field of agriculture contain the makings of a new revolution. It is not a violent Red Revolution like that of the Soviets, nor is it a White Revolution like that of the Shah of Iran. I call it the Green Revolution.”

—William Gaud, USAID director. 1968

The Race to Feed the WorldThe “green revolution” boosted agricultural production

• Development of high-yielding varieties (HYVs) of cereal grains• Expansion of irrigation infrastructure• Modernization of management techniques• Distribution of hybridized seeds, synthetic fertilizers, and pesticides to

farmers (preexisting technologies)

The Race to Feed the WorldThe green revolution has brought the environment both benefit and harm

Benefit• Higher yield• Reduced pressures to convert

additional natural lands for new cultivation

• The planting of crops in monocultures has made planting and harvesting more efficient

Harm• Intensive application of water,

fossil fuels, inorganic fertilizers, and synthetic pesticides worsened pollution, erosion, salinization, and desertification

• Monocultural planting has reduced biodiversity over huge areas, increased susceptibility to disease, and narrowed the human diet

Questions to consider

• Has the green revolution solved problems, delayed our resolution of problems, or created new ones?

• How sustainable are green revolution approaches?

Pests and Pollinators *Pests and weeds pose have always posed problems for

A pest is any organism that damages crops that are valuable to people.

A weed is any plant that competes with crops

These organisms are simply attempting to survive and reproduce – There is truly no “malice” in their existence/actions

Thousands of Chemical Pesticides

• Aimed to kill: – Insects (insecticides)– Plants (Herbicides)– Fungi (Fungicides)– Organisms (Pesticides)

• More than $32 billion is spent every year on pesticides, 1/3 of which is spent in the U.S.

• About 400 million kg of active ingredients from pesticides are applied in the U.S. every year

Growing Resistance to Pesticides

• Apart from the toxicity of the previously mentioned chemicals, usefulness declines over time as pests evolve resistances to them

• Any gene that promotes an immunity to a specific chemical may be shared through reproduction

• “Revolutionary Arms Race” occurs between industrial chemists and the pests they battle to find/use stronger chemicals

Biological Control• Biological Control, or Biocontrol, operates on the principle

that “the enemy of one’s enemy is one’s friend”• Essentially Introduces organisms to help fight others

• Cactus moth introduced to Australia to fight Prickly Pear Cactus

• Bacillus thuringiensis (Bt) – Naturally occurring soil bacterium that produces a protein that kills caterpillars and the larvae of flies and beetles

– Spores are sprayed on crops for protection

Biocontrol can be Harmful• In some cases, biocontrol agents have become invasive and

unintentionally harmful to other organisms• Due to the success of the previously mentioned cactus moth, it was

introduced to the Caribbean, and then spread to Florida and is now destroying native cacti there.

• If Biocontrol works, it can be permanent in solving the problem, but if it fails the harm done can also be permanent

Integrated Pest Management• Realizing the drawbacks of both chemical use and Biocontrol,

farmers attempted to develop more sophisticated strategies• Integrated Pest Management- integration of various

techniques in order to achieve long-term suppression of pests, including Biocontrol, chemical use (if necessary), habitat alteration, crop rotation, transgenic crops, alternative tillage methods, and mechanical pest removal

• This method has become popular around the world in recent decades

Pollination• Pollination- The process by which male sex cells of a plant

(pollen) fertilize female sex cells of a plant; recognized as the botanical version of sexual intercourse– Can be influence by wind, or insects can play a role– Conservation is vital:

• Population of honeybee is declining– Honeybees pollinate over 100 crops that make up 1/3 of the

U.S. diet, therefore contributing billions of dollars in services

• Farmers and homeowners can reduce or eliminate pesticide use in order to help maintain populations of pollinating insects

(>^.^)>THE END!!!<(^.^<)