“the way we eat has changed more in the past 50 years than in the past 10,000 years.”

“The way we eat has changed more in the past 50 years than

in the past 10,000 years.”

Remember the lesson of the Inca!

Monoculture

Polyculture

Polyculture

Corn, wheat, soy and rice…60% of human food supply.

What 3 crops provide most of the world’s food?

Subsidy or Subsidize

• assistance paid to a business or economic sector

• Most subsidies are made by the government to producers or distributors to prevent the decline of that industry

• Crops subsidized in the U.S.:

• Corn, rice, wheat, milk, soybeans, sugar, tobacco, cotton

Corn

• Cheap corn = lots of corn!

• Broken down in lab into lots of chemicals used in food.

• Subsidies make the unhealthy food cheap.

Reason #3 to protect biodiversity: Agricultural

Of 80,000 known edible plants on the planet, we depend on 20 species to provide 90% of global food supply.

Corn, rice, soy and wheat are 60% alone!

Pests and diseases generally are plant-specific.

• Examples –

• Boll weevil attacks cotton plants

• Rust fungus attacks corn

• Yellow rust fungus attacks wheat

Conventional agriculture relies heavily on petroleum

• Weighing in at 1,250 pounds (567 kilograms), Marina Wilson's champion steer Grandview Rebel is ready for auction at a county fair in Maryland. Raising this steer has taken an agricultural investment equal to 283 gallons (1,071 liters) of oil, represented here by the red drums. That includes everything from fertilizers on cornfields to the diesel that runs machinery on the farm. Overall, it takes three-quarters of a gallon of oil to produce a pound of beef

Pesticides – “To use or not to use?”

Pesticides to know

• 1st generation – derived from plants/minerals found in nature– Sulfur (used on wine

grapes)– Arsenic (rodenticide)– Rotenone modern

insecticide from tropical legume

– pyrethrum (insecticide derived from chrysanthemums)

• 2nd generation – created in labs, not found in nature– Atrazine (insecticide

used on more US corn crops)

– Glyphosate (Roundup)– DDT dichlorodiphenyltrichloroethane

DDT – the first of the second generation WW II Pacific theater -

1939Persistent contact

insecticide applied in farms and cities

1960’s – decline in Bald Eagles – unable to deposit Ca+ in egg shells

Bioaccumulation leads to biomagnification

(storing fat soluble chemicals in fat cells of body)

(concentration of toxins up the food chain)

Rachel Carson

Silent Spring 1962Controversy – makers

of DDT not happy with her work, tried to prevent publication of the book.

Died of breast cancer 1964

Led to banning of DDT use in US in 1972

DDT still used in Africa to combat malaria

Banned for agricultural use, but used to save human lives

Trade offs!US is #1 maker of

DDT in the world still (we just don’t use it on our land!)

Genetic resistance

Pests develop resistance to pesticide through genetic resistance

Increased dosage, application schedule, increased toxicity required to keep killing pests

The pesticide treadmill

Be target specificHarm no other speciesDisappear or break down after doing its jobNot cause genetic resistanceBe more cost effective than doing nothing

Ideally, a pesticide would . . .