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http://www.extremepumpkinstore.com/ecom-catshow/soilconditioner.html

Soil

• Is a complex plant-supporting system

made up of rock, remains and waste of

organisms, water, gases, nutrients, &

microorganisms.

http://www.growfreshorganics.com/soil-building-of-better-soil

Humus

Partially decomposed organic matter

Micro-organisms

• maintaining soil fertility, productivity and

cycling of nutrients.

• Examples fungi, bacteria

Soil Characteristics

• Color- Darker usually indicates humus and

nutrients

• Texture – Based on particle size

Clay, Silt, Sand

Our soil tests

• pH- soil’s acidity or alkalinity

Best if 6 to 7.5

• Nitrogen – Produces protein and nucleic

acid.

• Phosphorus – storage and transfer of

energy through the plant.

• Potassium – improves the plants ability to

withstand extreme temps, drought and

pests.

Fertilizer

• Any material added to a soil to supply

plants with nutrients essential to the

growth of plants.

Agriculture

Traditional Agriculture

• Biologically powered agriculture

Industrial Agriculture

• Mechanized farming technology, the fossil

fuels, manufactured chemicals, and

irrigation.

Industrialized Agriculture

Green Revolution (1950-1970)

To obtain high yields:

• Plant monocultures (one type of plant).

• Input pesticides and fertilizers.

• Increase frequency and intensity of

cropping.

Wheat and corn

(industrial agriculture)

Rice (Intensive

agriculture)

Livestock

• Cattle – beef = affluence

• Horses

• Oxen

• Sheep

• Chicken

• hogs

http://www.youtube.co

m/watch?v=p_pLy7Gjl

ww

Cattle Ranching

Beef Cows

Dairy Cows

Trade-Offs

Inorganic Commercial Fertilizers

Advantages Disadvantages

Do not add humus to soil

Reduce organic matter

in soil

Reduce ability of soil to

hold water

Lower oxygen content of

soil

Require large amounts of

energy to produce,

transport, and apply

Release the greenhouse

gas nitrous oxide (N2O)

Runoff can over fertilized

nearby lakes and kill fish

Easy to transport

Easy to store

Easy to apply

Inexpensive to produce

Help feed one of every

three people in the

world

Without commercial

inorganic fertilizers,

world food output could

drop by 40%

Eutrophication

• accumulation of nutrients that support a

growth of algae, depleting the shallow

waters of oxygen.

Pesticides

• Chemicals that kill insects, microorganisms,

or weeds

A.K.A. – herbicides, insecticides, fungicides

• Summary: A look at corn pests including the corn earworm, corn borer, and wire worm.

Wheat plant infested with greenbugs.

DDT

• Dichloro-diphenyl-trichloro-ethane

• Developed first of the modern synthetic

insecticides in the 1940s.

• 1972, EPA bans DDT based on adverse

environmental effects.

DDT Saving Lives

George Silk/Time Life/Getty

Children playing in a DDT fog left

behind by a spraying truck

http://www.youtube.com/watch?v

=gtcXXbuR244

http://www.youtube.com/watch?v

=nP3ZLNSJu5g

Bioaccumulation occurred!!!

Humans & DDT

• Difficult for DDT to be absorbed through

human skin.

• 1968 Americans consuming an average of

0.025 milligrams of DDT per day!

• High concentration leads to headaches,

nausea, vomiting, confusion, and tremors.

Superbugs

• Insects become resistant to pesticides.

Hybrid Plants

• any offspring resulting from the mating of

two genetically distinct individuals

Fragaria x ananassa is the scientific name

for commercial strawberries, a cross

between Fragaria chiloensis and F.

virginiana.

Example: Red and Yellow corn cross-pollinated to yield several color

kernels on the same plant.

Example: Short ear corn with big kernels cross-pollinated with long ear corn

with small kernels to get long ear with big corn kernels.

Genetically Modified Foods

(GMO’s)

• are plants or animals created by gene

linking of biotechnology

• DNA from different species combine to

create plant, animal, bacterial and viral

genes that cannot occur in nature.

Example: Corn with Bt, a pesticide, added is likely to kill bugs

1990 Organic Food Protection Act

National standards for “organic”.

USDA states to be organic it CANNOT be:

• Genetically engineered/modified;

• Fertilized with municipal sludge;

• Zapped with radiation

Pesticides Residue

• 12 Least Contaminated

• Onions

• Avocado

• Sweet Corn (Frozen)

• Pineapples

• Mango

• Asparagus

• Sweet Peas (Frozen)

• Kiwi Fruit

• Bananas

• Cabbage

• Broccoli

• Papaya

12 Most Contaminated

Peaches

Apples

Sweet Bell Peppers

Celery

Nectarines

Strawberries

Cherries

Pears

Grapes (Imported)

Spinach

Lettuce

Potatoes