in simplest terms, agriculture is an effort by man to move beyond the limits set by nature
TRANSCRIPT
In simplest terms, agricultureIs an effort by man to move
Beyond the limits set by nature.
In Ethiopia, 1985: thousands ofPeople were starving.
Lack of rain combined with soilDegradation and war had
Caused a major crop failure For the 2nd time in 15 years.
Finally the rains came…
And washed away millions of Tons of soil in the rivers.
That year 6000 square milesWere added to the north
African desert.
For the most part, People farm and eat corn,
Wheat and rice.
It is dangerous to rely on onlyA few plants, if something
Happens to them, then Millions will go hungry.
People need roughly 1300Calories per day to stay
Healthy.
These come in the form of Carbohydrates,
Proteins and lipids.
But even if people consume Enough Calories in the
Food they eat, they may Suffer from malnutrition.
Malnutrition is a conditionIn which people do not
Consume enough nutrientsNecessary for life.
As a result, About 1 in every 3 people on
Earth are malnourished, Mostly women and children.
Because the world’s populationIs increasing rapidly,
More food is needed each year.
However, if everyone in the worldToday was given an equal amount
Of food produced, No one would have enoughTo stay strong and healthy.
As a result, the food producedIs not evenly spread out
And many people dieOf starvation.
Grain production per person Has dropped in recent years.
Droughts are periods whenRainfall is less than average.
This contributes to starvationBy causing crop failure.
Famine is a food shortage so Widespread that it
Causes malnutrition In many people.
In an effort to increase crop Yields, new varieties of grain
Were introduced in manyDeveloping countries.
This was called the Green revolution.
These new varieties had a Much greater yield than the
Old varieties, and moreNutrients.
The green revolution only Worked on large farms Because it required lotsOf water and fertilizers.
The earth has a limited amountOf arable land, fertile land
That can be plowed To grow crops.
This amount is decreasingEach year.
This shortage of fertile Agricultural land threatens ourAbility to feed the population.
The basic techniques of farmingHave not changed:
Plowing, fertilization, Irrigation and pest control.
They have just grown to Bigger scales.
Soil that can support the rapidGrowth of healthy plants
Is called fertile soil.
Most plant grow in topsoil,The loose surface layer
Of the soil.
Fertile topsoil is composed ofRock particles, water, air,
Dead plants, dead animals,And animal excrement.
Living organisms also playA large role in fertile topsoil.
Soil that has taken a longTime to form is being lost
To erosion at an alarming rate.
Erosion is the wearing away ofTopsoil by wind and water.
In the US, about half of the Topsoil has been lost in
The last 200 years.
The loss of topsoil occursAll over the world.
In dry areas the soil is lost toDesertification,
This is when the landBecomes desert like.
Without water,Topsoil is easilyMoved by wind.
The dustBowl
New ways of doing old Things are changing farming.
in no till farming, the seeds of The next crop are planted in
Slits that are cut into the soil,Straight through the remains
Of the previous crops.
Low input farming is farmingWithout using a lot of
Energy, pesticides, Fertilizer or water.
This helps to stop salinization,When the soil is full of salt
From over-irrigation.
Scientists are studying old Plants in hopes that they
Will make our future better.
Amaranth can grow with Little water and create a
High protein grain.
Glasswort grows in salty Soils and can even be
Irrigated with salt water.
In North America, insects Destroy 13% of all crops.
An insect is just one kindOf pest.
A pest is any organism thatOccurs where you
Don’t want it, or in largeEnough numbers to cause damage.
Wild plants have more Protection from pests than
Do crops.
So people use pesticidesTo control them.
A pesticide is a substance thatKills pests.
Unfortunately, the pesticidesAffect a lot more than just
The pest they are designed to Kill, many harm people.
And, pest populations eventuallyEvolve resistance to many
Pesticides.
So many farmers are turningTo biological pest control.
They are using living organismsTo naturally control pests.
But the problem with these Living organisms is that they
Might disrupt an entire ecosystem
So now many farmers, and Very profitable companies,Have turned to genetically
Engineered plants.
