Transcript Agriculture: Then and Now - Appoquinimink High School

Agriculture: Then and Now
Agriculture: Then
• was developed at least 10,000 years ago
• Evidence points to the Fertile Crescent of the
Middle East as the site of the earliest planned
sowing and harvesting of plants that had
previously been gathered in the wild.
• Independent development of agriculture is
also believed to have occurred in northern
and southern China, Africa's Sahel, New
Guinea and several regions of the Americas.
Agriculture: Now
• Farming changed very little from early times
until about 1700.
• In the 1700's an agriculture revolution took
place which led to a large increase in the
production of crops.
• In the 1850's, the industrial revolution spilled
over to the farm with new mechanized
methods which increased production rates.
Early on, the large changes were in
the use of new farm
implements. Most of these early
implements were still powered by
horse or oxen.
These new implements combined
with crop rotation, manure and
better soil preparation lead to a
steady increase of crop yield in
Europe.
The agricultural revolution was
a period of agricultural
development between the 18th
century and the end of the
19th century, which saw a
massive and rapid increase in
agricultural productivity and
vast improvements in farm
technology.
Two major types of agriculture
Conventional agriculture
Sustainable agriculture
Conventional agriculture
•
•
•
•
most commonly practiced in the United States
altering or changing the natural environment
installing an irrigation system
mono-cropping, or planting one crop (ex: only corn is
grown in a plot).
• the crops grown are nonrenewable
• diversity is eliminated in order to maintain uniformity
using insecticides and pesticides to keep insects and
animals from eating the crops
• using inorganic fertilizers to provide nutrients to the
soil a lot of energy and work for the farmer to maintain
this unnatural farming system;
Sustainable agriculture (agro-ecology)
• uses ecological principles to farm
• maintaining the natural environment and using ecological principles
for sustained farming practices poly-cropping
– (ex: planting rows of corn, bean, and squash together rather than
in separate plots, like in mono-cropping) since many plants are
planted together, and each one has a different harvesting period,
the plot is never bare.
• reduces soil erosion
• diversity is maintained
• Plants are natural insect repellents. eliminates the need to use
insecticides.
• nutrients from each intercrop plant provide different nutrients to the
soil
• less energy is required from the farmer because the agriculture
system sustains itself
Agricultural Issues
Conventional agriculture
Sustainable agriculture
Conventional Agriculture Issues
• Erosion
– However, farming increases this process 18 times faster than nature
– Soil erosion can result in polluted water.
• Pesticide use
– 940 million pounds of pesticides are applied annually to fields, but only
10% reach their target
– The other 90% contaminate ground and surface water, harming humans
and wild life.
– Nutrients are added to fields through fertilizers with the intention of
increasing crop production. However, crops can only absorb one-third to
one-half of the nitrogen in fertilizers
• Energy Use
– Approximately 17% of energy used in the United States goes into food
production, distribution, and preparation
– The average piece of food consumed in the US has traveled an
estimated 1400 miles, and one-third of fruits and 12 percent of
vegetables come from abroad
Sustainable Agriculture Issues
• present there is little evidence one way or the other for
the claim that organic food is necessarily safer or better
for health
• the lower yields and decreased efficiency in organic
farming require more land (approx three times as
much) to produce the same amount of crops.
• traditional techniques such as crop rotation, compost
and manure to supply the soil with nitrogen and other
minerals would have required a tripling of the area
under cultivation.
• organic farming actually requires more energy per ton
of food produced, because yields are lower and weeds
are kept at bay by plowing
Bibliography
• http://watershed.allegheny.edu/comps/04maureencopeland/conventional_ag.htm
• http://www.economist.com/node/8380592?st
ory_id=8380592
• http://kids.mongabay.com/lesson_plans/lisa_
algee/agriculture.html