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10/11/2014
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http://www.google.com/imgres?imgurl=http://i153.photobucket.com/albums/s235/BobbieGS/All%2520Things%2520GREEN/GreenPeople-
1.jpg&imgrefurl=http://www.myspace.com/kawiboy636&h=325&w=467&sz=21&tbnid=CKOoEO_8DblD9M:&tbnh=92&tbnw=132&prev=/search%3Fq%3Dimages%2Bof%2Bgreen%2Bpeople%26tbm%3Disch%26tbo%
3Du&zoom=1&q=images+of+green+people&docid=q1DtvLjWp5hYoM&hl=en&sa=X&ei=lk-CT-mRC8aQiQLompycAw&ved=0CC0Q9QEwAw&dur=266
http://thevividedge.com/page/7/
Be great if people were green [had chlorophyll],
could face the sun and fix atmospheric carbon
to get energy, i.e., food!!!
Forests, Soils and Sustainability
https://www.facebook.com/bluemangroup
COMMENT: This is a topic of several science fiction
stories but hard to do in Seattle during cloudy days!!
• Soil is not DIRT
• Cookbook recipe 101: How to make a soil
• What happens when we disrupt a soil and move it
towards becoming dirt?
• Human health, SOILS and agricultural crops links
• Practice of Geophagy – animals, humans ingesting SOIL
• Why building civilizations needed intensive or industrial
agricultural and why this was bad for SOILS?
• Why do we manage soil carbon, e.g., What does organic
farming have to do with healthier Soils?
• BIO2 – Why too much soil carbon is bad for ecosystems
and human health
• Terra preta – 2,000 year ago experiment to add carbon to
soils in the wet tropics
Today’s Class Outline
10/11/2014
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TAKE HOME MESSAGE: Soil is not DIRT!!
http://www.youtube.com/watch?v=Dor4XvjA8Wo#t=10
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• A pound of dirt
• Some bugs and microbes
• A dash of dead organic materials [OM]
• etc
How about??
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Or Scientifically: Dirt + organisms + OM + … = SOIL
QUESTION? What happens when
we disrupt a soil and move it
towards becoming dirt?
FACT: Agriculture on fertile soil (especially on
floodplains in desert regions of the world)
allowed the first civilizations to become a reality,
e.g., moving beyond being nomadic
ANSWER:
Collapse of the first civilizations with loss of
agricultural production and migration of people
to other locations because unable to feed the
population
10/11/2014
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BRIEF JOURNEY INTO THE
PAST
How far back in time do we
have to go to find the roots of
ancient agriculture??http://www.google.com/imgres?imgurl=http://mesopotamia.mrdonn.org/meso08.gif&imgrefurl=http://mesopotamia.mrdonn.org/powerpoints.html&h=450
&w=480&sz=53&tbnid=Y9D6CKv0a8ZY6M:&tbnh=90&tbnw=96&prev=/search%3Fq%3Dimages%2Bof%2Bfarming%2Bin%2Bancient%2Bsumeria%2
6tbm%3Disch%26tbo%3Du&zoom=1&q=images+of+farming+in+ancient+sumeria&docid=RmPEfEXrzTsLzM&hl=en&sa=X&ei=IluCT6rfIImriQL10JWqA
w&ved=0CEAQ9QEwBg&dur=16567
ancient
Mesopotamia,
hanging gardens
Farming
in ancient
Sumeria
First civilization to practice intensive, year-round
agriculture and used basic agricultural techniques, e.g.,
• large-scale cultivation of land
• mono-cropping
• organized irrigation, and
• had specialized labor force to farm http://en.wikipedia.org/wiki/Sumer
The title "inventors of agriculture" belongs to the Sumerians, starting c. 5500 BCE [~7,000 years ago]
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What did the surplus of storable food
mean for the world’s first great
civilization?
Population didn’t to be nomadic to search
for food or grazing land for their animals
[accumulate excess product for off-season use, or to sell/barter]
More people to build the civilization, e.g.,
greater population density for the same land
area
An extensive, specialized farm-labor force -
division of labor into non-agricultural jobs,
e.g. rise of standing armies, politicians!!
Territorial expansion, conflicts between cities
9http://en.wikipedia.org/wiki/Sumer
10/11/2014
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BRIEF DETOUR
Where was
agriculture
located and
what made it
initially
successful??
http://en.wikipedia.org/wiki/File:Cities_of_Sumer_(en).svg
Map of Ancient Sumer and its cities
11
REMEMBER:
What happened to their
agricultural production??
Salt-affected soils are the 2nd
largest cause of soil degradation
(after erosion)
Salinization
12
10/11/2014
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Egypt developed its civilization
by farming the fertile Nile Valley:
(1)high population density
(2)diversification of labor so a
warrior class could fight &
expand Egypt’s territory
POINT: Demise of Egypt
civilization because fertile
soils needed for agriculture
to feed a larger population
was vulnerable to climate
change
Egypt dependent upon Nile
River agriculture in fertile
floodplain soils
Every year the Nile River began to rise in the
summer, covering the floodplain. But …
•11500 BCE: Too much rain for 500 years -
excessive flooding caused abandonment of
agriculture & return to nomadic existence
[fishing, hunting, gathering]
•3000-2800: Droughts - reduced rainfall by
~1-1.5m or 30% less flow was followed by
widespread unrest and the depopulation of
Nubia
•2250-1950: Droughts - Low inundations,
drying out of Lake Moeris
•1170-1100: Drought - Low inundations
accompanied by decline of the New
Kingdom
But too little rain or too much rain stopped
farming on floodplains in Egypt
Eastern
desertWestern
desert
Agricultural scene from
Ancient Egypt
REPEAT STORY:
Egypt developed their civilization
by farming the fertile Nile Valley
http://en.wikipedia.org/wiki/History_of_agriculture 15
BUT, collapsed when
unable to farm in the
floodplains of the Nile
contributed to famine!!
10/11/2014
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16
17
Humans are only as
healthy as the
nutrients they get
from the soil via the
food we eat
Every time we
harvest a crop, we
remove soil nutrients
which is why we have
to fertilize intensively
managed agricultural
fields
http://www.nytimes.com/imagepages/2007/08/01/health/adam/19343FoodLabelGuideforWholeWheatBread.html
Food
producers
recognize
importance
of
nutrients in
FOOD, e.g.
labels &
add
nutrients to
highly
processed
foods
18
Whole wheat
bread
Always look at the
serving size
This healthy, whole-
wheat bread is low in fat
and cholesterol
Fiber is a healthy
nutrient,
so you want AT LEAST
100% each day
10/11/2014
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Ultimate Geophagy!! Lets go get some salt or clay!!
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The red-and-green macaw eats
clay from exposed river banks,
allowing it to utilize nutrients in
harmful foods
Elephants go into caves to
scrape the cave walls for the
salts the rocks contain in
areas where vegetation is
low in sodium. NOTE –
Kristiina already talked about
this
http://en.wikipedia.org/wiki/Geophagy
http://geography.about.com/cs/culturalgeography/a/geophagy.htm; http://www.hobotraveler.com/photos/kenya/ruby-roasted-clay_photo.jpg
Class Reading on Geophagy By
Matt Rosenberg
• People around the world eat
clay, dirt or other pieces of the
lithosphere. Commonly found
in Central Africa, South U.S.
• Traditional cultural activity
during pregnancy, religious
ceremonies, or as a remedy
for disease
• Clay ingested in Africa
contains nutrients:
phosphorus, potassium,
magnesium, copper, zinc,
manganese, iron.
What is clay?
CLAY =
• fine-grained, firm earthy
material that is plastic
when wet and hardens
when heated
• consisting primarily of
hydrated silicates of
aluminum
• widely used in making
bricks, tiles, and pottery
Yolen Jeunky sold
mud cookies in Cite
Soleil, Haiti last fall
GEOPHAGY - Africa,
pregnant and lactating
women eat clay for
nutritional intake (during
pregnancy, body requires
20% more nutrients and
50% more during lactation)
Grandma’s
Georgia
White Dirt
10/11/2014
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Why building civilizations
needed to practice intensive or
industrial scale agricultural and
why this was bad for SOILS??
22
23
SOME ANSWERS:
Need to feed a larger population from a
smaller land base –while higher crop yields &
accelerated growth rates only possible with
fertilizers/pesticides
Agriculture labor force is small so agriculture
needs to be highly mechanized
Perception economics better with large,
centralized production systems
Unmanaged soils provide nutrients to plants in amounts related to
the soil’s nutrient supply capacity. This supply rate may limit plant
production in the amounts we want, i.e., we don’t grow enough to
feed people. Some solutions to increase food yields are:
GOAL!!
Organic farmIntensive
agriculture farm
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10/11/2014
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fuel - to power the equipment
fertilizer - natural gas as a hydrogen source for
the Haber-Bosch fertilizer-creation process; Nitrogen,
phosphorus, potassium (acronym NPK) critical factors
in plant growth
synthetic pesticides – control pests on
crops
intensive
http://en.wikipedia.org/wiki/Agriculture25
Petroleum!! Modern agriculture
totally reliant on petroleum. WHY?
26
Increase yields & growth rates in
intensive agriculture due to:
1. Mechanized
2. Monocultures – 1 plant species
3. Irrigation
4. Chemical fertilizers & pesticides
(petroleum based)
1
2
34
27
QUESTION: Why do we manage soil carbon? Why does Organic
farming produce healthier Soils?
http://www.motherjones.com/files/images/soil.jpg;
https://www.canaanusa.com/images/CFT_pics_hand
s_5_13_1012.jpg
What is the darker
color in the soil??
10/11/2014
10
Organic farming uses crop rotation, green
manure, compost and biological pest control
Organic
farmhttp://en.wikipedia.org/wiki/Organic_
farming
28
Organic farmining uses fertilizers & pesticides but excludes
or strictly limits use of:
manufactured (synthetic) fertilizers, pesticides
plant growth regulators such as hormones, livestock
antibiotics, food additives, genetically modified
organisms (GMOs), human biosolids (sewage), etc
QUESTION: What does Organic farming manage to produce
healthier Soils?
A HISTORICAL FACT:
Land cultivation for
agriculture has
decreased the
organic matter
content of a soil by
50%
29Photography by TVU © Sydney Catchment Authority
QUESTION: Why do we care if there is
less organic matter in the
soil??
ANSWER: Organic matter holds soil particles together to
resist erosion. Organic farming adds organic
matter to soils so less erosion.
NOTE: Erosion affects muddiness of water systems which
then could affect fish and other aquatic organisms.
http://www.mnn.com/earth-matters/wilderness-resources/stories/soil-erosion-increasing-global-warming-threat; Friday, February 17, 2012
30
Little
organic
matter in
soil,
southern
Mexico
10/11/2014
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QUESTION?
Which soil is
better and
more healthy?
Left? Or right?
ANSWER:
Left good for
agriculture but
right good for
forests but not
agriculture
QUESTION? Can
good are we at making or
building a soil to supports the
vegetation that you want
growing on it?? Learn from
kids!!
For the scientific
method YOU
NEED!
Unfortunately not
easy like shown
on left!
BRIEF INTERMISSION:
An experiment to create the
soil for the Biosphere 2 in
the Arizona desert
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TAKE-HOME MESSAGE - Too much
organic matter in the soil can be
unhealthy for humans living in a ‘closed
system’ (air-tight)
10/11/2014
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Biosphere 2 in Arizona
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Biosphere 2
3636
They got the rainfall right!
Atmosphere
to be
cleaned by
recycling
through the
agricultural
fields
10/11/2014
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BUT Needed to build a tropical soil since Arizona
does not allow the importation of tropical soils!!
Arizona is a desert with desert soils.
• Tropical forest soils are generally acidic
– Native Arizona soil is mostly alkaline,
so add Organic Matter (OM) to soil
• Decomposition of OM creates organic &
carbonic acids in soil decreasing soil pH
• So they added OM to the alkaline soil to
acidify it
• However too much OM was added to the
soil in the Bio2,
– microbes decomposed the OM,
releasing much CO2 while using lots of O2
3838
BUT CO2 was absorbed by the artificial rock formations so
there wasn’t a negative CO2 feedback loop to stop microbial
production of CO2; therefore microbes continued
decomposing OM, consuming O2, and releasing CO2.
3939
That may be OK if you are a microbe but not a HUMAN!!
10/11/2014
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Problems
• CO2 increases to 2000 ppm but leveled off around 800-1500 ppm (or 0.08 - 0.15%)
• O2 decreases from 21% to 15% (equivalent to living at 9000 foot elevation) and continued decreasing
4040
Kidney
stones
Not
enough
oxygen
SO WHAT DID PAST SOCIETIES DO WHEN
THEIR SOILS WERE LOW IN ORGANIC
MATTER??
MIGRATE SOMEWHERE ELSE??
NO, some didn’t!!
41
Terra preta – 2,000 year ago experiment to add carbon to
soils in the wet tropics
Early
Soil Scientists!
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10/11/2014
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Terra Preta (do indio)
or Indian black earth-like anthropogenic soil with
enhanced fertility due to its high levels of soil
organic matter (SOM) and nutrients (such as
nitrogen, phosphorus, potassium, and calcium)
embedded in a landscape of infertile soils
43
COMMENT: High SOM but not approaching the high
levels found in the Biosphere 2
44
Stable form of soil carbon made by humans ~2000 years ago
RESULT: they built a fertile layer of topsoil that is still
productive and valuable today
FACT: Globally made by a diversity of societies
FOUND in the Brazilian Amazon basin, other
regions of South America such as Ecuador
and Peru
but also Western Africa (Benin, Liberia) & in the
savannas of South Africa, Asia
Terra Preta: A 2000 Year Old Soil Experiment
(Steiner, 2002)
• Carbon dated at 800 B.C-500 A.D
• High Carbon
conc (9%); non-
Terra Preta soils
are around 1%
carbon
• Local farmers
prize Terra Preta
which yields as
much as three
fold crop yields
as surrounding
infertile tropical
soils.
45
10/11/2014
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What do we find in these anomalous black earths?
“Terra Preta” soil – has 2
½ times more organic
matter in the soil
46
Plus a bunch
of charcoal
Low carbon &
nutrient poor soil
47
The Secret Ingredient
Evidence that soils were
created by humans
add
charcoal
One consistent feature of terra preta sites:
47
(Steiner, 2002)
48
charcoalcharcoal
control
Note: taller corn plants when charcoal
added to soil compared to controls
10/11/2014
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TODAY: Terra
preta sites are
so valued they
are dug up &
sold as potting
soil
49
50
TAKE HOME
MESSAGES:
• A well managed soil is a GOOD SOIL
• A GOOD SOIL is a LIVE SOIL
• A LIVE SOIL is a RESILIENT SOIL
• A LIVE SOIL is not DIRT
• A LIVE SOIL makes humans HAPPY!!
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