Soil
By Cameron Miller, Alex Bruno, Luc
Shay and Brendan Weyhe
Irrigation Methods and
U.S./International Programs for the
Promotion of Soil Conservation
Irrigation Methods
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center pivot
drip
flood
furrow
gravity
rotation
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sprinkler
subirrigation
traveling gun
supplemental
surface
Center Pivot
• Good for sloped surfaces that aren’t possible
with surface methods
• Still has the necessity of surface drainage
• The common ¼-mile system irrigates 130 acres
• It is a towable system
• Good for crops such as soy beans
Drip
• Sprinklers are about 75% efficient while these are 90% or
higher
• Easy to install
• Easy to design
• Inexpensive
• Reduces plant disease levels associated with high levels of
moisture
• Works by applying water slowly directly to soil (with small
droplets of water)
• Water soaks into soil before it can be evaporated out
• Only applied at plants roots (which is where they need it)
Flood
• “Low-tech" method of irrigating crops
• Basically, collect water in a bucket and pour it onto the
fields
• Still one of the most popular methods of crop irrigation
• Water is pumped or brought to the fields and is allowed to
flow along the ground among the crops
• This method is simple and cheap, and is widely used by
societies in less developed parts of the world as well as in
the U.S.
• About one-half of the water used ends up not getting to
the crops
• Traditional flood irrigation can mean a lot of wasted water
Furrow
• The same thing as flood but instead of cover
the entire soil surface, a a partial surface
flooding method of irrigation
• Normally used with clean-tilled crops where
water is applied in furrows or rows of
sufficient capacity to contain the designed
irrigation system”
Gravity
• Irrigation in which the water is not pumped
but flows and is distributed by gravity
• Water is conveyed in ditches, then released
and allowed to spread over the area
• The drawback here is that the water is not
evenly distributed
• This system is not very suitable for tree and
shrub crops.
Rotation
• Has been implemented to counter watershortage problem
Sprinkler
• A method of applying irrigation water which is similar
to rainfall
• Water is distributed through a system of pipes usually
by pumping
• It is then sprayed into the air and irrigated entire soil
surface through spray heads so that it breaks up into
small water drops which fall to the ground
• Sprinklers provide efficient coverage for small to large
areas and are suitable for use on all types of properties
• It is also adaptable to nearly all irrigable soils since
sprinklers are available in a wide range of discharge
capacity
Subirrigation
• Also known as seepage irrigation
• A method of irrigation where water is delivered to the plant root
zone from below the soil surface and absorbed upwards
• The excess may be collected for reuse
• Subirrigation is used in growing field crops such as tomatoes,
peppers, and sugar cane
• Used in areas with high water tables such as Florida and in
commercial greenhouse operations
• Three basic types of subirrigation system are in general use for
potted plants in greenhouses:
– ebb-and-flow: bench-mounted enclosures holding pots are filled and
then drained
– trough: water is flowed through bench-mounted, slightly sloping
enclosures containing pots
– flooded floor: special sloped concrete flooring is flooded and drained
Traveling Gun
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Sprinkler irrigation system consisting of a single large nozzle that rotates and is
self-propelle
The name refers to the fact that the base is on wheels and can be moved by the
irrigator or affixed to a guide wire
Consists of a high capacity sprinkler mounted on a chassis to which a flexible hose
is connected (usually 3 to 5 inches in diameter and up to 1320 feet long)
The traveler is pulled along selected travel lanes by a cable or the hose wrapping
on a rotating reel.
The reel can be powered by a water turbine, water piston, or engine drive
The cable reel pulls the traveler through the field in a straight line.
Adapted to irregularly shaped fields
The costs are moderate and require less labor than other methods
Require high operating pressures and high power pumping units.
Alleyways are required in the crop.
Wind seriously affects the distribution pattern.
Supplemental irrigation (SI)
• Highly efficient practice
• Great potential for increasing agricultural production and
improving the dry rainfed areas
• In the drier environments most of the rainwater is lost by
evaporation
• The rainwater productivity is extremely low
• Water harvesting can improve agriculture by directing and
concentrating rainwater through runoff to the plants and
other beneficial uses
• Over 50% of lost water can be recovered at a very little cost
• Environmental benefits of this practice are far more
important than increasing agricultural water productivity.
Surface
• Systems apply water rapidly to a level or nearly level area
enclosed by dikes
• Accurate land leveling makes this system much more
efficient and effective
• This system is used extensively in the cranberry bogs for:
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frost control
freeze protection
bog management
irrigation.
• Water is retained at a uniform depth until it has been:
– taken into the soil
– has served its purpose of preventing freezing or frost damage
– the water harvesting is complete
U.S./International Programs for the
Promotion of Soil Conservation
• -The Food Security Act of 1985
• -The Conservation Reserve Program
• -Federal Agricultural Improvement and
Reform Act (“freedom to farm act”)
• Environmental Quality Incentive Program
• Natural Resources Conservation Foundation
The Food Security Act of 1985• Contains provisions designed to discourage the conversion
of wetlands into non-wetland areas
• These provision are commonly referred to as the
"Swampbuster" provisions
• Denied Federal farm program benefits to producers who
converted wetlands after December 23, 1985
• The Food, Agriculture, Conservation, and Trade Act of 1990
strengthened Swampbuster by making violators ineligible
for farm program benefits for that year and subsequent
years
• Created a system for inadvertent violations allowing
farmers to regain lost Federal benefits if they restore
converted wetlands
The Conservation Reserve Program
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The Conservation Reserve Program (CRP)
Provides technical and financial assistance to eligible farmers and ranchers to
address soil, water, and related natural resource concerns on their lands in an
environmentally beneficial and cost-effective manner
Provides assistance to farmers and ranchers in complying with Federal, State, and
tribal environmental laws, and encourages environmental enhancement
Funded through the Commodity Credit Corporation (CCC)
Provides technical land eligibility determinations, conservation planning and
practice implementation
Reduces soil erosion
protects the Nation's ability to produce food and fiber
reduces sedimentation in streams and lakes
improves water quality, establishes wildlife habitat
enhances forest and wetland resources
encourages farmers to convert highly erodible to vegetative cover
Farmers receive an annual rental payment for the term of the multi-year contract
-Federal Agricultural Improvement and
Reform Act (“freedom to farm act”)
• revises and simplifies direct payment programs for crops and
eliminates milk price supports through direct government
purchases
• removed the link between income support payments and farm
prices.
• It authorized 7-year production flexibility contract payments that
provided participating producers with fixed government payments
independent of current farm prices and production
• specified the total amount of money to be made available through
contract payments under production flexibility contracts
• The law increased planting flexibility by allowing participants to
plant 100% of their total contract acreage to any crop, except with
limitations on fruits and vegetables
The Environmental Quality Incentives
Program (EQIP)
• reauthorized in the Farm Security and Rural
Investment Act of 2002 (Farm Bill)
• provides a voluntary conservation program for
farmers and ranchers that promotes agricultural
production and environmental quality as
compatible national goals
• EQIP offers financial and technical help to assist
eligible participants install or implement
structural and management practices on eligible
agricultural land
Natural Resources Conservation
Foundation (NNRCF)
• a nonprofit private organization established by the
1996 farm bill
• promotes and funds innovative solutions to
conservation problems through effective partnerships
• The Foundation can accept gifts and raise money
• The NNRCF will conduct research, undertake
educational activities, support demonstration projects,
and make grants to state and local governments and
nonprofit organizations
• Similar foundations have been created for several
other natural resource areas.
Soil Characteristics
Soil Degradation
• Soil degradation occurs where our activities
(either directly or indirectly) cause it to
become less vigorous or less healthy.
• The ultimate degradation is the removal or
loss of its physical components.
Soil Erosion
• Degradation is not the same as soil erosion, which is
when the soil is washed or blown away by water or
wind.
• Soil erosion is common when trees are cut down,
and then it rains, so the soil is moved somewhere
else (sometimes to the sea/ocean/river).
• Trees and their root systems keep the soil in place
and thus prevent soil erosion.
Sheet Erosion
• Sheet erosion
commonly occurs on
recently plowed fields
or on other sites having
poorly consolidated soil
material with scant
vegetative cover.
Rill Erosion
• The formation of numerous, closely spaced
rills due to the uneven removal of surface soil
by streamlets of running water. Also known
as rilling; rill wash;
rillwork.
Gully Erosion
• Gully erosion is the
removal of soil along
drainage lines by surface
water runoff.
• Once started,
gullies will continue to
move by headward erosion
or by slumping of the side
walls unless steps are taken
to stabilise the disturbance.
Conventional Tillage
• Full width tillage which disturbs all of the soil
surface and is performed prior to and/or
during planting.
• There is less than 15 percent residue cover
after planting.
• Generally involves ploughing or intensive
(numerous) tillage trips.
• Weed control is accomplished with crop
protection products and/or row cultivation.
Soil Erosion as a Global Problem
• Soil erosion remains the world's biggest
environmental problem, threatening both developed
and developing countries, according to sources at the
12th International Soil Conservation Organization
(ISCO) Conference, which opened Monday in Beijing.
• Sources at the conference said that 65 percent of the
soil on earth display degradation phenomena, such
as erosion, desertification and salinization.
Desertification
• the extreme deterioration of land in arid
and dry sub-humid areas due to loss of
vegetation and soil moisture;
desertification results chiefly from manmade activities and influenced by climatic
variations.
The Dust Bowl (The Dirty 30’s)
• Period of severe dust storms
• Caused ecological and agricultural damage
• Caused by
severe drought
• Also caused by lack
of crop-rotation and
fallow fields
International Whaling Comission
• - Founded 1946, in Washington D.C.
• - Purpose is to govern the conduct of whaling throughout
the world
• - Responsibilities include:
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- providing complete protection for certain species
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- designate specific areas as whale sanctuaries
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- set limits on the numbers and size of whales which
may be taken
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- decides open and closed seasons for whaling
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- prohibits the capture of suckling calves and
females
accompanied by suckling calves
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http://www.iwcoffice.org/index.htm
Chico Mendes
• Rubber Trapper in Brazil’s Amazon Region
• In the 1980’s became politically active in
protecting the rights of Rubber Trappers against
the invasion of cattle ranchers
• Fought to stop the burning and logging of the
Amazon Rainforest
• Caught the attention of Environmentalists around
the world, but was murdered in 1988 by ranchers
who opposed him
http://www.chicomendes.com/
Soil
By Cameron Miller, Alex Bruno, Luc
Shay and Brendan Weyhe
What is Soil?
- Soil is a complex plant-supporting system
consisting of disintegrated rock, organic matter,
water, gases, nutrients, and microorganisms.
-Soil is a renewable resource, it renews itself over
a long period of time.
- Soil is the foundation for agriculture, it is vital
forestry, and for functioning the earth’s natural
systems.
What is Soil?
• By Volume, soil consists of about half mineral
matter, and up to five percent organic matter,
and the remainder consists of pore space
taken up by air or water
• Organic matter in soil includes both living and
dead microorganisms, as well as decaying
material derived from plants and animals.
What is Soil?
• As well as supporting plant growth, soil also
provides a habitat for animals such as
earthworms, insects, mites, millipedes,
centipedes, nematodes, sow bugs, and
burrowing mammals, amphibians, and
reptiles.
• Soil contains millions of bacteria, fungi, algae,
and protists.
• Soil is actually an ecosystem in itself.
How does soil form?
• Soil formation is a slow and complex process.
• It begins with Parent material as a base, which
can consist of lava or volcanic ash, rock and
sediment deposited by glaciers, wind blown
dunes, sediments deposited by rivers, lakes, or
oceans, or bedrock.
• The processes most responsible for soil
formation are weathering, erosion, and the
deposition/decomposition of organic matter.
How does soil form?
• Weathering describes the physical, chemical,
and biological processes that break down
rocks and minerals, turning large particles into
small particles.
How does soil form?
• Physical or mechanical weathering breaks down
rock. Two examples of Physical weathering are
wind and rain.
• Chemical Weathering results when water or
other substances chemically interact with the
parent material. Chemical weathering occurs
most with warm and wet conditions.
• Biological Weathering occurs when living things
break down parent material, for example lichens
may produce acid that weathers rock.
How does soil form?
• Weathering is just one process of soil
formation.
• Another process often involved is erosion.
• Erosion is the dislodging and movement of soil
from one area to another.
• Erosion can both bring new soil to depleted
areas, or deplete soil from rich areas.
The Horizons of a basic soil profile
• Soil consists of different layers known as
horizons.
• The distinct horizons as a whole make up a soil
profile.
• There are typically six major horizons in a soil
profile (O, A, E, B, C, and R).
• Although few soil profiles contain all six
horizons.
The horizons of a basic soil profile
• One of the most important horizons for
agriculture and ecosystems is topsoil.
• Topsoil is mostly inorganic mineral, with
organic matter mixed in.
• Topsoil is the most nutritive horizon for plants.
• It is also home to most of the living organisms
contained in soil.
Soils by Biome
• The regional differences in soil traits affect
agriculture.
• For example the soil in tropical rainforests is
very low in nutrition, where soil in temperate
grasslands is high in nutrition.
• Factors such as percepitation and temperature
affect the richness of soil.
Soil Characteristics
• There are four main characteristics of soil:
Color, Texture, structure, and pH.
Soil Characteristics
• Soil Color can indicate its composition and
sometimes it’s fertility.
• Before modern tests, farmers used the color
to determine the soil’s potential.
• Usually the darker the soil, the richer it is in
organic matter, whereas Paler soil indicates
low organic content.
Soil Characteristics
• Soil texture is determined by the size of the
particles in the soil and influences the ease or
difficulty of cultivation.
• There are three main categories of soil
texture.
• Clay consists of the smallest particles of soil,
then silt, and the largest sand.
• Loam is a soil type that consists of a mixture
of all three soil textures.
Soil Characteristics
• Soil texture also also influences porosity.
• Porosity is the measure of the size of spaces
between particles.
• The finer the texture, the smaller the spaces
between them and the harder it is for water
and air to travel through the soil.
• The best soil texture for agriculture is silt or
loam because it contains just the right amount
of porosity.
Soil Characteristics
• A Soil Triangle is a diagram used to classify soil
texture.
Soil Characteristics
• Soil structure is a measure of the clumpiness
of soil.
• Soil clumps that are too large can discourage
plant roots from establishing, where no
clumps at all can compact soil which reduces
it’s ability to retain water.
Soil Characteristics
• Soil pH is the acidity or alkalinity of the soil,
which determines the soil’s ability to support
plant growth.
• Too extreme of a pH will kill plants, but the
perfect balance will allow nutrient availability
and better plant growth.
Soil Characteristics
• Soil characteristics determine plant’s ability to
provide plants with nutrients.
• Cation Exchange is the process of which plants
acquire nutrients through.
• In Cation Exchange, soil particles containing
nutrient ions exchange them with hydrogen
ions from plants. The soil particles then
replenish through an exchange with soil water.
Soil Characteristics
• Different types of soil have different abilities
of holding cations.
• Soil rich in organic matter, low in acidity, and
fine in texture has the greatest cation
exchange capacity.
Soil Conservation
The Soil Conservation Service
• 1935- Pioneered measures to slow soil
degradation
• In response to Dust Bowl
• US Gov. passed Soil Conservation Act
• Established Soil Conservation Service
The Soil Conservation Service
• Assess land’s resources, problems, and
opportunities for conservation
• Use science to plan conservation
• Make sure conservation plans agree with land
user’s objectives
• Improve overall quality of life in region
Crop Rotation
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Alternate crops grown in a field
Return nutrients to soil
Prevent diseases in crops.
Common cycles include wheat/corn to
soybean/legumes (return nitrogen to soil).
• Reduces pests
Contour Farming
• Method of plowing furrows perpendicular to
the slope of a hill
• Prevents the formation of rills and gullies as
rainwater washes down it.
• Furrows act as mini dams, slowing the flow of
water and catching soil washed away by the
water.
Strip Cropping
• A way to minimize erosion by sowing rows of
different crops next to each other.
• Increased density of plant matter makes it
harder for soil to be washed away by rain
water.
Intercropping
• Method of planting different crops in same
field
• If a legume like soybeans is planted next to
other crops, the other crops flourish due to
the increased nitrogen-fixation by the
soybeans.
Alley Cropping
• Similar to intercropping
• Farmers plant nitrogen fixing plants inbetween other crops to promote soil fertility.
• Nitrogen fixing plants are planted in the
“alleys” between crops
Agro-Forestry
• Farmers allow trees to grow in farms with
their crops.
• Many positive effects to this method:
– If an area is too hot, the shade from the trees
reduces water evaporation.
– Increased biodiversity.
Shelterbelts
• Rows of trees or dense shrubbery planted
around a farm.
• The trees and shrubs block wind and prevent
erosion.
• Trees are harvested for wood or fruit.
Reduced tillage/no tillage
• a tractor pulls a “no till drill”.
• Leaves behind 15-30% of plant matter, slowing
the speed of water flow and reducing erosion.
Conservation Tillage
• Same method as reduced tillage except more
plant matter is left behind (30-40%).
• Decomposing organic matter reduces need for
fertilizer.
• Reduces amount of tractor driving, reducing
fuel consumption.
Poly-Varietal Cultivation
• Method of planting many different species of
crops on the same field at the same time.
• Beans, squash, peppers, etc all in same field.
• 25% of world’s cropland
Gully reclamation
• Gully- landform created by erosion of running
water over a period of time.
• Gullies can run through essential crop land.
• The process of reclaiming these gullies starts
with diverting the water flow so erosion stops.
• Filling in and making the land suitable for
crops again is very costly.
Land Classification
• land is classified by geology, topography, soils,
vegetation, climate conditions, living species,
water resources.
• Lets farmers know if land is sustainable for
crops or better for livestock.