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

• center pivot• drip• flood• furrow• gravity• rotation

• 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 water-shortage 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• 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:

– 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• 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 man-made 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:• - providing complete protection for certain species• - designate specific areas as whale sanctuaries• - set limits on the numbers and size of whales which

may be taken• - decides open and closed seasons for whaling• - prohibits the capture of suckling calves and

females accompanied by suckling calves• 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

• 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 in-

between 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.