soil survey map reading
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Soil Survey Map Reading. Discussion and Activity Environmental Science. Soil As A 3- Phase System. Soil Particles Water Films and Trapped Gases in Pores Solids and Aggregates. Water is the Driving Force. Water Movement affects: A. Detachment B. Transport C. Deposition. - PowerPoint PPT PresentationTRANSCRIPT
SOIL SURVEY MAP READING
Discussion and ActivityEnvironmental Science
Soil As A 3- Phase System Soil Particles Water Films and Trapped Gases in Pores Solids and Aggregates
Water is the Driving Force
Water Movement affects: A. Detachment B. Transport C. Deposition
Types of Erosion Affecting Soil Quality
Rill and Inter-rill
Gully (most aggressive)
Splash
Gully Erosion
Inter- rill Erosion
Splash Erosion
How Does Soil Form?
Physical and Chemical Weathering
Wind and Water Mixtures and Solvents
What is Soil Composed Of?
Rocks and MineralsLiving Organisms = worms, bacteria, insects, fungiDecayed Organics= plants and animalsAggregates= rocks and pebblesMoistureTrapped Gases= air, methane, others
Types of Soils
LOAM is bestFor
SOIL FERTILITY
Soil Type Nitrogen Phosphorus Potassium pH
Garden (J) trace very high 8
Garden (R) trace high + very high7.5
Cornfield low high very high 7
Soybean field trace high low 8
How is Soil Loss Estimated?
Use of Soil Loss Equation= USLE
A= avg. annual soil loss tons/acre
R= rainfall runoff erosivity index based on geographical location
K= soil erodibility considers residue, bare vs. grass coverage, amt. of tillage, etc.
LS= slope steepness and length factor considers amt of slope; increase slope means increase soil loss
C= cover management
P= conservation practice (s) implemented
Soil DegradationPrimarily caused by:a. Poor farming practicesb. Overgrazing on ranched landc. Forestry practices that damage soil by clear cuttingd. Desertification= over 10% loss of productivity due 1. erosion 6. salt build up 2. compaction 7.climate change 3. removal of trees 8.water sources
depleted 4. overgrazing 9.misc. 5. drought conditions
Usually arid lands most susceptible to the above.
Soil Conservation Policies
Post Dust Bowl Era taught us how to conserve soil and change soil conservationPractices. Local to national levels of development of management and organizations enabled new policies to form and be set in place.
Policies that were Made
1. 1935- Soil Conservation Act established Soil Conservation Service to Work directly with farmers to develop plans for their land.
Policies/ Management
1994- SCS became the Natural Resources Conservation Service this allowed for better management of soil AND water conservation for protection of water ways and reduce effects of pollution and run off issues.
Policies/Management
CRP- Conservation Reserve Program began with the 1985 Farm Bill goal to stop farming crops and replace with grasses and tress to create biodiversity, water retention, less run off, and soil preservationIn addition, farmers are paid for conservation efforts
USDA estimate (according to text) that each dollar spent Saves nearly 1 ton of top soil
Policies/Management
Internationally, conservation efforts are also in place.
United Nations
Food and Agriculture Organization subdivision of Farmer’s Centered Agricultural Resource Management Program FARM focus on developing nations to increase crop yields, better management and farming practices
How Does Soil get Polluted?
1. Irrigation – over saturation causes root rot leading to soil erosion
2. Salinization- build up of salts in upper soil horizons from lower pulled
up by capillarity or by water sources in irrigation systems
How Does Soil get Polluted?
Acid Rain Precipitation- percolation through the soil is taken up by root systems
Pesticides- over use and accumulation of residues kill plants and animals, fungalSpores, bacteria, some that are helpful for the organic base of soils In addition, Toxicity levels affect human health.
Alternatives/ New Trends in Soil Conservation Efforts
Go green! Green Revolution means less chemical use
Better technology in use of equipment
Biotechnology in crops to reduce infestations and diseases
Biological Pest Control PracticesHow Does Soil get Polluted?