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?