Chapter 14Chapter 14Soil ResourcesSoil Resources

SoilSoil

Uppermost layer of Earth’s crust that Uppermost layer of Earth’s crust that supports plants, animals and microbessupports plants, animals and microbes

Soil Forming FactorsSoil Forming Factors Parent MaterialParent Material TimeTime ClimateClimate OrganismsOrganisms TopographyTopography

Soil CompositionSoil Composition (45%) ________ (45%) ________

__________ __________ ______________________

(5%) _________(5%) _______________________________________

(25%) _________(25%) _________

(25%) _________(25%) _________

Soil OrganismsSoil Organisms

Soil Soil organisms organisms provide provide ecosysteecosystem m servicesservices

Nutrient CyclingNutrient Cycling

Soil PropertiesSoil Properties

Soil ProblemsSoil Problems

1. ___________________1. ___________________ Caused primarily by Caused primarily by water and windwater and wind

Why a problem?Why a problem? Causes a loss in soil fertility as organic Causes a loss in soil fertility as organic

material and nutrients are erodedmaterial and nutrients are eroded More fertilizers must be used to replace More fertilizers must be used to replace

nutrients lost to erosionnutrients lost to erosion Accelerated by poor soil Accelerated by poor soil

management practicesmanagement practices

The Dust Bowl

Soil ProblemsSoil Problems

2. _________________________2. _________________________

Suppress plant diseases and pests.

Reduce or eliminate the need for chemical fertilizers.

Promote higher yields of agricultural crops.

Facilitate reforestation, wetlands restoration, and habitat revitalization efforts by amending contaminated, compacted, and marginal soils.

Cost-effectively remediate soils contaminated by hazardous waste.

Remove solids, oil, grease, and heavy metals from stormwater runoff.

Capture and destroy 99.6 percent of industrial volatile organic chemicals (VOCs) in contaminated air.

Provide cost savings of at least 50 percent over conventional soil, water, and air pollution remediation technologies, where applicable.

____________________________________________________________

____________________________________________________________

Soil ProblemsSoil Problems

3. Soil Salinization3. Soil Salinization Gradual accumulation of salt in the soil, Gradual accumulation of salt in the soil,

usually due to improper irrigation usually due to improper irrigation techniquestechniques

Soil ProblemsSoil Problems

4. Desertification ________________________________________

__________________________________ ________________________________________

__________________________________

Desertification Around the World

Desertification now threatens vast areas Africa China

The best way to avoid desertification: __________________________________________

________________________________

Modern Dust Clouds

2. Crop Rotation2. Crop Rotation __________________________________________________________________________________

______________________________________________________________________

Soil ConservationSoil Conservation

1. 1. ________________________________ Residues from Residues from

previous year’s crops previous year’s crops are left in place to are left in place to prevent soil erosionprevent soil erosion

Strip Strip CroppingCropping

Soil ConservationSoil Conservation

3. Contour Plowing3. Contour Plowing ______________________________________________________________________ Strip Cropping-Strip Cropping-

______________________________________________________________________________________________________________________________________________________

4. ______________4. ______________ ____________________________________________________________________________________

____________________________________________________________________

TerracinTerracingg

Preserving Soil FertilityPreserving Soil Fertility

Organic fertilizersOrganic fertilizers ________________________________________

__________________________________________________________________

____________________________________________________________________________________________________________________________________________________________________________________

Inorganic fertilizersInorganic fertilizers ______________________________________________________

______________________________________________ SolubleSoluble

________________________________________________ ______________________________________________________

______________________________________________ Problems:Problems:

__________________________________________ __________________________________________ __________________________________________ __________________________________________ __________________________________________

Soil ReclamationSoil Reclamation

Two stepsTwo steps1.1. Stabilize land to Stabilize land to

prevent further prevent further erosionerosion

2.2. Restoring soil to Restoring soil to former fertilityformer fertility

Best way to do Best way to do this is shelterbeltsthis is shelterbelts

Row of trees to Row of trees to reduce wind reduce wind erosionerosion

Soil Conservation Policies in Soil Conservation Policies in USUS Soil Conservation Act 1935Soil Conservation Act 1935

Food Security Act (Farm Bill) 1985Food Security Act (Farm Bill) 1985

Sustainable Use of Biological Wealth

Excluding cattle from riparian zones Flood protection Water conservation Habitat for wildlife Preservation of biodiversity

Riparian Restoration San Pedro River before and after

restoration