Download Organic fertilizers

Chapter 14
Soil Resources
Soil


Uppermost layer of Earth’s crust that
supports plants, animals and microbes
Soil Forming Factors





Parent Material
Time
Climate
Organisms
Topography
Soil Composition


(45%) ________
__________
___________
(5%) _________
_______________

(25%) _________

(25%) _________
Soil Organisms
Soil
organisms
provide
ecosystem
services
Nutrient Cycling
Soil Properties
Soil Problems

1. ___________________


Why a problem?



Caused primarily by water and wind
Causes a loss in soil fertility as organic
material and nutrients are eroded
More fertilizers must be used to replace
nutrients lost to erosion
Accelerated by poor soil management
practices
The Dust Bowl
Soil Problems

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 Problems

3. Soil Salinization



Gradual accumulation of salt in the soil,
usually due to improper irrigation techniques
_______________
_______________
_______________
_______________
Soil Problems

4. Desertification


_____________________________________
_____________________________________
_____________________________________
_____________________________________
Desertification Around the
World

Desertification now threatens vast areas



Africa
China
The best way to avoid desertification:

_____________________________________
_____________________________________
Modern Dust Clouds
Soil Conservation

1. ________________


Residues from previous
year’s crops are left in
place to prevent soil
erosion
2. Crop Rotation

______________________________________
______________________________________
Soil Conservation

3. Contour Plowing


Strip Cropping
___________________________________
Strip Cropping______________________________________
Terracing
_____________________________________

4. ______________

______________________________________
______________________________________
Preserving Soil Fertility

Organic fertilizers


__________________
__________________
_________________
__________________
__________________
__________________
__________________
__________________

Inorganic fertilizers


_________________________
_________________________
Soluble



________________________
_________________________
_________________________
Problems:





_____________________
_____________________
_____________________
_____________________
_____________________
Soil Reclamation
Two steps

1.
2.
Stabilize land to
prevent further
erosion
Restoring soil to
former fertility
Best way to do this
is shelterbelts


Row of trees to
reduce wind erosion
Soil Conservation Policies in US

Soil Conservation Act 1935

Food 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