Term
| percent of land used for agriculture |
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Definition
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Term
| 3 key concpets sustainablity |
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Definition
• Renewable and Non-renewable resources
• Carrying capacity
• Sustainable productivity |
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Term
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Definition
| max rate of use that can be sustained |
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Term
| how can we change carrying capacity? |
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Definition
-enhance input of capital
-reduce through deletion of resource |
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Term
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Definition
• Structure
• Erosion (wind, water)
• Loss of soil organic matter
• Salinization
• Compaction
• Acidification
Desertification |
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Term
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Definition
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Term
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Definition
Rainfall
Soil Erodibility
• Intensity
• Duration
• Texture
• Structure
Topography
Management
• Organic mater
• Slope
• Length
• Crop selection
• Tillage |
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Term
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Definition
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Term
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Definition
ground cover, residue
plant across slope
grassed water ways |
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Term
| universal soil loss equation: water erosion |
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Definition
A= R x K x LS x C x P
A = Estimated erosion at site
R = Rainfall factor
K = Soil erodibility factor
LS = Slope length and steepness factor
C = Cropping practices factor
P = Support practice factor |
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Term
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Definition
• Detachment
• Entrainment
• Transport
• Deposition |
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Term
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Definition
• Causes:
- wind speed: high
- soil texture: high content fine sand
- water content: low
- ground cover: little
- surface roughness low
• Impact:
- growing crop (“sandblasted”)
• Remedial measures:
- ground cover
- windbreaks |
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Term
| loss of soil organic matter causes: |
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Definition
• decreased input of OC (overgrazing)
• decreased use of forages in rotation
• decreased application of manure
• increased frequency of tillage
• erosion
• energy crops? |
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Term
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Definition
deterioration in soil structure (increased bulk density,
loss of porosity, increase soil resistance to penetration,
decreased aeration)
decreased infiltration
increased susceptibility to erosion
increased susceptibility to crust formation
reduced store of mineralizable N
reduced CEC |
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Term
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Definition
• minimize traffic by heavy
equipment when soils wet
• tillage?
• use of deep-rooted crops?
• maintain organic matter
content |
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Term
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Definition
cumulative direction of soil water flow upwards
climate: high evaporative demand
soil parent material: saline
crops: shallow rooted crops
irrigation water: high salt content, inadequate
drainage |
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Term
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Definition
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Term
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Definition
loss of large pores
increase soil resistance to
penetration
decreased aeration
decreased infiltration
increased susceptibility to
erosion |
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Term
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Definition
plants experience “drought” stress
some solutes may reach toxic levels
deterioration of soil structure |
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Term
| salinization remidial mesure: |
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Definition
improve water use efficiency
improve drainage
grow deeper rooted crops
grow cultivars more tolerant of high salt content
improve quality of irrigation water |
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Term
| acidification causes, impact and remdies |
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Definition
Causes:
- acid rain
- NH4 fertilizers
• Impact (particularly on soils with low CEC, no
carbonates present):
- decreased availability of P
- metal toxicity
- diminished biological activity
• Remedial measures:
- addition of lime |
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Term
| desertification causes, impact and remdies |
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Definition
End result of soil degradation
causes:
decreased ground cover
impact:
• - decreased productivity
• Remedial measures:
- increased ground cover |
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