Post on 05-Jul-2015
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Chapter 12 – Agriculture and the Environment
Soil Texture
Soil Erosion
O - organic material
A – (top) minerals (bottom) E - zone of leaching
B – high in leached minerals from above
C – original parent material
SOIL STRUCTURE
Goals of sustainable farming 1.
2.
3.
4.
Sustainable farming practicesThe following reduce soil erosion: Contour plowing:
Terracing hill sides: Shelterbelts: Low or No Till Plowing (wind and water)
Crop Rotation (keeps nutrients)Rotating heavy feeders, moderatefeeders with soil builders
Cover Crops Plant during fallow(off) season. Keep nitrates from leaching out of topsoil Also keep soil orgs healthy and “fed” Prevents excess N from runoff into water
supplies
Pest Management Broad spectrum
Narrow spectrum
Integrated Pest Management (IPM)
Integrated Pest Management
Cranberry and damage: black headed fireworm:
Seasonal flooding to control it
Left photo: predatory mite (IPM) devouring a thrips, an agicultural pest.
Right photo: the thrips by itself.
IPM Aims at control not elimination Uses a combo of methods incl:
Biological control Certain insecticides Certain crop planting methods
GM Crops Superhybrid?
Terminator Gene
Gene transfer (transgenic crops)
Desertification
Some Causes of Desertification Poor farming practices
Overgrazing
Chemical poisoning of the soil
Kesterson Wildlife Refuge
Artificial wetlands Early 1980s
received agricultural drainage water
Was supposed to drain to sea, didn’t finish it (oops!)
Selenium accumulated in water
Over-irrigating to leach out salt buildup caused the problem
Normal embryo Classified a toxic
waste site
Looking at plans to continue drainage to sea
No eyesNo feet
Desertification Other Causes:
Diverting water –
Cutting trees –
Mining –
Changing weather patterns/ Global climate change
Desertification data
Who’s most immediately affected:
70 percent of the world's drylands are degraded
in the world are affected to some degree by desertification.
Globally it is estimated that the annual income lost in the areas affected by desertification =
Important Legislation 1985
Conservation Research Program Food Securities Act
1988 Sustainable Agriculture Research and
Education Program
UNCCD: 1996UN Convention to Combat Desertification100 nations ratified500 million dollars to fund projects to stop it
Factory Farming: Increasing production Antibiotics are commonly used in animal
production Animals are bred to grow faster and to be
more desirable for market. E.g chickens with more breast meat.
Synthetic hormones are approved for use Growth hormones Milk production hormones
Beef Production Feedlots Fed corn instead of grass Confined in a small area Fecal material accumulates. Disease spreads readily Chemicals used to control disease
Waste Production...
Water contamination Treatment required Odor/airborne problems Waste treatment regulations are more lax
than for waste from people.