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.