By:Priscilla Arevalo

Angelica AlvaradoAlyssa Megan

Eileen Gao

SOIL AND AGRICULTURE (P.229-233)

WHAT IS A SOIL PROFILE?

Organic

Topsoil

Elluviation

Subsoil

Bedrock

Weathered P.M.

SOIL PROPERTIESSoil ColorSoil Texture

ClaySiltSandLoam

Soil StructureSoil pH

CATION EXCHANGE IS VITAL FOR PLANT GROWTH

• Soil characteristics vary from place to place.• Some regions have more fertile soils than others.

Tropical Rain Forest

Temperate Grassland

REGIONAL DIFFERENCES IN SOIL TRAITS CAN AFFECT AGRICULTURE

HUMAN PRACTICES THAT HAVE INCREASED VULNERBILITY OF SOIL

• Erosion: human activities have increased by 10-40 times rate of erosion occuring globally

• Human practices:

1.Industrial agriculture2.Deforestation3.Roads4.Climate change5.Urban spraw

DEGRADATION OF SOIL

1. Mulching

2. Contour Barriers

3. Rock Dams

Conservation Measures:

The largest areas of concern: Asia & Africa.Central America has highest percentage/worst degrees of soil degradation

“CLIMATE CHANGE TO DISRUPT SOIL NUTRIENTS IN DRYLANDS”

• Drop in nitrogen and carbon concentrations could have serious effects on ecosystem services.

• Study measured the nitrogen, carbon, and phosphorus content in soils at 224 sites.

“CLIMATE CHANGE TO DISRUPT SOIL NUTRIENTS IN DRYLANDS”

• Drylands consist of 40% of the world’s land area.

• Climate change can make these areas drier.

• It is hypothesized that the ecosystem properties of drylands may be irreversible.