Soil Lab & Rangelands
Soil lab, Rangelands, Case Study
AP ? Of the Day
Deforestation, overgrazing, and the overworking of soil for crop production
can lead to which of the following?
A.
B.
C.
D.
E.
Salinization
Monoculture
Desertification
Increased crop rotation
Depletion of aquifers
AP ? Of the Day
Deforestation, overgrazing, and the overworking of soil for crop production
can lead to which of the following?
C. Desertification
Desertification is the loss of soil productivity due to erosion,
overgrazing, drought, soil compaction (tilling!), and any other factors
that deplete the soil (like lack of crop rotation).
(Overgrazing is the number 1 contributor to desertification.)
Reminders…
• Chapter reading guides are due 1/20 and 1/21
• Test is 1/20 and 1/21
• Check the website for a hint on your FRQ!
Today…
• Rangelands mini-lecture
• Soils & soil lab
• Case Study on rangelands & soils
Rangelands
• Supply forage or vegetation for grazing and browsing animals, but are NOT
managed.
• Include: prairies, desert scrub, grasslands, chaparral (shrublands), open
woodlands, riparian (areas alongside streams and rivers), and arctic tundra.
Rangelands & Livestock
• 40% of rangelands, worldwide, are devoted to livestock
• About 25% of the US is rangeland (though grazing does take place legally on
public land)
Rangelands - Threats
• Major environmental problem: overgrazing  soil compaction, soil erosion,
desertification & loss of biodiversity
Rangelands in the News…
• Link
Managing Rangelands
• Continuous grazing – most common in the US, less costly.
vs.
• Deferred grazing – moving livestock between two or more grazing areas, giving the grasses
time to recover. Better at protecting quality of the land.
Other methods of rangeland management:
1. Issuing permits to limit the number of ranchers that can use public land
2. Reducing the # of livestock on the land
3. Use fences and streams to presever habitats
4. Prevent grazing on poorly conditioned land until it can recover
I Could Tell You About Soil…. But,
• Link
• Wouldn’t you rather
Lorde tell you about it?
Soil Lab – 30 minutes
• If you set up your soil column at least 24 hours ago, you can proceed with
Soil Lab Day 2.
• If you have not, set up your column and then move to part III. You can
complete this portion during this class period.
• If you do not complete the soil column and pH portion today, you will need
to complete the second portion by arranging a time with me.
After your lab…
• Pick up a Case Study (From Prairies to Corn Fields…)
• You will need to complete this as a team for a grade. Take turns writing the
answers!
• I will give you 15 minutes next class to finish if needed.