1. Land Use

2. DQ: 10/23
Name and Describe three ways that humans use land.

3. How We Use Land Land Use is measured by: Maps Aerial Photos
Field Surveys
Computerized mapping system

4. Land Use
Measurements taken in California showed that in 8 years ( ) nearly 210,000 acres of farmland, rangeland and woodland had been converted into suburbs and cities.
Issue:
How will we feed the exponential growing population?

5. Land Us in the United States
357 million acres of cropland
406 million acre of forestland
19 million acres of pastureland
409 million acres of rangeland

6. Major Concerns Major land use natural resource concerns include:
erosion by wind and water
maintaining and enhancing soil quality
water quality and quantity
plant condition and health
wildlife habitat

7. Land Use and Land Cover Urban area: Rural area:
Covered by mainly buildings and roads and defined as an area that contains 2,500 or more people.
Rural area:
Those areas that have relatively less people and more open space.

8. Agriculture: How to Feed a Growing Population
Clearing land for increased agriculture
Food and Agriculture Organization of the United Nations reported that the number of undernourished people in LDCs increased to over 826 million
357 million acres of cropland is threatened by urban development.
North Carolina
Twin Cities

9. Cropland Threatened Since its creation:
In 1996, the U.S. government established the Farmland Protection Program:
Helps protect farmland in danger of being paved over or otherwise developed.
Gives financial assistances to help
keep land in agriculture
Since its creation:
885 million
Purchased 3,993 farms

10. Types of Agriculture Conventional, or unsustainable agriculture
Agroecology, or sustainable agriculture
With a partner fill in the table:

11. Susceptible to soil erosion
Type
Conventional
Sustainable
Altering Land
Number of crops/field
Harvest
After Harvest
Susceptible to soil erosion
Herbicide Use
Pesticide Use
Fertilizer Use
Altering Land: Do they change the land? If so, how? (till, irrigate)
Crops/field: How many different crops per field?
Harvest: How often? At the same time?
After Harvest: What happens to the land after harvest? (Bare or not bare)

12. Conventional agriculture disrupts natural ecology of the field
Land get stripped for planting displacing herbivores without natural vegetation.
Chemical fertilizers, herbicides and pesticides leach into the solid and groundwater
Phosphates stimulate algal blooms in local streams and water sources.
Single crops tend to deplete the soil of vital nutrients.
Bare fields after harvesting are susceptible to soil erosion by wind and rain.
Use of seeds, fertilizer, herbicides and pesticides are expensive.

13. Green Revolution
Began in the 1940s as a way to help farmers in India and Mexico increase their productivity and relieve hunger.
Developed by a plant scientist: Norman Borlaug
Produced high-yield varieties of wheat that were more resistant to pests and disease.
In the 1960s they developed new high-yield versions of rice, corn and beans
Process called genetic engineering

14. Green Revolution Farmers could plant and harvest crops more quickly
Helped relieve famine in Latin America and Asia
However, not successful in all areas because of climate and irrigation techniques not available.
Sub-Saharan Africa

15. Irrigation One major factor in the Green Revolution
Uses about 60 percent of the world’s freshwater supplies.
Different techniques:
Flood or Furrow Irrigation
Drip Irrigation
Spray Irrigation

16. Rangeland
Areas of land that supply forage or vegetation for grazing and browsing animals but are not managed.
Land includes:
Prairies
Desert scrub
Grasslands
Chaparral (shrublands)
Arctic tundra/desert
Open woodlands

17. Rangeland Worldwide 40% devoted to livestock
About 25% of the US is rangelands
Areas of low to moderate rainfall (arid, semi-arid)

18. Environmental Problem
Overgrazing:
Occurs when too many animals graze for too long on a given area, exceeding the carrying capacity of the rangeland
Removes vegetation and compacts soil so it not longer holds water
Increased soil erosion and loss of biodiversity