1. Lesson 8 Soil Use, Abuse, and Conservation

2. Think About It… Why is soil important?

3. Focus Question… Why is it important to preserve and conserve our soil?

4. Natural Resources: An Overview… 1.What are renewable resources? those possible to use indefinitely without causing a reduction in supply Examples include fresh air, fresh surface water, most groundwater, fertile soil, elements that cycle through Earth, all living things

5. Natural Resources: An Overview… 2. What is a nonrenewable resource? exist in a fixed amount and can only be replaced by processes that take thousands of years. Examples include fossil fuels, gemstones, and elements such as gold, copper, and silver. http://library.thinkquest.org/17531/fossil.html

6. Old Growth Trees (Mt. Ranier, Washington) – Nonrenewable!

7. Mariposa Grove of Giant Sequoias, Yosemite, CA

9. Muir Woods NM, CA

10. Conventional Farming… 3. What is conventional agriculture? Standard farming techniques - makes farming easier & grows more food. Includes: –plowing & tilling –pesticides –factory-made fertilizers –monoculture http://www.southernstates.com/catalog http://permaculturenews.org/2011/01/26/why-pasture-cropping-is-such-a-big-deal/

11. http://eartheasy.com/grow_nat_pest_cntrl.htm http://eartheasy.com/grow_nat_pest_cntrl.htm Sustainable Farming… 4. What is sustainable agriculture? Techniques - conserve soil, recycle nutrients, & protect health Includes: no till farming, natural pest control, & natural fertilizers Also called organic farming. Manure-spreading Truck http://www.usawaterquality.org/themes/npm/research/P_Organic.html Beneficial Insect Predator

12. Soil, Agriculture, and Environmental Issues… How long can it take to form just a few inches of soil? 1000 years! Each decade, Earth loses about 7 % of our topsoil. This field in England was left bare and is prone to erosion. http://indianapublicmedia.org/amomentofscience/disappearing-soil/

13. Desertification… 1.Definition - productive land becomes a desert b/c of overgrazing or removing vegetation in dry areas Impact - It turns usable land into a desert 2. Prevention… a.graze cattle wisely b.plant vegetation to retain water See next slide

14. Desertification in the Sahel… http://oceanworld.tamu.edu/resources/environment-book/Images/water-hole-cattle.jpg

15. Monoculture and Biodiversity Loss… 1. Biodiversity is… the number & variety of living things. Ecosystems with a high biodiversity (like rain forests) are healthier & more stable than those with fewer species. http://www.srl.caltech.edu/personnel/krubal/rainforest/Edit560s6/www/animals.html

16. Monoculture… 2. Definition: planting of just one species in a field Used b/c it is easier for farmers 3. Impact: It decreases biodiversity & makes crops more susceptible to disease Sustainable alternative plant several species http://www.bio.davidson.edu/people/kabernd/seminar/2004/Grp4/monoculture.html A Monoculture Field

17. Pesticides 1.Definition: chemicals used to kill pests that eat crops. Used to save crops! 2. Impacts: –kill good insects & decomposers (such as worms). –pollute water & soil –build up in the food chain

18. Moses Cone Manor, NC Pesticides containing lead and arsenic were used in the apple orchards. The soil is still contaminated!

19. Pesticides… Sustainable alternative using carnivorous insects to eat the pests (Like praying mantis and ladybugs)

20. Topsoil Loss: Erosion by Plowing 1.Topsoil is hard to replace b/c… it takes thousands of years to form 2.Plowing causes erosion b/c it clears native vegetation or forests & exposes topsoil Used b/c it is an easy way to clear land 3.Impact: causes a loss of topsoil Things in original soil that can’t be replaced are trace minerals, earthworms, N-fixing bacteria, and humus.

21. Notice the soil loss behind the plow…

22. And this plow in the San Joaquin Valley, CA…

23. Soil Conservation To Reduce soil erosion… No-till farming Terracing Contour farming Windbreaks Gully reclamation See next few slides.

24. Topsoil Loss: Erosion by Plowing 3a. Sustainable alternatives that help conserve topsoil: no-till farming (conservation tillage)

25. Topsoil Loss: Erosion by Plowing 3b. Sustainable alternatives that help conserve topsoil: clover cover http://www.extension.org/pages/31597/overview-of-vineyard-floor-management

26. Reduce Soil Erosion : Terracing (Add to notes.) http://www.acca21.org.cn/image/p3-12.gif

27. Reduce Soil Erosion : Contour farming http://www.ga.nrcs.usda.gov/programs/images/grassedwaterways.jpg

28. Reduce Soil Erosion : Windbreaks http://www.weru.ksu.edu/pics/control/1059.jpg

29. Reduce Soil Erosion : Gully reclamation http:// www.dpi.vic.gov.au/dpi/vro/vroimages.nsf/Images/parwan_vall_gully_head/$File/parwan_valley.jpg

30. Deforestation… 1.Definition: removal of trees without replanting 2.Impacts: loss of soil and clogs waterways with sediment (sedimentation) Sustainable Alternatives: a.selective logging b.buffer zones of trees along streambeds.

31. Deforestation: Selective Logging… The impact of selective logging (taking only some trees from a forest) can be seen in this view of the Tīhoi state forest in 1976. Above the logging road 55% of the timber has been removed, below it only 30% has been removed, while further down is an area of unlogged native forest. Between 1975 and 1984, when selective logging was the only type of harvesting permitted in native forests, the Forest Service carried out trials to see if the damage it caused could be reduced. http://www.teara.govt.nz/en/forestry-research/2/2

32. Urbanization… 1.Definition: People move to cities for jobs and services. 2.Impacts: Natural habitats are lost when forests are cleared & wetlands are filled. a.Construction causes the erosion of topsoil. b.Development takes land away from agricultural use c. Large volumes of solid waste are produced. See next slide…

33. Urbanization – An Extreme Example…Lagos, Nigeria http://mycontinent.co/IMGNigeria/Cities/lagos_traffic.jpg

34. Urbanization… Sustainable Alternates: - Leave some vegetation - Planting greenways - Urban gardens http://morgreen.org/urban-gardens/

35. Properly Designed Landfill… http://your.kingcounty.gov/dnr/kidsweb/images/landfill_diagram.gif