1. UNIT #2 Soil What is soil?

2. Soil: A mixture of mineral particles and organic material that covers the land, and in which terrestrial plants grow.

3. Other Definitions… See textbook.

5. Permeability and Porosity

7. Why Degradation? Human activities such as overgrazing, deforestation, unsustainable agriculture and irrigation cause processes of degradation. These include soil erosion, toxification and salinization. Desertification (enlargement of deserts through human activities) can be associated with this degradation.

24. Soil Conservation soil conditioners (for example, use of lime and organic materials) wind reduction techniques (wind breaks, shelter belts, strip cultivation) cultivation techniques (terracing, contour plowing) efforts to stop plowing of marginal lands.

32. LEDC vs MEDC

34. Sources Visited http://www.eslarp.uiuc.edu/la/LA437-F94/soils/texture.gif http://www.atmos.albany.edu/deas/atmclasses/atm301/soil_xsec.jpg http://www3.gov.ab.ca/env/water/GWSW/quantity/learn/Evaluation/EV_Images/EV3_porosity.gif http://academic.emporia.edu/aberjame/wetland/define/soil01.jpg http://sgp.undp.org/intranet//img/projects/7167/img_VN-03-002-2.JPG http://upload.wikimedia.org/wikipedia/commons/a/a8/No_till_farming_SemisDirect_USDA.jpg http://www.fairfaxcounty.gov/nvswcd/images/notill2.jpg Thomson Higher Education http://www.uwsp.edu/stuorg/swcs/swcs_soil.jpg http://i.pbase.com/g6/07/66107/2/85212459.PByXZTQC.jpg http://static.panoramio.com/photos/original/23089205.jpg http://inlinethumb45.webshots.com/26732/2664528040104237032S600x600Q85.jpg