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October 12, 2011. Objective: By using a soil map determine areas of good fertility. Agenda: Go over soil Triangle Soil Map of N.C. Page 372 answer questions 1-6 Soil conservation notes Erosion of Topsoil activity Homework: Page368-369 answer questions 1-13 , write out answers only!.
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Objective: • By using a soil map determine areas of good fertility. Agenda: • Go over soil Triangle • Soil Map of N.C. • Page 372 answer questions 1-6 • Soil conservation notes • Erosion of Topsoil activity • Homework: • Page368-369 answer questions 1-13 , write out answers only!
Soil Erosion • Erosion- Transportation of soil by wind, water, or ice. • Worldwide removes 25.4 Billion tons/yr. • Made worse by deforestation and desertification. • Poor agricultural practices increase erosion and lead to the transport of associated fertilizers and pesticides.
Soil Erosion • Most current agricultural areas lose topsoil faster than it can be replenished. • Wind erosion may not be as evident as water erosion, but is still common. • Most common in dry, treeless areas. • Great Plains have had four serious bouts of wind erosion since late 1800’s.
Soil Conservation Practices • When topsoil is lost, fertility is reduced or destroyed, thus fertilizers must be used to restore fertility. • Raises food costs, and increases sediment loads in waterways. • Over 20% of US land is suitable for agriculture, but only 2% does not require some form of soil conservation practice.
Soil Conservation Practices • Contour Farming - Tilling at right angles to the slope of the land. Each ridge acts as a small dam.
Soil Conservation Practices • Strip Farming - Alternating strips of closely sown crops to slow water flow.
Soil Conservation Practices • Terracing - Level areas constructed at right angles to the slope to retain water - good for very steep land.
Soil Conservation Practices • Waterways - Depressions in sloping land where water collects and flows off the land.
Soil Conservation Practices • Windbreaks - Planting of trees or other plants that protect bare soil from full force of the wind.