October 12, 2011

October 12, 2011

Objective: By using a soil map

determine areas of good fertility.

Agenda:Go over soil TriangleSoil Map of N.C.

Page 372 answer questions 1-6

Soil conservation notesErosion of Topsoil

activityHomework:Page368-369 answer

questions 1-13 , write out answers only!

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 Erosion

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.

Soil Conservation Practices