Soil Erosion Soil
SOIL
Soil is formed at a rate of only 1 cm every 100 to 400 years and it takes 3000 to 12000 years to build enough soil to form productive land. This means that soil is a nonrenewable resource and once destroyed it is gone forever.
If we disregard this, a time will come when there would not be enough soil left to sustain life on earth, because the soil is a necessary growth medium for plants, a home for certain insects and animals, as well as a medium from which we get minerals, such as gold. It is important therefore to treat soil, especially topsoil, as a living entity.
SOIL EROSION
Soil erosion is when the soil is blown away by the wind or washed away by the rain.
Soil erosion is common in areas with steep slopes, where trees have been cut down, in droughts when crops and other vegetation grow poorly and in rural areas which are overpopulated. Nepal, in the Himalayan Mountains, has severe problems caused by increased population density and steep slopes.
Soil erosion can be reduced by building terraces on hillsides, irrigation schemes to overcome droughts, planting more trees to bind the soil together and make wind breaks, and using fertilizers in overpopulated areas to make the soil more fertile. It is very important that the farming techniques used do not damage the structure of the soil, as this makes it easily eroded. Good farming techniques include contour ploughing, crop rotation and keeping the soil rich in humus.
An example of poor techniques was the "Dust Bowl" in the mid-western states of the U.S.A. in the 1930's. Farmers exhausted the soil by monoculture and left the soil bare after harvesting. Soil erosion is a problem of the developed world as well as the developing
TYPES OF SOIL EROSION
Water erosion
Water erosion causes two sets of problems: * An on-site loss of agricultural potential * An off-site effect of downstream movement of sediment, causing flooding and the silting up of reservoirs.
Sheet erosion * Soil erosion is
Soil is formed at a rate of only 1 cm every 100 to 400 years and it takes 3000 to 12000 years to build enough soil to form productive land. This means that soil is a nonrenewable resource and once destroyed it is gone forever.
If we disregard this, a time will come when there would not be enough soil left to sustain life on earth, because the soil is a necessary growth medium for plants, a home for certain insects and animals, as well as a medium from which we get minerals, such as gold. It is important therefore to treat soil, especially topsoil, as a living entity.
SOIL EROSION
Soil erosion is when the soil is blown away by the wind or washed away by the rain.
Soil erosion is common in areas with steep slopes, where trees have been cut down, in droughts when crops and other vegetation grow poorly and in rural areas which are overpopulated. Nepal, in the Himalayan Mountains, has severe problems caused by increased population density and steep slopes.
Soil erosion can be reduced by building terraces on hillsides, irrigation schemes to overcome droughts, planting more trees to bind the soil together and make wind breaks, and using fertilizers in overpopulated areas to make the soil more fertile. It is very important that the farming techniques used do not damage the structure of the soil, as this makes it easily eroded. Good farming techniques include contour ploughing, crop rotation and keeping the soil rich in humus.
An example of poor techniques was the "Dust Bowl" in the mid-western states of the U.S.A. in the 1930's. Farmers exhausted the soil by monoculture and left the soil bare after harvesting. Soil erosion is a problem of the developed world as well as the developing
TYPES OF SOIL EROSION
Water erosion
Water erosion causes two sets of problems: * An on-site loss of agricultural potential * An off-site effect of downstream movement of sediment, causing flooding and the silting up of reservoirs.
Sheet erosion * Soil erosion is