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i need points on soil erosion due to human activity!!✌✌✌
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The way people use land can affect the levels of nutrients and pollution in soil. ... However, farming has some harmful effects and canlead to soil loss. Farmers often add nutrients to soil in the form of organic or artificial fertilizers to make their crops grow better.
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Soil is a non-renewable resource that once it is eroded it is not renewed. Soil erosion is the permanent change of the main characteristics of soil that could see it lose its fertility, pH, colour, humus content or structure. Soil erosion occurs naturally by wind or harsh climatic conditions but human activities include overgrazing, overcropping and deforestation.
Overcropping is when the land is being continuously under cultivation and is not allowed to lie fallow between crops. This constant farming of the land reduces the soils ability to produce valuable humus for soil fertility as it is constantly being ploughed or stripped for crop growth. The soil becomes drier and less fertile. While humus is primarily needed for the addition of nutrients and minerals it is also a valuable source of air and water needed by soil to keep it moist and aerated. With less humus the soil dries out and is open for wind and rain erosion. Usually over cropping occurs in areas where there is a demand for crops either for market or a large local population. Many farmers attempt to restore soil fertility by adding fertilizers or artificial nutrients but some countries do not have this opportunity due to poverty or lack of education. In South America soya is a quick-growing and valuable crop. The leading producers of soya in this region are Brazil and Argentina. Despite some artificial fertilisers being added the soil is not allowed enough time to recover its fertility or structure and is ultimately being eroded by this human activity.
Deforestation is the cutting down of large areas of forests leaving an open, exposed landscape. Deforestation occurs for many reasons such as the sale of wood, charcoal or as a source of fuel, while cleared land is used as pasturefor livestock, plantations of commodities, and settlements. The removal of trees without sufficient reforestation has resulted in damage to habitat, biodiversity loss and aridity (drying of soil). This human activity quickly accelerates natural erosion in two ways. Firstly the removal of trees is a removal of nutrients and minerals from the soil as the source of humus is greatly reduced. The natural dead organic material that supplies the soil with its humus is generally leaves that have fallen from the trees, animal droppings, tree fruit or decaying trees in the soil. Secondly, deforestation accelerates soil erosion by leaving large areas exposed to heavy rainfall (which can cause leaching or flash floods) or wind erosion. Without the roots of the trees to keep the soil structure in place the soil is loose and easier to erode. The tropical rainforests of Brazil are seeing huge areas of forest being cut down each day. Each year about 13 million hectares of the world’s forests are lost due to deforestation.
Farming techniques such as contour ploughing, stubble planting and time of ploughing can also be useful methods of soil conservation. Contour ploughing is the ploughing of the land following the natural contours of the land instead of the usual practice of going up and down the slopes in lines. If farmers follow the natural contours it can reduce the amount of soil creep or mass movement along the slope as the soil is not destabilised and more vulnerable to erosion. The grooves between ploughed lines allows rainwater to find its way naturally downslope again reducing the possibility of valuable top soil being carried downhill. Stubble planting is something that is practiced in Ireland in areas where grains and cereal crops are produced. As the wheat or barley is harvested by the combine harvester it leaves short stubble of stalks left in the ground. Over time these stubbles decompose becoming valuable humus. The stubble also act as anchors to keep the soil in place until the next crop is planted. Then when the next crop is being planted a technique known as ‘slitting’ is used. This is where small slits are cut into the soil for seeding for the next batch of crops. By not reploughing the soil the structure is maintained and the possibility of erosion is reduced or removed. Finally farmers have changed their planting times to reduce the possibility of soil erosion. This now takes place in wetter conditions when the soil is not likely to become windborne in warm, dry conditions.
Overcropping is when the land is being continuously under cultivation and is not allowed to lie fallow between crops. This constant farming of the land reduces the soils ability to produce valuable humus for soil fertility as it is constantly being ploughed or stripped for crop growth. The soil becomes drier and less fertile. While humus is primarily needed for the addition of nutrients and minerals it is also a valuable source of air and water needed by soil to keep it moist and aerated. With less humus the soil dries out and is open for wind and rain erosion. Usually over cropping occurs in areas where there is a demand for crops either for market or a large local population. Many farmers attempt to restore soil fertility by adding fertilizers or artificial nutrients but some countries do not have this opportunity due to poverty or lack of education. In South America soya is a quick-growing and valuable crop. The leading producers of soya in this region are Brazil and Argentina. Despite some artificial fertilisers being added the soil is not allowed enough time to recover its fertility or structure and is ultimately being eroded by this human activity.
Deforestation is the cutting down of large areas of forests leaving an open, exposed landscape. Deforestation occurs for many reasons such as the sale of wood, charcoal or as a source of fuel, while cleared land is used as pasturefor livestock, plantations of commodities, and settlements. The removal of trees without sufficient reforestation has resulted in damage to habitat, biodiversity loss and aridity (drying of soil). This human activity quickly accelerates natural erosion in two ways. Firstly the removal of trees is a removal of nutrients and minerals from the soil as the source of humus is greatly reduced. The natural dead organic material that supplies the soil with its humus is generally leaves that have fallen from the trees, animal droppings, tree fruit or decaying trees in the soil. Secondly, deforestation accelerates soil erosion by leaving large areas exposed to heavy rainfall (which can cause leaching or flash floods) or wind erosion. Without the roots of the trees to keep the soil structure in place the soil is loose and easier to erode. The tropical rainforests of Brazil are seeing huge areas of forest being cut down each day. Each year about 13 million hectares of the world’s forests are lost due to deforestation.
Farming techniques such as contour ploughing, stubble planting and time of ploughing can also be useful methods of soil conservation. Contour ploughing is the ploughing of the land following the natural contours of the land instead of the usual practice of going up and down the slopes in lines. If farmers follow the natural contours it can reduce the amount of soil creep or mass movement along the slope as the soil is not destabilised and more vulnerable to erosion. The grooves between ploughed lines allows rainwater to find its way naturally downslope again reducing the possibility of valuable top soil being carried downhill. Stubble planting is something that is practiced in Ireland in areas where grains and cereal crops are produced. As the wheat or barley is harvested by the combine harvester it leaves short stubble of stalks left in the ground. Over time these stubbles decompose becoming valuable humus. The stubble also act as anchors to keep the soil in place until the next crop is planted. Then when the next crop is being planted a technique known as ‘slitting’ is used. This is where small slits are cut into the soil for seeding for the next batch of crops. By not reploughing the soil the structure is maintained and the possibility of erosion is reduced or removed. Finally farmers have changed their planting times to reduce the possibility of soil erosion. This now takes place in wetter conditions when the soil is not likely to become windborne in warm, dry conditions.
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