Soil erosion is the loss of soil from land due to the effects of wind and water currents. It is a naturally occurring process - soil always shifts from one location to another - and, under normal conditions, this shifting takes place in a slow and gradual manner. However, under human impact, soil erosion is often drastically accelerated. Some of the issues that hasten the process are deforestation, over grazing and poor or over-zealous farming practices.
Effects of Soil Erosion:
Soil erosion, when it happens very gradually, has minimal effect on the land with enough time for new soil to form. But accelerated erosion is detrimental. Let's look at some of the ill-effects of soil erosion -
- It decreases soil fertility.
- It causes a decrease in crop production and crop quality.
- It can be a safety hazard as the eroding land can lead to accidents and soil that shifts and gets deposited on roads and streets can make driving difficult.
- It can cause environmental damage as loss of soil can make it difficult for natural vegetation to grow in it and thus turn a fertile land into a desert. Another issue is the sediment shifted by water currents and deposited in ponds, which can hurt marine animal and plant life. The soil can cover up fish eggs and prevent their hatching. Or the soil particles stay suspended in water, preventing light from reaching marine plants to allow the photosynthesis process and also retaining heat and raising the water temperature. The soil particles are also abrasive on fish and plant tissue and can kill them off.
- It can lead to financial issues. You need expensive filtration methods to get drinkable water. Soil loss leads to crop failure and more financial loss.
To some extent, it is possible to control soil erosion. The principal thing to do is to maintain a good soil structure. You can do this by planting crops that improve the soil quality, a good example is forage crops. The crop roots hold the soil together and stabilize it against too much loss. Another aspect of having a crop cover is that it blunts the erosive effects of wind and water forces to some extent, as it provides a wind-break, prevents rain from hitting the soil surface directly and catches runoff water.
Run-off water is also caught by mulching - that is, covering the soil with organic matter like crop residues (stalks, stems and leaves), straw, grass and fallen leaves. Mulched rip lines stop run-off water inside the fields. Continual addition of organic matter enriches the soil and also helps it retain its moisture during hot and dry summers. Adding manures (cow manure is the best)and following proper tillage practices also goes a long way in helping control soil erosion. Man-made terraces and Contour plowing (plowing along the land contour) are two examples. Some farmers prefer to go for mixed cropping and strip cropping, which involves planting forage crops in alternating strips with regular crops. Early planting, before the start of the Monsoon season, can prevent soil erosion as there will already be a burgeoning crop cover by the time the rains start. Planting tall trees along the land borders work as an effective wind-break and planting the trees among the crops works equally well.
Other erosion preventive measures include having grassed waterways to deliver water to fields, installing cut-off drains and contour drains that follow field boundaries and stop run-on water from flowing into the crop fields, and putting up sand bag and gravel bag barriers. You can also create effective barriers with man-made coir logs and rolls, which are both eco-friendly and effective.
Benefits of controlling soil erosion -
The benefits of controlling erosion are, of course, manifold. Less erosion means the better soil quality, with the soil retaining the nutrients and chemicals added to it, and this naturally leads to better and more improved crop yields. Erosion control can reduce the expenses involved in drainage and in water filtration. And better yet, it can counter and help redress any long-term damage to the environment.