This is because the higher demand for food and fuel causes the removal of protective vegetation from the area, meaning that rain-splash erosion and aeolian erosion can occur. The chance of desertification increases when an area is experiencing drought conditions. This is because the soil is already stressed by the processes of overcropping and overgrazing, and so a drought dries out the soil completely and causes it to become useless and desertified. In Sahelian countries such as Chad and Niger, cash crops (Crops only sold for their monetary value) such as cotton and cashew nuts are grown in massive plantations as part of economic reforms known as structural adhustment programmes. This is because the owners of these farms receive debt relief for growing this crop.
This can effect crop production which is essential due to the growing population of the world. Over population often puts pressure on a country to produce more. This leads to poor farming practices, overgrazing and monoculture. The constant land degradation and low rainfall causes desertification in arid and semi-arid areas. The desertification results in unproductive farmland which increases the pressure to produce food even more.
Often, desertification is the result of a number of causes or is provoked by one cause and intensified by others (Darkoh, 1996). Concrete analysis of an environmental situation and of the factors involved will make it possible to find national and international means to prevent and control desertification and ways of restoring the biological potential of the area. Both desertification prevention and control often require a combination of social, economic and technologically coordinated activities, constituting an overall plan of social and economic development for a particular territory. 1.4 Need to Control Desertification Desertification causes great human misery, starvation or malnutrition. Its symptoms are as follows (Sheridan, 1981): i) Degradation of native vegetation due to natural or manmade actions.
Such practices have a negative effect on proper management of natural forest resources and ultimately the land is easily degraded (Asefa 1994). These factors adversely affected natural resources; particularly native forests Deforestation continues to cause environmental degradation in the form of land and water resources degradation as well as loss of native tree species. 2.4 Major Cause of Deforestation Deforestation is caused by what human beings do to the forests and can be accentuated by drought. Generally deforestation occurs when people clear forest for their personal need such as, for fuel, hunting, when they need the land to grow and harvest crops, for building houses, and at times because of religion beliefs (Sucoff, 2003).
In order to be able to feed its population, the country will need to have a minimum cultivated land are of 107 million ha. Acknowledging the great challenge, the government stopped land reclamation in its vast west and reconverted 7.86 million ha of cultivated lead to ecological purposes. Even so, China had still an annual loss of grain production of around 6.5 million tons. In order to get better results, the Chinese government urged the introduction of stricter regulation which, in effect, closed 4735 development zones covering a total planned area of 2.4 million ha. Since then, approval of any proposal for development zones has been suspended.
The root cause of desertification is poor soil conservation leading to soil degradation. Unsustainable farming methods also contribute to soil degradation. Overuse of chemical fertilizers, failure to employ crop rotation and irresponsible irrigation practices rob the soil of the last of its nutrients. When topsoil is depleted of humus, it 's either too loose or too compacted, both of which can lead to destructive erosion. In a White Paper by the United Nations Convention to Combat Desertification it is pointed out that the economic impact to land degradation have ranged from “2% of Gross Domestic Product in India to 0.04% of GDP in the USA.” Social impacts are determined by the number of people living in the affected areas and their economic status.
Many of the scientists agree with that the period of agricultural revolution has been occurring during 18th and early 19th centuries in Europe as a result of technological improvement and increased crop productivity. During the industrial revolution much more land had been taken under the plough to produce a greater agricultural production such as wheat and livestock forcing the ability of soils by means of several mechanization tools. Total land area of the world is about 13.5 billion hectares and only 22% (3.03 billion hectares) of that is actually cultivable and about 66% (2 billion hectares) is degraded. The soil loss was expected to go up to 10 million hectares annually by 2000 A.D. (Yadav, 1996). In India alone, almost 57% of total land area (about 188 million hectares) is degraded (Sehgal and Abroll, 1994).
Deforestation leads to soil erosion and an increased frequency of floods and droughts. When trees are removed, there will be lesser tree roots to hold onto the soil and lesser rain will be intercepted by the different forest layers before hitting the ground. As estimated 62 percent
due to the over population, the number of various chemical elements in increasing in the atmosphere which ultimately causes irregular rainfall and global warming. It is very true that climate changes goes slowly, however continuous slow process is very dangerous. because regular changes in the environment physical structures of the human beings and other living species has been changed from generation to generation. Increasing human population needs more land for agricultural cultivation and living purpose which force them to cut more trees and forests so the deforestation has its own dangerous side effects. I believe everyone present can agree that all of these issues exist and that humans have caused them.
Particularly in developing countries, a major problem with farming techniques is that they can lead to soil erosion and the degradation of soil quality and fertility from overuse, acidification, salinsation and other chemical contamination. Certain crops, the livelihood of large parts of developing countries – coffee, corn, rice, wheat and tobacco, cause more soil erosion than others. Although these crops are essential to the local community and economy, for farming practices to be sustainable, farmers must be persuaded to modify their practices and apply soil conservation techniques. Which are the (relevant) practices that have an impact on the respective environmental problem? When farmland is ploughed, topsoil is exposed and may be blown away by the wind or washed away by rain.