By Cristian Frers
Soil is a natural resource that contains water and nutrients that living beings use. It supports and nourishes the plants in their growth and conditions the entire development of the ecosystem.
Soil is a natural resource that corresponds to the upper layer of the earth's crust. It contains water and nutrients that living things use. The soil is vital, since the human being depends on it for the production of food, the raising of animals, the planting of trees, obtaining water and some mineral resources, among other things. It supports and nourishes plants in their growth and conditions, therefore, the entire development of the ecosystem.
Soil erosion is accelerating on all continents and is degrading some 2 billion hectares of cropland and grazing land, posing a serious threat to the global supply of food. Every year, soil erosion and other forms of land degradation cause the loss of between 5 and 7 million hectares of arable land. In underdeveloped countries, the growing need for food and firewood has resulted in deforestation and cultivation of steep slopes, which has produced severe erosion of the slopes. To further complicate the problem, one must take into account the loss of prime farmland due to industry, swamps, the expansion of cities and roads. Soil erosion and the loss of farmland and forests further reduce the moisture-holding capacity of soils and add sediment to streams, lakes and reservoirs.
The most common problems in relation to the ground have to do with the activities of people. In this regard, the problems directly derived from the anthropic use of soils are currently very severe. Erosion, desertification, pollution, compaction, the advancement of cities and urbanization, and the loss of fertility, are among the most serious problems affecting soils today.
Erosion is the loss of fertile soil, due to the fact that water and wind normally carry the surface layer of the earth to the sea. Human beings accelerate the loss of fertile soils due to the destruction of the vegetation cover, as a result of bad cultivation techniques, overgrazing, burning of vegetation or cutting down the forest. Productive practices without protection criteria, contribute greatly to this problem getting worse every day.
Soil degradation is of great importance, because its regeneration is extremely slow. In tropical and temperate agricultural areas, it takes an average of 500 years to renew 2.5 centimeters of soil.
The cultivation of land in places with slopes increases the possibility of depletion of fertile soil, since it is very easy to carry land away by the action of rain.
The mining activity has used large amounts of firewood, thus eliminating the vegetation cover, essential for the protection of the soil. These practices date back to colonial times, when deforestation wiped out rich forest areas and made them arid.
Erosion can also affect distant ecosystems, such as those of marine life. The soil washed into the sea is deposited as sediment and changes the composition of the seabed, burying vegetation and caves, and transforming the chemical content of the waters.
It is important to note that soil erosion, in addition to affecting and altering ecosystems, seriously affects people and the economy of a place. There is a direct relationship between the decrease in the productive capacity of the soil and the decrease in community income.
Soils have a certain capacity to assimilate human interventions without entering into deterioration processes. However, this capacity has been widely exceeded in many places, as a consequence of the production and accumulation of industrial, mining or urban waste.
Another activity with environmental risk of soil contamination is mining, due to its modifying power of the landscape and its discharges of toxic waste ...
The soil is also contaminated by pesticide residues and other agrochemicals, such as herbicides and fertilizers. Some of them remain in the soil, and from there they are integrated into the food chains, increasing their concentration as they advance through the trophic level.
Soil contamination is also caused by poor disposal and lack of waste treatment. Another serious problem is with industrial waste. The illegal dumping of industrial waste constitutes a serious problem of soil contamination.
Desertification is the intensification of aridity. It should be noted that this term is used to describe processes caused by humans. Instead, another concept called "desertification" is used to describe the natural process of desert formation. Desertification, defined as the intensification of desert conditions and the gradual decrease in the productivity of ecosystems, is generated mainly by human beings, who act on a fragile environment and put excessive pressure on it to obtain their livelihood.
When vegetation is cut down to clear land or use firewood, the fertile layer of the soil is exposed to rain and sun, the crust of the soil hardens and dries, preventing the infiltration of more water. Thus begins the desertification process, since aqueous seepage to underground deposits decreases, and the topsoil layer erodes and becomes sterile.
The main causes of desertification are & shy; rainfed agriculture and irrigation & shy ;, water and wind erosion, climatic changes, overgrazing, deforestation, forest fires, the extinction of native species of flora and fauna, and urban expansion .
Loss of fertility due to monoculture and salinization:
When the same species is planted each year, the land deteriorates. Wheat depletes nitrogen and other nutrients from the soil. If wheat continues to be grown on the same land, production decreases every year. Monoculture of forest species is also a problem for the same reason. It is being seen that replanting pines on the same land is no longer so profitable, because in the second and third plantations the growth rate of the trees decreases. In addition to depleting the land, monoculture multiplies some pests, since they can always count on the type of food to which they are adapted.
Soil salinization is the accumulation of salts from irrigation water and used fertilizers. Due to excess salts, the soil loses its fertility.
Urbanization is the advancement and growth of cities and the building of new populations, which are generally located on fertile soil. In this way, the best agricultural soil is lost, groundwater reservoirs are prevented from recharging, and much microflora and microfauna that live in the soil are destroyed. Much of the soils with high agricultural potential in many countries are within urban limits and the rapid growth of cities threatens the land.
The compaction of the soil is produced by the passage of people, animals and vehicles repeatedly through the same place. This causes the disappearance of the spaces between the soil particles, which reduces the amount of oxygen present and, therefore, the microflora and microfauna ...
Soil degradation is like a silent crisis that is advancing so rapidly in Latin America that few countries have the hope of achieving sustainable agriculture in the near future. It is a problem that, despite threatening the subsistence of millions of people in the region, tends to be ignored by governments and the population in general.
National, provincial and local governments have an urgent responsibility to create greater awareness in the population about the deterioration of land resources and its negative effect on agricultural production and the economy of their countries.
The causes of soil degradation have their origin in socioeconomic factors, in the over-exploitation of the capacity to use the land and in inadequate soil and water management practices.
The available research information on the types, causes, degree, and severity of land degradation is still insufficient in most Latin American countries. This lack of information makes it extremely difficult to identify and implement effective land conservation and rehabilitation strategies.
To overcome the aforementioned problems, solutions that imply immediate action and also prevention methods to prevent further future deterioration should be considered. Part of the damage caused can be solved by nature itself with its natural cycles. For this reason, human action should contribute to creating the necessary conditions for nature to undertake its restoration work. However, recovering the soil once it has been destroyed is a slow process if it is left to its natural rhythm, and very expensive if it is to accelerate it. Therefore, it is most reasonable to avoid destroying the soil. www.EcoPortal.net
* Cristian Frers
Senior Technician in Environmental Management
Superior Technician in Social Communication
Tte. Gral. Juan D. Perón 2049 7th. "55"
(C1040AAE) Autonomous City of Buenos Aires