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SOIL POLLUTION Introduction:-soil is one of the most significant ecological factors, which is derived from the transformation of surface rocks. It is nothing but soil on which plants depend for their nutrients,water and minerals supply and anchorage. It constitutes an important medium where in numerous animals live . DEFINATIONS OF SOIL POLLUTION:- It is the unfavourable alteration of soil by addition of removal of substances and factors which decrease soil productivity, quality of plants and ground water is called soil pollution.

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Soil pollution also commonly referred as soil contamination, is defined as a phenomenon characterized by the loss of structural and biological properties by the soil layers as a result of numerous human and natural factors, such as wind, deforestation, chemical use, among others. Soil pollution comprises the pollution of soils with materials, mostly chemicals that are out of place or are present at concentrations higher than normal which may have adverse effects on human or other organisms.


CAUSAL AGENTS SOIL POLLUTION BY NATURAL SOURCES:- Natural and synthetic materials that can adversely affect the physical, chemical and biological properties of soil and seriously affect its productivity are called soil pollutants, and this phenomenon is called as soil pollution. The widespread of industrialization and increasing consumption have changed the very compulsion of soil. Thus the soil is getting heavily polluted day by day by toxic materials and dangerous micro-organisms which enter the air, water and food chain.

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SOIL POLLUTION BY AGROCHEMICALS:- Modern agricultural is one of the important cause for soil pollution. PESTICIDES:- Pesticides legally termed as economic poisons, include insecticides, fungicides, herbicides, rodenticides, nematocides and many other chemicals like disinfectants, antibiotics, defoliants, chemosterilants and juvenile hormones etc… Many toxic pesticides of group organophosphates are active in environment only a few days are week also.

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A major concern particularly about chlorinated hydrocarbons like DDT, Aldrin , Heptachlorine etc…Is their persistance in soil and their movement into water streams through soil erosion and entry into the food chain of various wildlife. FERTILIZERS:- Now a days agricultural practices rely heavily on artificial fertilizers, which generally contain one or more of the plant nutrients i.e nitrogen, phosphorus and potassium.

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SOIL CONDITIONERS, FUMIGANTS AND OTHER CHEMICAL AGENTS:- They contain several toxic metals like lead, arsenic, cadmium, mercury and cobalt etc.. Which when applied to a land will accumulate on soil permanently thereby introducing these chemical components into growing crops. SOLUBLE SALTS:- The United nations Food and Agricultural Organization (FAO) states that half of the irrigated farms in the world are damaged by soluble salts deposited in soil.

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INORGANIC CONTAMINANTS:- The trace elements concentrated in a irregular way are usually metals especially the heavy metals. Some are essential but some are toxic to organisms. They include Hg, Cd , Pb , Ni, Cu, Zn, Mn etc.. MINING:- In surface mining and strip mining man removes top soil and subsoil. This leaves deep salts in the earth the uncontrolled mine fibrous may also destroy the productivity of certain land areas permanently. It leads to loss of grazing and fertile land, soil erosion from waste dumps causes sedimentation or siltation, it is dangerous to aquatic life, damages to flora and fauna as well as water and soil pollution.

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RESISTANT OBJECTS:- Large resistant object such as plastic cans, tyres , polythenes , metalic junk, glasses or even old cars, refrigerators, washing machines etc.. when dumped into nature destroy the beauty of landscape. URBAN WASTES:- It comprises both commercial and domestic wastes consisting of dried sludge of sewage, all the urban solid wastes are commonly referred to as refuge. This refuge contains garbage and rubbish materials like plastic, glasses, metallic cans, fibrous, paper, rubbers, street sweeping, fuel residues, leaves contains abandoned vehicles or other discarded manufactured products.

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BIOLOGICAL AGENTS:- Soil gets large quantity of human animals and birds excretal which constitute the major source of land pollution by biological agents. In addition to these excreta, faulty sanitation, municipal garbage, waste water and wrong methods of agricultural practices also induce heavy soil pollution. RADIOACTIVE POLLUTANTS:- It results from explosion of nuclear devices, atmospheric fallout from nuclear dust and radioactive wastes penetrate the soil and accumulate there creating land pollution. Radiation acutely affect the soil and soil fertility. Radiation kill plant species but differentially variations in radio sensitivity among trees and shrubs are due to differences in chromosome number and size.

Impact on environment:

Impact on environment Soil pollution can lead to water pollution if toxic chemicals leach into groundwater,or if contaminated runoff reaches streams, lakes or oceans. soil also naturally contributes to air pollution by releasing volatile compounds into the atmosphere. Nitrogen escapes trough ammonia volatilization and denitrification . The decomposition of organic materials in soil can release sulfur dioxide and other sulfur compounds, causing acid rain. Heavy metals and other potentially toxic elements are the most serious soil pollutants in sewage. Sewage sludge contains heavy metals and, if applied repeatedly or in large amounts, the treated soil may accumulate heavy metals and consequently become unable to even support plant life.

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In addition, chemicals that are not water soluble contaminate plants that grow on polluted soils, and they also tend to accumulate increasingly toward the top of the food chain. the banning of the pesticides DDT in the united states resulted from its tendency to become more concentrated as it moved from soil to worms or fish, and then to

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