22.
Causes Of Land Degeneration
According to a new report published by the United Nations Food and Agriculture Organization, the livestock sector is a major source of land and water degradation.
Says Henning Steinfeld, Chief of FAO’s Livestock Information and Policy Branch and senior author of the report: “Livestock are one of the most significant contributors to today’s most serious environmental problems. Urgent action is required to remedy the situation.”
United Nations scientists, in their 408-page indictment of the meat industry, point out that the meat industry is “one of the most significant contributors to the most serious environmental problems, at every scale from local to global,” including “problems of land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity.”
Meat in our diets takes its toll on Earth’s surface in two main ways: over-grazing and use of land to grow feed for animals. As demand for animal products rise, demand on the lands that support grazing or feed production becomes overwhelming (that is, unsustainable).
Lester Brown, the founder of the Worldwatch Institute, calculated that the needs of 230 million cattle, 246 million sheep and 175 million goats grazing on the African continent exceed the lands’ capacity by at least half. In Africa, if current trends of soil degradation continue, the continent might be able to feed just 25% of its population by 2025, according to UNU’s Ghana-based Institute for Natural Resources in Africa.
Clearing land to graze animals or to grow animal feed leads to erosion, food shortages (as land to grow other crops is reduced, and eventually left barren), and global warming (from loss of plant life that would otherwise absorb CO2). ‘’Overgrazing of rangelands,” notes Brown, “initially reduces their productivity but eventually it destroys them, leaving desert.” Enter the term “desertification”: the process whereby fertile and stable lands become — you got it — deserts. We lose billions of tons of topsoil every year to rising demands for meat and irresponsible growing and grazing practices — a rate that, putting it lightly, far outpaces the 100 to 500 years it takes to produce one inch of topsoil. (Industrial farming loses up to six inches of topsoil a year.)
Says Henning Steinfeld, Chief of FAO’s Livestock Information and Policy Branch and senior author of the report: “Livestock are one of the most significant contributors to today’s most serious environmental problems. Urgent action is required to remedy the situation.”
United Nations scientists, in their 408-page indictment of the meat industry, point out that the meat industry is “one of the most significant contributors to the most serious environmental problems, at every scale from local to global,” including “problems of land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity.”
Meat in our diets takes its toll on Earth’s surface in two main ways: over-grazing and use of land to grow feed for animals. As demand for animal products rise, demand on the lands that support grazing or feed production becomes overwhelming (that is, unsustainable).
Lester Brown, the founder of the Worldwatch Institute, calculated that the needs of 230 million cattle, 246 million sheep and 175 million goats grazing on the African continent exceed the lands’ capacity by at least half. In Africa, if current trends of soil degradation continue, the continent might be able to feed just 25% of its population by 2025, according to UNU’s Ghana-based Institute for Natural Resources in Africa.
Clearing land to graze animals or to grow animal feed leads to erosion, food shortages (as land to grow other crops is reduced, and eventually left barren), and global warming (from loss of plant life that would otherwise absorb CO2). ‘’Overgrazing of rangelands,” notes Brown, “initially reduces their productivity but eventually it destroys them, leaving desert.” Enter the term “desertification”: the process whereby fertile and stable lands become — you got it — deserts. We lose billions of tons of topsoil every year to rising demands for meat and irresponsible growing and grazing practices — a rate that, putting it lightly, far outpaces the 100 to 500 years it takes to produce one inch of topsoil. (Industrial farming loses up to six inches of topsoil a year.)
Deforestation
In an undisturbed forest, the mineral soil is protected by a layer of leaf litter and an humus that cover the forest floor. These two layers form a protective mat over the soil that absorbs the impact of rain drops. They are porous and highly permeable to rainfall, and allow rainwater to slow percolate into the soil below, instead of flowing over the surface as runoff. The roots of the trees and plants hold together soil particles, preventing them from being washed away. The vegetative cover acts to reduce the velocity of the raindrops that strike the foliage and stems before hitting the ground, reducing their kinetic energy. However it is the forest floor, more than the canopy, that prevents surface erosion. The terminal velocity of rain drops is reached in about 8 meters. Because forest canopies are usually higher than this, rain drops can often regain terminal velocity even after striking the canopy. However, the intact
forest floor, with its layers of leaf litter and organic matter, is still able to absorb the impact of the rainfall.
Deforestation causes increased erosion rates due to exposure of mineral soil by removing the humus and litter layers from the soil surface, removing the vegetative cover that binds soil together, and causing heavy soil compaction from logging equipment. Once trees have been removed by fire or logging, infiltration rates become high and erosion low to the degree the forest floor remains intact.
Globally, we are using more and more land to make room for more and more animals and the crops needed to feed them. An estimated 30 percent of the earth’s ice-free land is involved in livestock production, according to the U.N.’s Food and Agriculture Organization. Forests are a precious means of maintaining soil health and climate stability, but rain forests (Brazil) and ancient pine forests (China) — entire ecosystems worldwide — are being destroyed to feed the animals that feed us. The expanding use of land for grazing and growing animal feed crops is now a dominant reason for deforestation in most countries. Much of the prairies in central Canada have been lost.
Deforestation contributes to global warming, topsoil depletion, drought, plant and animal extinction, and loss of biodiversity. Basically, we are devouring trees to make way for an ever-increasing number of farmed animals. These animals, in turn, devour vast amounts of energy, natural resources and food calories, so that we can, in turn, devour their meat.
To give you some sense of the vast tracts of land needed to graze or otherwise feed the animals that feed us, scientists at the Smithsonian Institute figure that the equivalent of seven football fields of land is bulldozed every minute. Every minute. According to the U.S. General Accounting Office, more plant species are threatened or annihilated by livestock grazing than by any other cause.
In India not much forest cover remains. Tropical forest cover in India has been reduced to two major areas: the coastal hills of the Western Ghats (about 135,000 sq. km) and 34,500 sq. km in Northeastern India. Very little of India’s forest cover is considered pristine. According to Forest Survey of India, the country has lost an alarming 3,762,000 ha of forest since 1990. That is 5.9% of the total forest area. At this rate, the country may become bald in next few decades.
forest floor, with its layers of leaf litter and organic matter, is still able to absorb the impact of the rainfall.
Deforestation causes increased erosion rates due to exposure of mineral soil by removing the humus and litter layers from the soil surface, removing the vegetative cover that binds soil together, and causing heavy soil compaction from logging equipment. Once trees have been removed by fire or logging, infiltration rates become high and erosion low to the degree the forest floor remains intact.
Globally, we are using more and more land to make room for more and more animals and the crops needed to feed them. An estimated 30 percent of the earth’s ice-free land is involved in livestock production, according to the U.N.’s Food and Agriculture Organization. Forests are a precious means of maintaining soil health and climate stability, but rain forests (Brazil) and ancient pine forests (China) — entire ecosystems worldwide — are being destroyed to feed the animals that feed us. The expanding use of land for grazing and growing animal feed crops is now a dominant reason for deforestation in most countries. Much of the prairies in central Canada have been lost.
Deforestation contributes to global warming, topsoil depletion, drought, plant and animal extinction, and loss of biodiversity. Basically, we are devouring trees to make way for an ever-increasing number of farmed animals. These animals, in turn, devour vast amounts of energy, natural resources and food calories, so that we can, in turn, devour their meat.
To give you some sense of the vast tracts of land needed to graze or otherwise feed the animals that feed us, scientists at the Smithsonian Institute figure that the equivalent of seven football fields of land is bulldozed every minute. Every minute. According to the U.S. General Accounting Office, more plant species are threatened or annihilated by livestock grazing than by any other cause.
In India not much forest cover remains. Tropical forest cover in India has been reduced to two major areas: the coastal hills of the Western Ghats (about 135,000 sq. km) and 34,500 sq. km in Northeastern India. Very little of India’s forest cover is considered pristine. According to Forest Survey of India, the country has lost an alarming 3,762,000 ha of forest since 1990. That is 5.9% of the total forest area. At this rate, the country may become bald in next few decades.
Wind Erosion
Wind erosion in the study of geology and weather, pertain to wind activity and specifically to the wind’s ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation. Although water is a much more powerful eroding force than wind, wind erosion processes are more visible in arid environments such as deserts.
This type of erosion basically involves displacement of soil particles by the action of wind. Normally the soil is removed in thin layers as sheet erosion, but sometimes wind effect can carve out hollows and other features. Wind erosion is a function of wind velocity, soil characteristics and land use. Wind displaces fine to medium size sand particles.
Soil erosion due to growing livestock feed is estimated to be 40 billion tons per year (or 6 tons/year for every human being on the planet). About 60% of soil that is washed away ends up in rivers, streams and lakes, making waterways more prone to flooding and to contamination from soil’s fertilizers and pesticides. Erosion increases the amount of dust carried by wind, polluting the air and carrying infection and disease.
In India the land degradation due to wind erosion is limited to arid regions. Experimental studies on wind erosion under different land uses were conducted by the Central Arid Zone Research Institute (CAZRI), Jodhpur, and different parameters have been standardized for wind erosion.
An area of 11 Million hectares is found suffering from wind erosion of various intensities. Very severe and severe wind erosion occur in 16% of the total geographical area (TGA) of the country. Moderate wind erosion occurs in 32% of TGA.
Wind erosion is more prominent in the hot arid region occupying 31.7 million hectares. Removal of vegetative cover and overgrazing enhance the intensity and extent of wind erosion and desertification. The sand movement causes calcine damage to the adjoining cultivated areas, roads, canals, buildings, etc.
This type of erosion basically involves displacement of soil particles by the action of wind. Normally the soil is removed in thin layers as sheet erosion, but sometimes wind effect can carve out hollows and other features. Wind erosion is a function of wind velocity, soil characteristics and land use. Wind displaces fine to medium size sand particles.
Soil erosion due to growing livestock feed is estimated to be 40 billion tons per year (or 6 tons/year for every human being on the planet). About 60% of soil that is washed away ends up in rivers, streams and lakes, making waterways more prone to flooding and to contamination from soil’s fertilizers and pesticides. Erosion increases the amount of dust carried by wind, polluting the air and carrying infection and disease.
In India the land degradation due to wind erosion is limited to arid regions. Experimental studies on wind erosion under different land uses were conducted by the Central Arid Zone Research Institute (CAZRI), Jodhpur, and different parameters have been standardized for wind erosion.
An area of 11 Million hectares is found suffering from wind erosion of various intensities. Very severe and severe wind erosion occur in 16% of the total geographical area (TGA) of the country. Moderate wind erosion occurs in 32% of TGA.
Wind erosion is more prominent in the hot arid region occupying 31.7 million hectares. Removal of vegetative cover and overgrazing enhance the intensity and extent of wind erosion and desertification. The sand movement causes calcine damage to the adjoining cultivated areas, roads, canals, buildings, etc.
Alarming Rise In Dust Storms
When surfaces are denuded either at high or low altitudes by grazing and intensive cultivation, the wind starts carving up the soil and starts blowing it across the country. These are known as dust storms.
Research shows that dust storms are increasing in certain parts of the world, including China and Africa. In parts of North Africa, annual dust production has increased tenfold in the last 50 years. According to Andrew Goudie, a professor of geography at Oxford University, in Mauritania alone there were just two dust storms a year in the early 1960s, but there are about 80 a year today. Levels of Saharan dust coming off the east coast of Africa in June 2007 were five times those observed in June 2006.
The huge amounts of dust blowing across the Earth may have serious consequences for the environment. Dust storms are transporting prodigious quantities of material for very long distances. Dust storms have also been shown to increase the spread of disease across the globe as they are now combining with airborne pollutants emitted by human activities.
Also, the virus spores in the ground are blown into the atmosphere by the storms with the minute particles. Their increasing frequency could affect the levels of carbon dioxide in the atmosphere, thus directly affecting temperatures and rainfall.
Using satellite imagery, scientists are able to monitor dust storms. Modern agricultural practices, deforestation, drought, winds and increased grazing etc. contribute to dust production.
The cross-boundary nature of dust makes it a truly global issue and one that is not receiving the attention it deserves.
Research shows that dust storms are increasing in certain parts of the world, including China and Africa. In parts of North Africa, annual dust production has increased tenfold in the last 50 years. According to Andrew Goudie, a professor of geography at Oxford University, in Mauritania alone there were just two dust storms a year in the early 1960s, but there are about 80 a year today. Levels of Saharan dust coming off the east coast of Africa in June 2007 were five times those observed in June 2006.
The huge amounts of dust blowing across the Earth may have serious consequences for the environment. Dust storms are transporting prodigious quantities of material for very long distances. Dust storms have also been shown to increase the spread of disease across the globe as they are now combining with airborne pollutants emitted by human activities.
Also, the virus spores in the ground are blown into the atmosphere by the storms with the minute particles. Their increasing frequency could affect the levels of carbon dioxide in the atmosphere, thus directly affecting temperatures and rainfall.
Using satellite imagery, scientists are able to monitor dust storms. Modern agricultural practices, deforestation, drought, winds and increased grazing etc. contribute to dust production.
The cross-boundary nature of dust makes it a truly global issue and one that is not receiving the attention it deserves.
Water Erosion
Water erosion is the process by which soil and rock are removed from the Earth’s surface by water flow, and then transported and deposited in other locations.
While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. Excessive erosion causes problems such as desertification, decreases in agricultural productivity due to land degradation, sedimentation of waterways, and ecological collapse due to loss of the nutrient rich upper soil layers. Water and wind erosion are now the two primary causes of land degradation; combined, they are responsible for 84% of degraded acreage, making excessive erosion one of the most significant global environmental problems.
Industrial agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many available alternative land use practices that can curtail or limit erosion, such as terrace-building, no-till agriculture, and revegetation of denuded soils.
In India, this is the most widespread form of degradation and occurs widely in all agroclimatic zones. Soil material displacement by water can result either in loss of top-soil or in terrain deformation or both through the processes of splash erosion, sheet erosion, rill erosion and gully erosion. Soil erosion starts with the falling of the raindrops onto the bare soil surface. The impact of raindrops breaks-up surface soil aggregates and splashes particles into the air.
Soil loss assessment for different states has been carried out under a collaborative project between the National Bureau of Soil Survey and Land-Use Planning (NBSS&LUP), Nagpur, and the Central Soil and Water Conservation Research and Training Institute (CSWCR&TI), Dehra Dun.
Soil loss values were categorized into five classes (moderate, moderately severe, severe, very severe and extremely severe), and statewise areas under different categories have been determined and mapped. An area of about 126 million hectares has been found suffering from various degrees of water erosion.
Out of 69 million hectares estimated to be ‘critically’ degraded in India approximately 43 million hectares are non-arable & barren, including 4 million hectares of ravine lands. The Himalayan Mountains with weak geological formation and poor physiographic conditions are under great stress and suffer from serious water erosion though water erosion is also rampant in the Western Ghats and other areas of high intensity rainfall. Water erosion not only
removes the productive surface layer of soil but also reduces the storage capacity of reservoirs.
While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. Excessive erosion causes problems such as desertification, decreases in agricultural productivity due to land degradation, sedimentation of waterways, and ecological collapse due to loss of the nutrient rich upper soil layers. Water and wind erosion are now the two primary causes of land degradation; combined, they are responsible for 84% of degraded acreage, making excessive erosion one of the most significant global environmental problems.
Industrial agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many available alternative land use practices that can curtail or limit erosion, such as terrace-building, no-till agriculture, and revegetation of denuded soils.
In India, this is the most widespread form of degradation and occurs widely in all agroclimatic zones. Soil material displacement by water can result either in loss of top-soil or in terrain deformation or both through the processes of splash erosion, sheet erosion, rill erosion and gully erosion. Soil erosion starts with the falling of the raindrops onto the bare soil surface. The impact of raindrops breaks-up surface soil aggregates and splashes particles into the air.
Soil loss assessment for different states has been carried out under a collaborative project between the National Bureau of Soil Survey and Land-Use Planning (NBSS&LUP), Nagpur, and the Central Soil and Water Conservation Research and Training Institute (CSWCR&TI), Dehra Dun.
Soil loss values were categorized into five classes (moderate, moderately severe, severe, very severe and extremely severe), and statewise areas under different categories have been determined and mapped. An area of about 126 million hectares has been found suffering from various degrees of water erosion.
Out of 69 million hectares estimated to be ‘critically’ degraded in India approximately 43 million hectares are non-arable & barren, including 4 million hectares of ravine lands. The Himalayan Mountains with weak geological formation and poor physiographic conditions are under great stress and suffer from serious water erosion though water erosion is also rampant in the Western Ghats and other areas of high intensity rainfall. Water erosion not only
removes the productive surface layer of soil but also reduces the storage capacity of reservoirs.
Acidic Soils
In India about 6.98 Million hectares are affected by acid soils; which is about 9.4% of the total geographical area of the country.
Acidification, which may occur either because of excessive application of acidifying fertilizer or because of drainage in particular types of soil. These soils develop in humid and per-humid areas, resulting in lowering of pH and loss of soil fertility, and can be partially reclaimed by addition of chemical amendments like lime.
For assessing area under acid soils, soil maps of different states on 1 : 250,000 scale were digitized in the GIS format. The non-spatial (attribute) data on pH values were linked to master soil layer to generate soil reaction (pH) map of India, which was reclassified to produce a soil acidity map of India.
The acidity map of India, thus produced, facilitates understanding of spatial distribution and pH status of soils in different parts of India. Based on the range of pH values, the map has been reclassified as strongly acidic (pH < 4.5); moderately acidic (pH 4.5–5.5); slightly acidic (pH 5.5–6.5) and non-acidic (pH > 6.5).
However, for the estimation of the degraded lands of India, only strongly acidic - pH < 4.5 and moderately acidic – pH 4.5–5.5 soils have been considered.
Acidification, which may occur either because of excessive application of acidifying fertilizer or because of drainage in particular types of soil. These soils develop in humid and per-humid areas, resulting in lowering of pH and loss of soil fertility, and can be partially reclaimed by addition of chemical amendments like lime.
For assessing area under acid soils, soil maps of different states on 1 : 250,000 scale were digitized in the GIS format. The non-spatial (attribute) data on pH values were linked to master soil layer to generate soil reaction (pH) map of India, which was reclassified to produce a soil acidity map of India.
The acidity map of India, thus produced, facilitates understanding of spatial distribution and pH status of soils in different parts of India. Based on the range of pH values, the map has been reclassified as strongly acidic (pH < 4.5); moderately acidic (pH 4.5–5.5); slightly acidic (pH 5.5–6.5) and non-acidic (pH > 6.5).
However, for the estimation of the degraded lands of India, only strongly acidic - pH < 4.5 and moderately acidic – pH 4.5–5.5 soils have been considered.
Salt-affected soils appear in different shades of white tone with fine to coarse texture on the False Colour Composite (FCC) prints of the satellite data, owing to presence of the salts, and are recognizable under normal crop growth.
For assessing these soils, India’s National Remote Sensing Agency (NRSA) has prepared maps on 1 : 250,000 scale using satellite data. Information on the salt-affected soils provided by the Central Soil Salinity Research Institute (CSSRI), Karnal, was used for the harmonization of the degraded wasteland datasets of India. Salt-affected soils were regrouped into two classes namely saline and sodic soils in the GIS format.
Salt-affected Soils
(Salinization and Sodification)
These soils contain excessive amount of either soluble salts or exchangeable sodium or both affecting crop yields and crop production. Depending upon the physiochemical properties and the nature of the salts, the soils are classified into saline, sodic and saline-sodic.
Continuous use of poor quality groundwater for irrigation is a major factor in the development of soil salinity or sodicity, particularly in the slowly permeable soils.
It is more serious in the Indo Gangetic Plain, black soil region, arid areas of Rajasthan and Gujarat and coastal areas.
The sodic soils possess high pH and exchangeable sodium percentage values, preponderance of carbonate and bicarbonate salts of sodium, deficient amount of organic matter, nitrogen, available calcium and zinc, presence of CaC03 (kankar) in the subsoil, impaired physical condition and poor moisture relations.
Addition of a suitable amendment like gypsum is essential for reclamation of these soils.
The saline soils, on the other hand have high concentration of neutral salts mainly of chlorides and sulphates, lower values of pH and exchangeable sodium, better physical conditions etc.
Many saline soils are often associated with high water table of poor groundwater quality. Provision of adequate drainage to lower the water table and leach out the soluble salts is imperative for amelioration of such saline soils.
In India about 7 million hectares is salt-affected, of which 2.5 million hectares represents the alkali soils in the Indo-Gangetic Plain and nearly 50% of the canal-irrigated areas are affected by salinisation and/or alkalisation due to inadequate drainage, inefficient use of available water resources, and socio-political reasons.
Typical examples of salinisation caused by the rise in ground water are observed in Uttar Pradesh, Haryana, Rajasthan, Maharashtra, and Karnataka. A recent study by Sehgal and Abrol (1994) shows that a total of 10.1 million hectares is affected by salinity-alkalinity, of which about 2.5 million hectares occurs in the Indo-Gangetic Plain.
Salinity/sodicity directly affects the productivity of soils by making the soil unfavourable for good crop growth. Indirectly, it lowers productivity through adverse effects on the availability of nutrients and on the beneficial activities of soil microflora.
According to Brandon, Hommann, and Kishor (1995), the loss in crop production due to salinity in India amounts to 6.2 million tonnes (FAO data) and 9.7 million tonnes (Indian data)
In extreme cases, “damage from salinization is so great that it is technically unfeasible or totally uneconomic to reverse the process” (FAO, 1983).
Continuous use of poor quality groundwater for irrigation is a major factor in the development of soil salinity or sodicity, particularly in the slowly permeable soils.
It is more serious in the Indo Gangetic Plain, black soil region, arid areas of Rajasthan and Gujarat and coastal areas.
The sodic soils possess high pH and exchangeable sodium percentage values, preponderance of carbonate and bicarbonate salts of sodium, deficient amount of organic matter, nitrogen, available calcium and zinc, presence of CaC03 (kankar) in the subsoil, impaired physical condition and poor moisture relations.
Addition of a suitable amendment like gypsum is essential for reclamation of these soils.
The saline soils, on the other hand have high concentration of neutral salts mainly of chlorides and sulphates, lower values of pH and exchangeable sodium, better physical conditions etc.
Many saline soils are often associated with high water table of poor groundwater quality. Provision of adequate drainage to lower the water table and leach out the soluble salts is imperative for amelioration of such saline soils.
In India about 7 million hectares is salt-affected, of which 2.5 million hectares represents the alkali soils in the Indo-Gangetic Plain and nearly 50% of the canal-irrigated areas are affected by salinisation and/or alkalisation due to inadequate drainage, inefficient use of available water resources, and socio-political reasons.
Typical examples of salinisation caused by the rise in ground water are observed in Uttar Pradesh, Haryana, Rajasthan, Maharashtra, and Karnataka. A recent study by Sehgal and Abrol (1994) shows that a total of 10.1 million hectares is affected by salinity-alkalinity, of which about 2.5 million hectares occurs in the Indo-Gangetic Plain.
Salinity/sodicity directly affects the productivity of soils by making the soil unfavourable for good crop growth. Indirectly, it lowers productivity through adverse effects on the availability of nutrients and on the beneficial activities of soil microflora.
According to Brandon, Hommann, and Kishor (1995), the loss in crop production due to salinity in India amounts to 6.2 million tonnes (FAO data) and 9.7 million tonnes (Indian data)
In extreme cases, “damage from salinization is so great that it is technically unfeasible or totally uneconomic to reverse the process” (FAO, 1983).
Physical Degradation
Land degradation by physical processes is classified as barren rock and stony wastelands, mining and industrial wastelands, snow-covered and ice-caps and waterlogged areas. This information has been generated by the NRSA using satellite data. An area of 13.8 Million hectares is affected by physical degradation in India.
The Loss Of Soil Nutrients
Soil nutrients (mainly nitrogen, phosphorus and potassium) or organic matter are lost through either erosion or by cultivating on poor or moderately fertile soils, without sufficient application of manure or fertilizer. In addition, soils can be “depleted by the crops themselves, particularly if the same crops are grown on the same land year after year.” (FAO, 1983)
In India the soil nutrient loss to the tune of 5.37 to 8.40 million tonnes occurs through erosion every year.
This aggravates the problem of soil fertility depletion. The transformation from high internal input agriculture in the past to the present day high external input (fertilizers, pesticides) agriculture causes this problem.
Here the removal of plant nutrients is sustainably higher than what is added through fertilizers, thereby, resulting in a negative soil nutrient balance.
In India the soil nutrient loss to the tune of 5.37 to 8.40 million tonnes occurs through erosion every year.
This aggravates the problem of soil fertility depletion. The transformation from high internal input agriculture in the past to the present day high external input (fertilizers, pesticides) agriculture causes this problem.
Here the removal of plant nutrients is sustainably higher than what is added through fertilizers, thereby, resulting in a negative soil nutrient balance.
Also in India, it was estimated in 1990-1991 that about 8 million hectares were damaged by waterlogging or salinity from irrigation and that as many as 1.5 million farmers had been displaced by those problems since Independence.
In Pakistan “irrigated land [was] going out of production at the rate of 100 hectares a day”; many displaced farmers moved to the newly irrigated areas in Western Punjab likely to face the same situation a few years later (Maloney, 1990). Others went to swell the numbers of urban slum dwellers.
Soil Pollution
Soil contamination or soil pollution is caused by the presence of man-made chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals, or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical usage.
The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapors from the contaminants, and from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting cleanup are time consuming and expensive tasks, requiring extensive amounts of geology, hydrology, chemistry and computer modeling skills.
These pollutions of various origins can strongly reduce the agricultural potential of lands.
The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapors from the contaminants, and from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting cleanup are time consuming and expensive tasks, requiring extensive amounts of geology, hydrology, chemistry and computer modeling skills.
These pollutions of various origins can strongly reduce the agricultural potential of lands.
Soil compaction
Another cause of soil degradation and erosion from cattle is their repeated trampling over the same areas. The result is compaction or “soil pugging” due to the impact of cattle hooves. Soil compaction can destroy soil structure and results in resistance to root penetration, reduced water infiltration, and reduced aeration. All of these impacts harm beneficial soil microorganisms.
Compaction is considered to be inevitable with cattle production. However, the severity varies with the soil type, and is worst on wet soil that has a high clay content. Severe compaction provides a site for surface runoff that can result in serious erosion and even the creation of deep trenches, a process called gullying.
Usage of heavy machinery like tractors, particularly in wet soils, is obviously another cause of soil compaction. In many areas, compaction is not easy to correct.
Compaction is considered to be inevitable with cattle production. However, the severity varies with the soil type, and is worst on wet soil that has a high clay content. Severe compaction provides a site for surface runoff that can result in serious erosion and even the creation of deep trenches, a process called gullying.
Usage of heavy machinery like tractors, particularly in wet soils, is obviously another cause of soil compaction. In many areas, compaction is not easy to correct.
Waterlogging
Waterlogging is the rise of the water table to the root zone of plants, caused by an excessive input of water with respect to drainage capacities. It is typical of irrigated areas, but may also occur through river flooding. Waterlogging also increases salinity. As with salinization, the causes of waterlogging are in part physical and in part related to agricultural practices, namely inappropriate irrigation.
In India, roughly an area of 100,000 ha is estimated to be affected by water logging annually. Introduction of canal irrigation is the major reason for the once fertile lands to be affected by water logging (e.g., Hissar, Haryana). The menace of water logging has also taken place in the Indira Gandhi Nahar Project, which was initiated in 1961.
Such phenomena have occurred on a large scale in several parts of canal command areas such as the Indo-Gangetic plains and many other arid, semi-arid and sub-humid tracts of the country. Large areas have been rendered barren due to this.
In India, roughly an area of 100,000 ha is estimated to be affected by water logging annually. Introduction of canal irrigation is the major reason for the once fertile lands to be affected by water logging (e.g., Hissar, Haryana). The menace of water logging has also taken place in the Indira Gandhi Nahar Project, which was initiated in 1961.
Such phenomena have occurred on a large scale in several parts of canal command areas such as the Indo-Gangetic plains and many other arid, semi-arid and sub-humid tracts of the country. Large areas have been rendered barren due to this.
Soil Poisoning
Farmland is occasionally poisoned with chemicals. While pesticides and even fertilizers are sometimes suspected of causing soil impairment, the damage in most cases is not permanent. However, some apple orchards sprayed with arsenic compounds in the 1930s were reported as still unproductive 30 years later. In recent years, there has been a general movement in many developed countries against using the more persistent insecticides, including a chemical group that includes DDT and chlordane. Radioactive fallout also caused public concern during the period of nuclear bomb tests.
Today a more serious problem is the indiscriminate dumping of chemical wastes, some of which are extremely toxic to plants, animals, and man and some of which contains dangerous heavy metals which can be taken up by plants.
Today a more serious problem is the indiscriminate dumping of chemical wastes, some of which are extremely toxic to plants, animals, and man and some of which contains dangerous heavy metals which can be taken up by plants.
Heavy metals
The pollution of soil with heavy metals due to improper disposal of industrial effluents, use of domestic and municipal wastes and pesticides, is becoming a major concern. Though no reliable estimates are available of the extent and degree of this type of soil degradation, it is believed that the problem is extensive and its effects are significant. Some commercial fertilisers also contain appreciable quantities of heavy metals, which have undesirable effects on the environment. The indiscriminate use of agro-chemicals such as fertilisers and pesticides is often responsible for land degradation.
Sheet Erosion
There are several types of man-made erosions but most of them are clearly recognizable. But one of the most insidious one is the invisible or sheet erosion. This occurs when a thin layer or “sheet” of soil from a field is removed. It is insidious because the amount of soil seen to be removed is usually so small in any given year that a farmer often fails to notice that erosion is occurring. Occasionally he becomes aware of sheet erosion only after he notices that a formerly buried object - a rock, the lower portion of a fence post, or root of a tree - is suddenly exposed.
However, sheet erosion removes great quantities of topsoil. Even a very thin layer of soil, only slightly thicker than a piece of wrapping paper, when transported down a slope, can weigh several tons per hectare. It does not take many years or many rainstorms for losses from sheet erosion to become significant.
However, sheet erosion removes great quantities of topsoil. Even a very thin layer of soil, only slightly thicker than a piece of wrapping paper, when transported down a slope, can weigh several tons per hectare. It does not take many years or many rainstorms for losses from sheet erosion to become significant.
By God’s arrangement one can have enough food grains, enough milk, enough fruits and vegetables, and nice clear river water. But now I have seen, while traveling in Europe, that all the rivers there have become nasty. In Germany, in France, and also in Russia and America I have seen that the rivers are nasty. By nature’s way the water in the ocean is kept clear like crystal, and the same water is transferred to the rivers, but without salt, so that one may take nice water from the river. This is nature’s way, and nature’s way means Krsna’s way.
~ Srila Prabhupada (Teachings of Queen Kunti 23)
