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International Journal of Scientific Research in Agricultural Sciences, 1(4), pp. 50-55, 2014
Available online at http://www.ijsrpub.com/ijsras
ISSN: 2345-6795; ©2014 IJSRPUB
http://dx.doi.org/10.12983/ijsras-2014-p0050-0055
50
Editorial Publication
Soil Degradation: A Challenge to Sustainable Agriculture
Afroz Alam
Department of Bioscience and Biotechnology, Banasthali Vidyapith, Tonk-304 022 (Rajasthan), India
*Corresponding Author: afrozalamsafvi@gmail.com
Received 10 June 2014; Accepted 04 July 2014
Abstract. Agricultural practices have a substantial impact on many ecosystems worldwide, and give rise to variety of
ecological problems. Soil degradation is one the key areas in which agriculture impacts upon ecology. Soil erosion is a result
of poor farming practices which cause removal of vegetation cover from soils, the use of large fields without boundaries to
slow water movement and inappropriate ploughing techniques all stimulate soil erosion. Salinity of soil is another important
factor which limits the use of this natural resource. In present review the causes, the cost of soil erosion and certain soil
conservation practices have been discussed.
Keywords: Agriculture, conservation, degradation, erosion, farming, soil, salinity.
1. INTRODUCTION
Few ecosystems worldwide escape the impact of
human activity, and one pervasive influence is
agricultural activity, which necessarily involves gross
changes to the local ecosystem, and may have more
wide-reaching effects (Eswaran et al., 1997a).
Conservation and augmentation of quality of
natural resources principally of soil and water are the
central to ensuring food security of the growing
population. Ever-increasing salinity of these two
principal resources along with soil erosion is the
foremost restraint on our capacity for sustainable
agriculture to ensure food security. To avoid the
productive lands from getting salinized as well as to
make use of the existing salty land and water, it is
necessary to correct the harmful condition through
application of proper technology.
Soil degradation is the decline in soil characteristic
originated by its inappropriate use, typically for
agricultural, pastural, industrial or urban causes
(Johnson and Lewis, 1995). It is a severe universal
ecological crisis and may be aggravated by weather
change. Soil degradation is one of the most important
threats facing mankind which not only weakens the
productive capability of an ecosystem but also affects
overall climate (Barrow, 1991). Having already
affected more than two billion hectares of land
globally, the typical rate of soil degradation is almost
8-9 m ha/yr as per FAO/UNEP recent approximation.
A large fraction of Indian land shows clear indication
of advanced and nonstop degradation, frightening to
destabilize our capacity to augment food production
and improve pastoral poverty. The socio-economic
and ecological consequences are massive (Beinroth et
al., 1994).
It has been estimated that due to desertification and
soil erosion the productivity of some lands has
declined by 50%. For instance, in African countries,
the yield reduction due to previous soil erosion may
range from 2 to 40%, with an average loss of 8.2% for
the continent (Darkoh, 1995; Eswaran et al., 1997b).
Likewise, in South Asia, annual loss in productivity is
estimated at 36 million tons of cereal equivalent
valued at US$5,400 million by water erosion, and
US$1,800 million due to wind erosion. Globally the
annual loss of 75 billion tons of soil costs the world
about US$400 billion per year, or approximately
US$70 per person per year (Crosson, 1997).
Just about 3% of the global land surface can be
regarded as or Class I land (Prime) and this is not
occur in the tropics (Lal, 1994; 2009). An added 8%
of land is in Classes II and III. This 11% of land must
give food to the six billion people today and the 7.6
billion expected in 2020. Desertification is
experienced on 33% of the global land surface and
affects more than one billion people (Darkoh, 1995).
1.1. The causes of soil degradation
Good soil produces good vegetation which provides
food and habitat for animals. A major concern of good
Alam
Soil Degradation: A Challenge to Sustainable Agriculture
51
soil management is keeping soil in place and
maintaining its fertility. Once lost soil is irreplaceable
i.e. 1 cm of soil may take more than 500 years to
form, yet can be lost within a year. Soil erosion and
the loss of fertility due to salinity as a result of poor
farming practices are serious problems globally
(Hartemink, 1995). Indigenous systems are
insufficient alone to prevent agricultural land from
continuing to loss productive soil, water and nutrient
resources. This is partly because not all farmland is
protected by conservation measures, but also because
not all erosion arises from farmland. Both roads and
urban areas concentrates water flows and
nonagricultural areas are also subjected to erosion.
Farmers may not be conserving soil and water due to
lack of local knowledge and skills, or they may be
unwilling to invest in conservation measures if the
economic cost is greater than the benefits (Oldeman et
al., 1992). For instance, the high price of wheat has
encouraged winter cultivation in fragile environments,
which has led to a large increase in soil erosion
(UNEP, 1992; 1993; 1994). Soil erosion can in the
order of 30-100 tons per hectare in fields where
hedges have been removed. Erosion is greatest where
there is little vegetation cover, such as during winter,
and when slopes are long, such as big fields
(Fahnestock et al., 1995). To farmers, erosion reduces
the biological productivity of soils and the capacity to
sustain productivity in the future. Soil erosion may
also cause widespread flooding as soil becomes less
able to retain water. The importance of land
degradation among global issues is increased because
of its blow on world food security and quality of the
environment. High population density is not
essentially related to land deprivation; it is what a
inhabitants does to the land that decides the extent of
dreadful conditions. Inhabitants can be a major
advantage in overturning a trend towards degradation.
Nevertheless, they need to be politically strong and
economically motivated to care for the land, as
survival agriculture, scarcity, and illiteracy can be
important causes of land and environmental
degradation (Mermut and Eswaran, 1997).
Ecosystem services provided by soils are vital to
the carbon and water cycles and include cultural
functions. There are strong links between climate
change and soil condition (Virmani et al., 1994).
In simple terms, soil degradation includes physical,
chemical and biological deterioration. Examples of
soil degradation are loss of organic matter,
unfavorable changes in salinity, acidity or alkalinity,
and the effects of toxic chemicals, decreased soil
fertility, decline in structural state, erosion, pollutants
or excessive flooding.
Fig. 1: Types of Land degradation
International Journal of Scientific Research in Agricultural Sciences, 1(4), pp. 50-55, 2014
52
Degradation possibly caused physically by taking
away of top soil through water and wind erosion,
reduced capability to store water, augmented
receptiveness to overflow and gradual absorption of
soluble salts in root zone (Fig. 1). Overgrazing,
increase of canal irrigation, unrestrained urbanization
and surface mining etc. are some of the other actions
that prop up degradation of soil.
Chemical degradation results in internal soil
corrosion resulting from buildup of chemical
substances like salts or loss of nutrients in addition
through physical processes including water logging.
The influences of physical and chemical degradation
are straightforwardly noticeable. But the cost of
biological degradation caused due to decline in
organic matter, biomass carbon, decline in diversity
and activity of flora and fauna are more restrained.
Salinity is the buildup of salt in soil and water to a
level that impacts on the normal and built
surroundings. Salinity occurs naturally in several parts
of the landscape but in several cases has been worsens
where human activities hasten the mobilization and
buildup of salt. Today extend of salinity impacts
farms, wetlands, rivers, irrigation areas, drinking
water and infrastructure. It is a global issue at present.
It has taken many decades for the problem to appear
and will be with us for a long time to come. Solving it
is a shared responsibility involving land managers,
conservationists, native communities, scientists,
businesses and all levels of government (Mackenzie et
al., 1999).
Salinization is a prevalent problem in irrigated
agriculture, dropping the world's irrigated area by 1–
2% each year. The salinization badly affects
agricultural land right across the country, but is most
severe in dry areas such as Rajasthan. As a result crop
growth and yield are poor in this particular region.
This situation hits badly on the livelihood of farmers,
reducing their profits or even forcing them their land.
Reducing the consequence of salinization in
agriculture is decisive for attaining food security. But
in India and other affected countries, lucid approaches
for reducing or managing salinity in agriculture are
inadequate.
1.2. The cost of Soil degradation
Most agricultural systems are based on short term-
economic gain and as soil erosion occurs so gradually
that it is almost imperceptible it may not, in the short-
term, appears serious. Fifteen tons of soil lost from a
hectare of land in single storm will diminish soil depth
by 1 mm. However, tons of soil is ejected from
various rivers into respective gulfs ever second.
Eroded soil is not simply a loss of a valuable resource;
it can cause air, water and land pollution. The great
soil erosion event of the south and southwest USA in
the 1930s lead to the area being called the ‘Dust bowl’
from the level of air pollution.
The main blow of soil degradation is a
considerable reduction in the productivity of soil and
land directly affecting those whose employment
depends on this natural source. There are adequate
evidences (Blaikie and Brookfield, 1987; Barrow,
1991; Johnson and Lewis, 1995) that undoubtedly
reveal the fact that land degradation affects all aspects
of life.
Certain agricultural practices also diminish soil
fertility. Soil that is continually cropped or grazed will
eventually lose its fertility because the normal cycle
that returns mineral-rich dead plant matter to the soil
is disrupted. Soil compaction that results from the use
of heavy machinery can destroy the structure of soil,
restrict water infiltration and lead to increased erosion.
The problem of soil erosion is greatest in the third
World where extensive areas of land are cleared for
food production. Population growth puts stress on the
need for increased agricultural production as well as
the clearing of land for cropping and firewood
supplies (Sajjapongse, 1998).
However, despite these problems, some efforts to
improve erosion control have been successful. In
Ethiopia, walls of rock and earth are built across
hillsides to catch eroding soil. This forms natural
terraces to help reduce further erosion. In Australia,
wide-spread use of fencerows and hedgerows as
physical barriers helps prevent wind erosion of
agricultural fields (Mackenzie et al., 1999).
1.3. Soil conservation practices
Many issues that deal with those working in the
domain of land resources comprise technologies to
decrease degradation and also the techniques to
evaluate and observe land degradation. A number of
difficulties remain unreciprocated and these include
predictability of land degradation, sufficiency of early
warning indicators of land degradation, absence of
land tenure and the resulting lack of stewardship,
societal responsibility of soil scientists regarding
anthropogenic induced decline in soil quality,
development of full proof public policy, international
collaboration to reduce the problem at global level,
quantification of the aesthetic value of land,
quantification of consumption of land etc (Stocking,
1986).
There are three steps involved in the management
of the problem: assessment, monitoring, and
application of mitigating technologies. All three steps
are in the tasks of agriculturists and particularly, soil
scientists. The last step without a doubt has the job for
soil science, and over the past decade considerable
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Soil Degradation: A Challenge to Sustainable Agriculture
53
advancement has been made in awaking the dangers
of land degradation (Mabbutt, 1992).
Soil science has made noteworthy aid to the
mission of soil resource assessment but its users have
shown modest or no curiosity in the additional task of
monitoring the resource base (Mermut and Eswaran,
1997; Tilman et al., 2002). This still remains a new
area of investigation requiring guidelines, standards,
and procedures. The challenge is to accept an
internationally good enough method for this task. Soil
scientists have a compulsion not only to show the
spatial distribution of stressed systems but also to
provide realistic estimates of their rates of
degradation. They should develop early warning
indicators of degradation to allow them to collaborate
with others, such as social scientists, to develop and
implement mitigating technologies. Soil scientists also
have a role in assisting national decision-makers to
develop appropriate land use policies.
1.4. Challenges and Management Strategies
Land degradation remains a serious global threat but
the science concerning it contains both myths and
facts (Greenland et al., 1994). The debate is
perpetuated by confusion, misunderstanding, and
misinterpretation of the available information. There
are many, usually puzzling, reasons why land users
allow their land to degrade. Many of the reasons are
related to community opinions of land and the values
they place on land. Degradation is also a slow
unnoticeable process and so many people are not
conscious that their land is degrading. Creating
awareness and building up a sense of stewardship are
important steps in the challenge of reducing
degradation. Accordingly, suitable technology is only
a fractional response. The key resolution lies in the
behaviour of the farmer who is subject to economic
and social pressures of the community/country in
which they live. Food security, environmental
balance, and land degradation are strongly inter-linked
and each must be addressed in the context of the other
to have measurable impact (Pimentel et al., 1995).
Important challenges include: Encouragement of
the scientific community to build up an integrated
programme for methods, standards, data collection,
and research networks for evaluation and monitoring
of soil and land degradation. Improvement of land use
models that put together both natural and human-
induced factors that contribute to land degradation and
that could be used for land use planning and
management. Strengthening of the information
systems that connect environmental monitoring,
accounting, and impact depth to land degradation,
development of strategies that persuades sustainable
land use and management and assist in the greater use
of land resource information for sustainable
agriculture. Making certain economic instruments for
the assessment of land ruin and encourage the
sustainable use of land resources, rationalization of
the wide range of terminology and definitions with
different meanings among different regulations
associated with land degradation. Regularity of
evaluation methods for the extent of land degradation.
Development of non-uniform criteria for evaluating
the severity of land degradation. Get the better of the
difficulty in evaluating the on-farm economic impact
of land degradation on productivity. There is an
urgent need to address these issues through a multi-
disciplinary approach, but the most urgent need is to
develop an objective, quantifiable, and precise
concept based on scientific principles.
2. CONCLUSION
It has been known for some time that a number of
methods can be engaged to reduce soil erosion. By
ploughing a field at right angles to the slope, furrows
follow the contours of land rather than the slope. By
using this contour ploughing system, water erosion is
reduced. Planting crops on areas of bare field helps to
prevent soil erosion. If leguminous (Family Fabaceae)
plants are used as cover crops, nitrogen will be fixed
and the nitrogen content of the soil increased. No-till
farming is a system that consists of planting a narrow
slit trench without ploughing the soil. By reducing soil
disturbance, soil erosion is reduced (Ruppenthal,
1995). These systems, along with crop rotation can all
be used to decrease soil loss and fertility. However,
although these techniques are widely known, progress
has been slow in establishing these practices. In
addition, no-tilling farming often uses herbicides,
invoking other problems. Therefore an international
effort is required to combat this ever increasing
problem for sustainable agriculture (UNCED, 1992).
Organization like ICARDA is one such effort which is
doing serious work in this direction through its nation
partnerships with agricultural ministries and research
agencies in Central Asia, Iraq, Iran and Egypt by
providing research-based surviving tactics for farmers
and water managers dealing with salinization. Their
experience, the practices developed with partners, and
research is also beneficial for other areas of the world
where agricultural production is threatened by
increasing levels of salinity, including India, Pakistan,
China and other nations.
REFERENCES
Barrow CJ (1991). Land Degradation: Development
and Breakdown of Terrestrial
International Journal of Scientific Research in Agricultural Sciences, 1(4), pp. 50-55, 2014
54
Environments.Cambridge: Cambridge
University Press.
Beinroth FH, Eswaran H, Reich PF, Van Den Berg E
(1994). Land related stresses in
agroecosystems. In: Stressed Ecosystems and
Sustainable Agriculture, eds. S.M. Virmani,
J.C. Katyal, H. Eswaran, and I.P. Abrol. New
Delhi: Oxford and IBH.
Blaikie P, Brookfield H (1987). Land Degradation and
Society. London: Methuen.
Crosson PR (1997). The on-farm economic costs of
erosion. In: Methods for Assessment of Land
Degradation, eds. R. Lal, W.E.H. Blum, C.
Valentin and B.A. Stewart. Boca Raton: CRC.
Darkoh MK (1995). The deterioration of the
environment in Africa’s drylands and river
basins. Desertification Control Bulletin, 24, 35–
41.
Eswaran H, Reich PF, Beinroth FH (1997a). Global
distribution of soils with acidity. In: Plant-Soil
Interactions at Low pH: Sustainable Agriculture
and Forestry Production. eds. A.Z. Moniz,
A.M.C. Furlani, R.E. Schaffert, N.K. Fageria,
C.A. Rosolem and H. Cantarella, 159–164.
(Proceedings of the 4th International
Symposium on Plant-Soil Interactions at Low
pH, Belo Horizonte, Minas Gerais, Brazil.)
Eswaran H, Almaraz R, Reich PF, Zdruli PF (1997b).
Soil quality and soil productivity in Africa.
Journal of Sustainable Agriculture,10, 75–94.
Fahnestock P, Lal R, Hall GF (1995). Land use and
erosional effects on two Ohio Alfisols. Crop
yields. Journal of Sustainable Agriculture, 7,
85–100.
Greenland DJ, Bowen G, Eswaran H, Rhoades R,
Valentin C (1994). Soil, Water, and Nutrient
Management Research: A New Agenda.
IBSRAM Position Paper. Bangkok: IBSRAM.
Hartemink AE (1995). Land fertility decline under
sisal cultivation in Tanzania. ISRIC Technical
Paper 28. Wageningen: ISRIC.
Johnson Dl, Lewis La (1995). Land Degradation:
Creation and Destruction. Oxford: Blackwell.
Lal R (1994). Tillage effects on soil degradation, soil
resilience, soil quality, and sustainability. Soil
Tillage Research,27, 1–8.
Lal R (2009). Soils and Sustainable Agriculture: A
Review. In: Sustainable Agriculture. eds. E.
Lichtfouse et al., 15-23.
Mabbutt JA (1992). Degradation of the Australian
drylands: a historical approach. In: Degradation
and Restoration of Arid Lands, ed. H.E.
Dregne, 27–98. Lubbock: Texas Technical
University.
Mackenzie A, Ball AS, Virdee SR (1999). The
ecology of agriculture. Instant Notes in
Ecology. Viva Book Private Limited. New
Delhi, 295-298.
Mermut AR, Eswaran H (1997). Opportunities for soil
science in a milieu of reduced funds. Canadian
Journal of Soil Science, 77, 1–7.
Oldeman LR, Hakkeling RTA, Sombroek WG (1992).
World Map of the Status of Human-induced
Soil Degradation: An Explanatory Note.
Wageningen: ISRIC.
Pimentel D, Harvey C, Resosudarmo P, Sinclair K,
Kurz D, Mcnair M, Crist S, Shpritz L, Fitton L,
Saffouri R, Blair R (1995). Environmental and
economic costs of soil erosion. Science, 267,
1117–1123.
Ruppenthal M (1995). Soil Conservation in Andean
Cropping Systems: Soil Erosion and Crop
Productivity in Traditional and Forage-Legume
Based Cassava Cropping Systems in the South
Colombian Andes. Weikersheim: Verlag Josef
Margraf.
Sajjapongse A (1998). ASIALAND Management of
Sloping Lands Network: An Overview of Phase
3.Network Document No. 23, Bangkok:
IBSRAM.
Stocking M (1986). The cost of soil erosion in
Zimbabwe in terms of the loss of three major
nutrients. Consultant’s Working Paper No. 3.,
Soil Conservation Programme. Rome: FAO
Land and Water Division.
Tilman D, Kenneth G, Cassman, Pamela A, Matson,
Rosamond N, Polasky S (2002). Agricultural
sustainability and intensive production
practices. Nature, 318, 671-677.
UNCED (1992). United Nations Conference on
Environment and Development. Rio de Janeiro:
UN.
UNEP (1992). World Atlas of Desertification.
London: Edward Arnold.
UNEP (1993). Good news in the fight against
desertification. Desertification Control Bulletin,
22, 3.
UNEP (1994). Land Degradation in South Asia: Its
Severity, Causes and Effects upon the People.
INDP/UNEP/FAO. World Soil Resources
Report 78. Rome: FAO.
Virmani SM, Katyal JC, Eswaran H, Abrol I Eds.
(1994). Stressed Agroecosystems and
Sustainable Agriculture. New Delhi: Oxford
and IBH.
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Soil Degradation: A Challenge to Sustainable Agriculture
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Dr. Afroz Alam, working as Associate Professor in the Department of Bioscience and
Biotechnology, Banasthali University, Rajasthan. He is currently supervising seven Ph. D.
students in different aspects of Plant Science. He has vast experience of teaching and research in
plant science. He has over 60 research publications in prestigious International and National
Journals and a 4 text books with reputed publication houses to his credit. He is life member of
various associations of Plant Sciences.
