Land is a complex, multi-component natural entity that becomes a resource base when used for a specific purpose or purposes. Land degradation is a concept in which the value of the biophysical environment is affected by one or more combination of natural and human-induced processes acting upon the land. It is a temporary or Permanent decline in the productive capacity of land. It is also the reduction in the capability of the land to produce benefits from a particular land use under a specified form of land management. Major forms of land degradation are water and wind erosion, desertification and chemical erosion. Urban expansion is also a form of land degradation. Negative effects of land degradation affect heavily on environment and economy which is a cause of grave concern. Land degradation has significant costs, particularly in developing countries (Rosegrant and Ringler, 1991). It does not only reduces farm productivity affecting livelihood and regional economies, it also leads to reduced biodiversity. Land degradation in most developing countries is becoming a major constraint to future growth and development. About 40-75% of the world’s agricultural land’s productivity is reduced due to land degradation (IFPRI, 2001). Increased support for research and extension to increase crop yields is crucial to meeting the needs of a growing human population for food, biomass energy, fiber, and timber. There is a need to increase support to biodiversity preservation by alleviating pressure to convert remaining natural habitat to croplands. There is a need for more public investments to support SLM to slow land degradation.

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2. This conference presentation emphasis on:
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Land degradation, a global concern.
Land physical degradation (soil physical erosion due to water
and wind)
Causes and effects of land degradation.
Cost of land physical degradation (estimating costs due to
water erosion-a case study)
Land degradation concerns in Afghanistan-what needs to be
done.

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 Land is a complex, multi-component natural entity that becomes a
resource base when used for a specific purpose or purposes.
 Land degradation is a concept in which the value of the biophysical
environment is affected by one or more combination of natural and
human-induced processes acting upon the land.
 Temporary or Permanent decline in the productive capacity of land.
 It is also the reduction in the capability of the land to produce
benefits from a particular land use under a specified form of land
management
 Net productive change reflects both natural and human induced
processes of degradation and improvement.

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Introduction cont…
 Agricultural productivity has risen dramatically, but cost of land
degradation has also risen.
 Major forms of land degradation are water and wind erosion,
desertification and chemical erosion.
 Urban expansion is also a form of land degradation
 Negative effects of land degradation affect heavily on environment
and economy - cause of grave concern.

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POPULATION
DEGRADATION
LAND
Pressures: direct and indirect pressures
 Direct pressures: deforestation & erosion.
 Indirect pressures: Population - Fragmentation of holdings-
Land degradation(Fig.1)

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Fig 2: Cause and effect of agricultural land degradation

7.  Land degradation has significant costs, particularly in
developing countries (Rosegrant and Ringler, 1991).
 It does not only reduces farm productivity affecting
livelihood and regional economies, it also leads to
reduced biodiversity.
 Land degradation in most developing countries is
becoming a major constraint to future growth and
development (Raina, Joshi and Kolarkar, 2001; Reddy
2003).
 About 40-75% of the world’s agricultural land’s
productivity is reduced due to land degradation
(IFPRI, 2001).
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Table 1: Estimates of all degraded lands (in million km2
) in dry areas in the
world
Continent Total area Degraded area
% degraded
area
Africa 14.326 10.458 73
Asia 18.814 13.417 71
Australia and the
Pacific
7.012 3.759 54
Europe 1.456 0.943 65
North America 5.782 4.286 74
South America 4.207 3.058 73
Total 51.597 35.922 70
Source: Dregne and Chou, 2001

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Table2 : Extent of land degradation vulnerability in SAARC
Countries
Source: UNEP (2014)

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( natural processes and human activities)
1) Wind and water erosion
2)Over drafting
3)Land pollution
4)Increased mechanization
5) Increased urbanization
6)Increased agricultural land and field size
7) Droughts
8)Herbicides
9) Fungicides
10) Insecticides
11) Increased waste disposal
12) pesticides
13) Weeds

11. On-site Off-site
Soil loss Sedimentation of lakes and rivers
Nutrient loss Drop in the capacity of water bodies
to receive water
Drop in the soil’s chemical, physical
and biological fertility
Flooding
Damage to plantations Landslides
Yield drop Flash floods
Production loss Destruction of roads, railways,
waterways and other public assets
Shrinkage of the available planting
area
Loss of biodiversity
Loss of water quality
Drop in food supply
Inflated food prices & food insecurity
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Table3: Losses caused by soil physical erosion, on-site and off-site
Source: http://www.scielo.br

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 water and wind erosion
 Desertification
 soil acidification
 Soil Salinization
 Water logging
 Soil alkalinization

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Water and wind erosion:Erosion is the carrying away or displacement of solids
(sediment, soil, rock and other particles) usually by the agents such as wind,
water.
Causes
Climatic factors
Geological factors
amount and intensity of precipitation, seasonality, wind speed,
storm frequency.
sediment or rock type, its porosity and permeability, the slope
(gradient) of land.

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Table 4: Estimates of the global extent of agricultural land degradation
Type Light Moderate
Strong +
extreme
Total
Water erosion 3.43 5.27 2.24 10.94
Wind erosion 2.69 2.54 0.26 5.49
Chemical
degradation
0.93 1.03 0.43 2.39
Soil
compaction
0.44 0.27 0.12 0.83
Total 7.49 9.11 3.05 19.65
Source: http://www.kwaad.net/EconomicCostsOfSoilErosion
(in million km2)

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Figure3 :Cost of soil erosion from water (billion USD)
Source: http://www.kwaad.net/EconomicCostsOfSoilErosion
Europe North
America
East
Asia
Africa
West Asia South
Asia
Latin
America

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Salinization is the process by which water-soluble salts accumulate in
the soil.

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Salt in soils decreases the osmotic potential of the soil so that plants can’t
take up water from it.
causes
The presence of soluble salts, such as sulfates of sodium,
calcium, and magnesium in the soil
A high water table
A high rate of evaporation
Low annual rainfall
Management
i) Recharge management

19. 19Soil acidification is a process by which soil PH decreases over time.

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Acidification can affect either the surface soil only, or the subsoil as well.
Causes of Acidity
i) Soil acidity occurs naturally in higher rainfall areas.
ii) Agricultural production also increases acidity through unbalanced nitrogen cycling
Preventive measures
Use acid tolerant species (native grasses)
Use better irrigation management practices

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Table 5: Expected loss of productivity due to acidification
Class pH Degree Loss of
productivity(%)
0 6.5 Nil Nil
1 5.5-6.5 Slight Upto 10
2 4.5-5.5 Moderate 10-25
3 3.5-4.5 Strong 25-50
4 <3.5 Extreme >50
www.scielo.br

22. 22 Destruction of the biological potential of the land, which could lead ultimately
to the formation of desert-like conditions.

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Land Degradation Costs
 Income Foregone: Productivity losses due to land degradation - annual
value of agricultural production foregone due to degradation.
 Cost of Rehabilitation: costs incurred for stopping further degradation and
to restore the land to its original undegraded condition

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Table 6: Income foregone due to desertification
Continent Irrigated
land
Rainfed
cropland
Rangeland Total
Africa 476 1,857 6,966 9299
Asia 7,953 4,657 8,313 20923
Australia and
Newzealand
62 544 2,529
3135
Europe 476 450 564 1490
North America 1,465 441 2,878 4784
South America 354 252 2,084 2690
World 10,786 8,191 23,334 42311
Total income foregone = $ 4231 million / yr due to desertification
$250 per hectare for land at least moderately desertified in irrigated land
$38 per hectare for land at least moderately desertified in rainfed cropland
$7 per hectare for land at least moderately desertified in rangeland
Source: Dregne and Chou,
(million$/year)

25. 25Stagnation/pooling of water on the land surface for significant duration.

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Water logging is when the soil surface area becomes saturated.
Soil pores (spaces) are full of water. Excess water cannot drain away.
Causes
Periods of heavy rain
Poor irrigation management.
Poor drainage
Prevention
•Management of drainage lines for efficient water flow
•Increase deep rooting vegetation for greater utilization of water from the soil
•Only apply water when necessary

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 soils with a relatively high exchangeable sodium percentage, a relative
high pH (> 9), a poor soil structure and a low infiltration capacity.

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Causes
The natural cause is the presence soil minerals producing sodium carbonate
(Na2CO3).
The man-made cause is the application of irrigation water (surface or
ground water) containing a relatively high proportion of sodium bicarbonates.
o By adding acidifying minerals like pyrite
Control
o Deep ploughing and incorporating the subsoil into the top soil
o Grass cultures

29. Case Study
 Economic Valuation of Soil Erosion on Cultivated
lands, Gorontalo, Indonesia
R.H. Anasiru, M.L. Rayes and Budi Setiawan, (2013), Economic Valuation of Soil
Erosion on Cultivated lands in Langge Sub-watershed, Gorontalo, Indonesia,
Journal of Natural Sciences Research, Vol.3, No.8, 2013
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30. Introduction of the case study:
 Soil erosion is processes of destruction of soil particles that often
suggest large economic impacts.
 Many cases of topsoil losses are caused by the intense rainfall
and soil material transport by surface run-off. These events have
various negative economic impacts on agriculture.
 This study aims to analyze economic value of soil erosion on
cultivated lands in Gorontalo province, Indonesia. Total economic
value of natural resources is the amount of use value and non-use
value.
 In this study, calculation of economic value is focused on use
value, related to the soil fertility losses.
 Calculation of economic values is based on the cost-based method
by estimating any replacement cost.
 Therefore, estimation of the loss value caused by soil erosion is
based on value of organic fertilizers, Urea, SP-36 and KCl.
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31. Table 7: Total Economic Value of Soil Erosion in Gorontalo
Indonesia
March April May June July Total
Rainfall (mm) 374 125 87.5 67 202 855.5
Sediment (t/h) 3.99 0.14 0.06 0.06 2.87 7.12
Nutrient Losses (Kg/ha):
Carbon 49.05 1.75 0.79 0.77 35.24 87.6
Nitrogen 5.2 0.2 0.08 0.08 3.73 9.26
Phosphorus 0.78 0.03 0.01 0.01 0.56 1.4
Potassium 4.5 0.16 0.07 0.07 3.23 8.04
Economic Value (USD/ha) of nutrient losses base on price of:
Organic fertilizer 4.4 3.1 2.7 2.3 3.3 15.8
urea 42 12 14 14 32 114
Sp-36 40 25 21 15 29 130
KCl 31.1 9 7 6 16 69.1
Total Economic
Value(usd/ha) 157.1 77 69 58 110 328.9
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Source: R.H. Anasiru, M.L. Rayes and Budi Setiawan, (2013)

32. 1. Natural hazards e.g flood, drought, snow melt, etc.
2. Erosion by water and wind (e.g. serious land erosion
from river water, wind erosion in the west of the
country)
3. Deforestation, shrinkage of vegetation cover on land,
overgrazing (natural and/or human induced)
4. Inappropriate management in cultivation of land on
steep slopes (human induced)
5. Inadequate nutrient replenishment (human induced)
6. Soil organic matter depletion
7. Desertification
8. Over drafting
Source: www.saarcagri.net
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The causes of land degradation, natural or human induced
in Afghanistan:

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Around 80 % land
is vulnerable to be
degraded
West and east
of the country
is more
vulnerable
Source: http://fscluster.org

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Conclusions
 Land is the basis of production, which is degraded by natural causes
and also largely by human activities.
Degradation results in loss of intergenerational equity and the value of
bequests
Land degradation will remain an important global issue for the 21st century
Land degradation often destroys or reduces agricultural production
and productivity the natural beauty of landscapes which eventually
cause economic loss, poverty and food insecurity
Estimating erosion costs helps economic agencies in decision-
making on soil conservation policy and provides governments with
tangible evidence of the need to implement public policies aimed at
ensuring the sustainable development of economic activities linked to
the farming sector.
A very high percentage of land is vulnerable to degradation (specially
soil physical erosion in Afghanistan, a cause of high concern.
Land is often a limiting factor of economic output, and thus its
degradation may further undermine the prospects of economic
growth in Afghanistan.

35.  Increased support for research and extension to
increase crop yields is crucial to meeting the needs of a
growing human population for food, biomass energy,
fiber, and timber.
 A special need for research on land physical
degradation in Afghanistan.
 As underground water table is lowering due to over
drafting in Afghanistan so rain water harvest
techniques is very important to be adopted by our
farmers, it also reduces water erosion.
 There is a need to increase support to biodiversity
preservation by alleviating pressure to convert
remaining natural habitat to croplands.
 There is a need for more public investments to support
SLM to slow land degradation.
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Policy Implications

36. References:
1. Dregne and Chou, (2004), Global Desertification Dimensions and Costs In
“Degradation and Restoration in Arid Lands, International Centre for Arid and
Semiarid Land Studies, Texus Technical University.
2. Rosegrant and Ringler, )1997 (Agricultural Research, Integrated economic‐
hydrologic water modeling at the basin scale: The Maipo River basin., journal of
agricultural economics. 3(1)
3. Raina,P, D.C. Joshi and A.S. Kolarkar, (2003) Land Degradation mapping by
remote sensing in the arid region of India. Soil Use and Management. 7(1):47-52.
4. R.H. Anasiru, M.L. Rayes and Budi Setiawan, (2013), Economic Valuation of
Soil Erosion on Cultivated Drylands in Langge Sub-watershed, Gorontalo,
Indonesia, Journal of Natural Sciences Research, Vol.3, No.8, 2013
5. http://www.kwaad.net/EconomicCostsOfSoilErosion
6. http://fscluster.org
7. www.saarcagri.net/strategiesforarrestinglanddegradationinsaarccountries
8. www.ifpri.org
9. web.unep.org
10. www.scielo.br
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