This study had its origins in collaborative efforts by the countries of South Asia, aware of the increasing problem of land degradation and seeking to assess its magnitude and effects. Work was carried out by means of FAO/UNEP/UNDP Inter-country Project RAS/92/560/A, Study of Land Degradation in South Asia. This report was compiled and written by Anthony Young. Detailed data were contributed by J.S.P. Yadav. The work owes much to advice received from Frank J. Dent, Regional Soil Management and Fertilizer Use Officer, RAPA. Thanks are offered for the kind cooperation of staff of the many institutions visited, including international organizations, regional organizations in Asia, and, in particular, institutions in countries of the region. Additional case study material is contained in a consultant's report by Yadav (1993).
INTRODUCTION
Origin and objectives
This study originated in Resolution Number 1991/97 of the Economic and Social Council of the United Nations, passed at its 32nd plenary meeting on 26 July 1991, entitled:
Combating aridity, soil erosion, salinity, waterlogging, desertification and the effects of drought in South Asia.
The Resolution calls for a study to assess the extent of the problem of land degradation and its effects on the peoples of the region, to provide a framework for national and international cooperative efforts to tackle this problem in its physical and human dimensions. The work was carried out by means of a joint FAO/UNEP/UNDP project.
The immediate objective of the project was to undertake a comprehensive study on land degradation in South Asia and its effects upon the people. This specific objectives indicate the aspects covered in this report:
South Asia region
The South Asia region, as covered in this report, comprises eight countries. For purposes of regional comparison they are grouped into two zones, with India divided into a dry, western region and a humid region (Figure 1, p. 14):
| Dry zone | Humid zone |
| Afghanistan | Bangladesh |
| India, dry region | Bhutan |
| Iran | India, humid region |
| Pakistan | Nepal |
| Sri Lanka |
The region has a land area of 641 M ha and a population (1990) of 1200 million. The agricultural population is 768 million, 61 % of the total. The area of cropland is 227 M ha, of pasture 94 M ha, and thus of cropland and pasture together, termed agricultural land, 321 M ha. These statistics indicate two basic characteristics of the region, which are fundamental to the problems being considered:
TYPES OF LAND DEGRADATION
Definitions
The term land refers not just to soil, but to all natural resources which contribute to agricultural production. Land degradation is the temporary or permanent lowering of the productive capacity of land. Three degrees of severity of degradation are recognized:
Light: somewhat reduced agricultural
productivity;
Moderate: greatly reduced agricultural productivity;
Strong: not capable of agricultural production, and unreclaimable
at farm lever.
Desertification is defined by UNEP as land degradation in aria, semi-arid and dry subhumid areas resulting from adverse human impact. In this report, therefore, it is equivalent to land degradation in the dry zone.
Types of land degradation
The following types of land degradation are assessed:
Three other types are considered in more generalized terms:
Soil pollution, urban encroachment onto agricultural land, and the potential effects of global climatic change, whilst well recognized as actual or potential problems, have not been assessed in this study.
Reversible degradation and land reclamation
The effects of water and wind erosion are largely irreversible. Although plant nutrients and soil organic master may be restored, to replace the actual loss of soil material would require taking the soil out of use for many thousand of years, an impractical course of action.
In other cases, land degradation is reversible: soils with reduced organic master can be restored by additions of plant residues, degraded pastures may recover under improved range management. Salinized soils can be restored to productive use, although at a high cost, through salinity control and reclamation projects.
The cost of reclamation, or restoration to productive use, of degraded soils is normally much higher than the cost of preventing degradation before it has occurred.
SOURCE OF DATA
The major source of data employed is the Global assessment of soil degradation (GLASOD). Other sources are material assembled by the Asian Problem Soils Network, and estimates by individual countries. The GLASOD estimates are taken as the primary basis for this report, modified where the balance of evidence suggested a need to do sot For deforestation, data are taken from the FAO Forest resources assessment 1990 project.
The available data on the extent and severity of degradation are highly variable. Reasons are first, a failure to define in sufficiently precise terms what is meant by the various degrees of severity of degradation; and secondly, the absence of reliable surveys over large areas.
STATUS OF LAND DEGRADATION
Best estimates from an assessment of the statue of land degradation are given in detail in Table 18 (p. 50). Combining the degrees of severity, and giving totals for the dry zone, the humid zone, and the South Asian region, summary data are shown in Table 19 (p. 52).
Water erosion is the most widespread form of degradation, affecting some 25% of agricultural land. It is found widely in both the dry and humid zones. In many areas of sloping land, for example in Nepal, it has reached severe proportions, causing or threatening the permanent loss of the productive capacity of land.
Wind erosion is estimated to affect of the order of 40% of agricultural land in the dry zone, although quantitative evidence for definition of its degrees of severity is lacking.
Soil fertility decline, formerly not as widely recognized as other types of degradation, is a substantial and widespread problem in the region. It occurs through a combination of lowering of soil organic master and loss of nutrients. Evidence for fertility decline includes data on:
Waterlogging affects some irrigated lands on the alluvial plains and interior basins. Whilst less extensive than other types of degradation on a regional scale, it is severe in some areas.
Salinization (including codification) is a severe problem on irrigated lands of the dry zone. It is found both in light to moderate degrees, reducing crop yield, and in the severe degree, causing complete abandonment of formerly productive irrigated land. Salinization through intrusion of salt water is also found in coastal areas.
Lowering of the groundwater table has occurred in certain irrigated areas where the groundwater remains non-saline.
Although waterlogging, salinization and lowering of the water table are of smaller extent than other types of degradation , their consequences are proportionally greater, since they mainly affect irrigated lands which are potentially the most productive.
A summary of the severity of land degradation with respect to the countries of the region, including the above six types together with deforestation and rangeland degradation is given in Table 22 (p. 90).
The countries of the dry zone - Afghanistan, Iran, Pakistan and the western part of India - are severely affected by water and wind erosion, soil fertility decline, deforestation and rangeland degradation. Their alluvial plain and basin areas are affected by waterlogging, salinization and lowering of the water table. By definition, therefore, these countries are severely affected by desertification.
Four countries of the humid zone - Bangladesh, Nepal, Sri Lanka and the greater part of India - are severely affected by water erosion on their rainfed lands, by soil fertility decline, and by deforestation. In parts of the hill and mountain areas of Nepal, deforestation and water erosion have reached an extreme degree. Bhutan, because of its longer population density, has not yet suffered severe land degradation, but deforestation, often the first set leading towards degradation, is taking place.
The problem of soil fertility decline has not previously received sufficient attention. On a national scale, increases in crop yields are falling behind rates of increase in fertilizer use. Surveys have shown that soil organic master levers are falling. Micronutrient deficiencies are being widely reported, where farmers have attempted to sustain yields by application of major nutrients only. In long-term experiments, yield responses are declining except where fertilizer is applied in conjunction with organic manure. This form of degradation is found in both the humid and dry zones. Whilst its widespread occurrence is not in doubt, quantitative estimates of its extent and severity will require further surveys and monitoring of soil changes.
CAUSES OF DEGRADATION
Natural de gradation hazards , direct causes and underlying causes
Land degradation results from cultural degradation hazards, direct causes, and underlying causes.
Natural degradation hazards are conditions of the natural environment which lead to high susceptibility to degradation, for example steep slopes, rains of high intensity, strong leaching in humid regions, and drought in dry regions.
Direct causes of degradation are unsuitable land use and inappropriate land management practices. These vary with the type of degradation. They include:
Underlying causes of degradation are the basic reasons which give rise to the direct causes. These are:
The causal nexus between land, population and degradation
The direct and indirect causes of land degradation are linked by a causal nexus (Figure 9, p. 62). The two external, or driving, forces are limited land resources and increase in rural population. These combine to produce land shortage, resulting in small farms, low production per person and increasing landlessness. A consequence of land shortage is poverty.
Land shortage and poverty, taken together, lead to non-sustainable land management practices, the direct causes of degradation. This has the effect of increasing land shortage, a vicious cycle of cause and effect. "It is population growth working in conjunction with other factors that is bringing about widespread environmental deterioration" (FAO/RAPA, 1990, p. 10) "...environmental degradation perpetuates poverty, as the poorest groups attempt to survive on a diminishing resource base" (FAO, 1992, p. 106).
There are two ways to intervene in this nexus: improved technology and reduction of population increase. Increased efforts should certainly be made in research into improved technologies especially their more widespread implementation. However, it must be emphasized that all efforts allmproved technology will be nullified and in places reversed unless they are accompanied by a reduction in the rate of growth of population. A much greater integration between population policy, agriculture, and land resource management is needed.
For this to occur, new attitudes are required. There is growing recognition of the need to link population policy with development. "Population issues currently encompass areas of concern such as poverty alleviation, environmental degradation ... which are much broader than population size and growth alone" (ESCAP, 1991, para. 529). "Few institutions have developed a response strategy to the implications of population pressure on natural resource management (Asian Development Bank, 1991, p. 21). "The close link between poverty and environmental problems make a compelling case of increasing assistance to reduce poverty and slow population growth" (World Bank, 1992). A much "rater integration between population policy and agriculture and land resource management is needed.
ECONOMIC CONSEQUENCES OF DEGRADATION
The economic cost of degradation
An attempt has been made to estimate the economic cost of land degradation. Many of the critical assumptions are based on tentative data, particularly the relative production loss resulting from different degrees of degradation. The results are therefore provisional, and refer to orders of magnitude of the macroeconomic effects.
The estimates are based primarily on the measurement of two variables: production loss and replacement cost. Production loss is the reduced productivity of the soil as a consequence of degradation, expressed as a percentage of production from the undegraded soil. For erosion and soil fertility decline, the assumptions are a 5-10% production loss for a light degree of degradation, 20% for moderate and 75% for strong degradation, for the case of salinity, the respective losses assumed, based on experimental data, are 15, 65 and 100% respectively. Replacement cost is the cost of additional inputs (primarily fertilizer) used by farmers in order to maintain production levers on the degraded soils. Price assumptions are US$200 per tonne for cereals and US$300 per tonne of fertilizer nutrients.
Summing the estimates for the direct on-site costs of land degradation shown in Table 21 (p. 75) gives a total of US$9.8 - US$11.0 thousand million per year. Thus, in round figures, the cumulative effect of human-induced land degradation is estimated to cost countries of the region a sum on the order of US$ 10 thousand million per year. Addition of the off-site effects of erosion would substantially increase this figure.
The on-site cost is equivalent to 2% of the gross domestic product of the region, or 7% of its agricultural gross domestic product. The inclusion of off-site effects of water erosion would substantially increases this value.
Discussion
A 'contrary' view exists, which stases:
"Estimates of the extent of land degradation, or of their effects on production, may be considerably exaggerated. Unless and until there is a better foundation of evidence, the problem does not meet the criteria for development investment."
This view serves one important purpose, in that it places emphasis on what are, indeed, large uncertainties in estimates of the extent of degradation and its effects.
Although some of the estimates are based on questionable foundations, reports from all countries of the region point to the certain existence of two kinds of situation:
It is therefore concluded that, although more precise data should be obtained, the total evidence is sufficient to call for immediate action to prevent further land degradation and, where possible, to reverse the effects of past degradation.
EFFECTS UPON THE PEOPLE
The effects of land degradation may be grouped as effects upon production and consequences for the people.
The effects upon production are:
The consequences for the people are:
Land degradation has its most serious effects upon the poor. Poor farmers, primarily those with small landholdings, have neither the resources to combat land degradation nor the options to meet short-term disasters, such as flood, drought, attack by pests, or war. It is the poor who, by force of circumstances, suffer most from the nexus of land, population, poverty and degradation.
INSTITUTIONS AND PROGRAMMES TO COMBAT DEGRADATION
National institutions
Institutional structures to combat land degradation may be grouped into institutions responsible for strategy and policy, research, and implementation.
Bangladesh, India, and Pakistan possess large and complex institutional structures for these purposes. Other countries in the region have structures which are smaller but still (with the exception of Bhutan) moderately complex. The operation of institutions in Afghanistan is seriously hindered by current political conditions.
Whilst most institutional questions are specific to countries, two features are commonly found:
The subject of land resources should become recognized as a major division of environmental affairs. Land resources cover the sustainable use of the resources of climate, water, soils, landform and vegetation, combining productive use with conservation. Countries should seek to clarify institutional responsibilities in the area of land resources.
Environmental legislation
It is recognized that improvements in environmental legislation have a role to play in combating land degradation. It has not been possible, however, to include a review of such legislation in this study.
Regional collaborative programmes
The fight against land degradation has received support from regional collaborative programmes, in particular:
These networks continue to play an important role in exchange of ideas and formulation of policy and programmes.
PROPOSALS FOR ACTION
Introduction
If integrated action is not taken to combat both the direct and the indirect causes of land degradation:
A prerequisite for effective action is recognition, by national governments, of the severity of land degradation and its effects upon people. It is not sufficient to pay lip service to 'environment' nor to write reports. There must be allocation of staff, budget and resources.
Proposals for action
Seven proposals are made, for action to strengthen efforts to combat land degradation. They are confined to the main fines of approach and action. Many of the proposed actions will initially require discussion on a regional, and in some cases global, basis, in order to secure uniformity of methods. They will subsequently require modifications in detail to meet the circumstances of different countries.
- survey of the present state of degradation;
- monitoring of soil changes.
- Clarify institutional responsibilities. It may be necessary to establish high-level advisory committees on land degradation policy.
- Identify nodal institutions for land degradation.
- Identify priorities, with respect to types of degradation and critical areas.
- Plan and carry out national programmes.
- practical methods of improving and maintaining soil organic master statue;
- ways of securing participation of the people in the implementation of improved measures of land management, for example soil conservation measures which provide intrinsic incentives for the land users;
- research into the underlying causes of degradation, and the integration of land resources management with wider aspects of population policy.
- watershed management and soil conservation projects and extension work;
- method for improving soil organic master statue; application of integrated plant nutrition systems; - salinity control and reclamation projects;
- reafforestation;
- further development of agroforestry, including for soil conservation;
- control of desertification, including sand dune fixation, and improved rangeland management.
Attempts to combat land degradation directly, by conservation measures or land reclamation, can have only short-term effects unless they are accompanied by efforts to tackle the underlying causes. These lie in the causal nexus between population increase, limited land resources, land shortage, poverty, non-sustainable land management practices, and land degradation. In the prevailing situation in which there is no spare land available, population increases of 2-3% per year will largely or entirely counteract the effects of measures for improvement.
Population is a sensitive issue, but all governments of the region are aware of the problems caused by continued increase at present rates. In the context of land degradation, a much greater integration between population policy, agriculture and land resource management is needed. For this to occur, new attitudes will be required.