Land provides an environment for agricultural production, but it also is an essential condition for improved environmental management, including source/sink functions for greenhouse gasses, recycling of nutrients, amelioration and filtering of pollutants, and transmission and purification of water as part of the hydrologic cycle. The objective of sustainable land management (SLM)¹ is to harmonise the complimentary goals of providing environmental, economic, and social opportunities for the benefit of present and future generations, while maintaining and enhancing the quality of the land (soil, water and air) resource (Smyth and Dumanski, 1993). Sustainable land management is the use of land to meet changing human needs (agriculture, forestry, conservation), while ensuring long-term socioeconomic and ecological functions of the land.

Sustainable land management is a necessary building block for sustainable agricultural development, and it is a key element in AGENDA 21's goal of sustainable development (Chapter 10). Sustainable agricultural development, conservation of natural resources, and promoting sustainable land management are key objectives of the new World Bank rural investment program, From Vision to Action (World Bank, 1997), and increasingly these objectives are being included in all agricultural development and natural resources management projects.

Sustainable land management combines technologies, policies, and activities aimed at integrating socioeconomic principles with environmental concerns, so as to simultaneously:

• maintain and enhance production (productivity)
  
• reduce the level of production risk, and enhance soil capacity to buffer against degradation processes (stability/resilience)
  
• protect the potential of natural resources and prevent degradation of soil and water quality (protection)
  
• be economically viable (viability)
  
• be socially acceptable, and assure access to the benefits from improved land management (acceptability/equity)

The definition and these criteria, called pillars of SLM, are the basic principles and the foundation on which sustainable land management is being developed. Any evaluation of the sustainability has to be based on these objectives: productivity, stability/resilience, protection, viability, and acceptability/equity (Smyth and Dumanski, 1993). The definition and pillars have been field tested in several countries, and they were judged to provide useful guidance to assess sustainability.

The lack of a comprehensive, quantifiable definition for sustainable land management is sometimes considered to be a serious deficiency. Yet, as argued by Gallopin (1995), a research model for sustainability has to be more flexible and therefore less easy to quantify than a research model for chemistry, physics, or classical agronomy. Such a research model must be designed around an evaluation process (rather than thematic context), because it is intended to test the likelihood of certain events taking place and the aggregate impacts of these events, rather than specifics of various null hypothesis or the impacts of certain inputs or land management interventions. Essentially the research model must include a goal statement, a conceptual framework, a set of procedures, and criteria (indicators) for diagnosis. One of the main objectives of such a research model is to evaluate the impacts of events which are uncertain, but the process of evaluation is guided by scientifically defined protocols.

PRINCIPLES AND CRITERIA FOR SUSTAINABLE LAND MANAGEMENT

Experiences gained from field projects in developing and developed countries has identified a series of principles (lessons learned) for sustainable land management, and these can be used as general guidelines for development projects (Dumanski, 1994; 1997; World Bank, 1997). The most useful of these are summarised below:

Global concerns for sustainability

• Sustainability can be achieved only through the collective efforts of those immediately responsible for managing resources. This requires a policy environment that empowers farmers and other, local decision makers, to reap benefits for good land use decisions, but also to be held responsible for inappropriate land uses.
  
• Integration of economic and environmental interests in a comprehensive manner is necessary to achieve the objectives of sustainable land management. This requires that environmental concerns be given equal importance to economic performance in evaluating the impacts of development projects, and that reliable indicators of environmental performance be developed.
  
• There is urgent need to resolve the global challenge to produce more food to feed rapidly rising global populations, while at the same time preserving the biological production potential, resilience, and environmental maintenance systems of the land. Sustainable land management, if properly designed and implemented, will ensure that agriculture becomes a part of the environmental solution, rather than remaining an environmental problem.

Sustainable Agriculture

• More ecologically balanced land management can achieve both economic and environmental benefits, and this must be the foundation (linch pin) for further rural interventions (investments). Without good land management, other investments in the rural sector are likely to be disappointing². At the same time, arguing for the continued maintenance of agriculture without reference to environmental sustainability is increasingly difficult. Indicators of land quality are needed to guide us along the way.
  
• Agricultural intensification is often necessary to achieve more sustainable systems. This requires shifts to higher value production, or higher yields with more inputs per unit of production and higher standards of management (more knowledge intensive). However, sustainable agriculture has to work within the bounds of nature not against them. Many yield improvements can be achieved by optimizing efficiency of external inputs rather than trying to maximize yields.
  
• The importance of off-farm income should not be underestimated because it i) supplements cash flow on the farm, ii) generates an investment environment for improved land management, and therefore iii) reduce production pressures on land.

Sharing responsibilities for sustainability

• Farmers and land managers must expand their knowledge of sustainable technologies and implement improved procedures of land stewardship. The preferred option is not to tell the farmer what to do (command and control legislation), but to create an enabling environment through policy interventions where farmers are more free to make the right choice. A policy environment where farmers are more empowered, but also held accountable, for achieving the objectives of sustainable land management is essential. However, sustainable land management is the responsibility of all segments of society. Governments must ensure that their policies and programs do not create negative environmental impacts, and society needs to define requirements for land maintenance and develop a "social" discount rate for future land use options that encourages the most sustainable use.
  
• Concerns for sustainable land management go beyond agriculture to include the legitimate interests of other aspects of land stewardship, including wildlife, waterfowl and biodiversity management. There is increasing evidence that society is demanding that farmers become stewards of rural landscapes, and that agriculture become more than simply putting food on the table. Many of society's environmental values may not represent economic gains for farmers, however, and farmers cannot shoulder all the costs of environmental maintenance.

RELATIONSHIPS AMONG SOIL QUALITY, LAND QUALITY, AND SUSTAINABLE LAND MANAGEMENT

New concepts of soil and land quality³ are emerging, and often these are used interchangeably. These concepts and their relationships are summarized below, to the extent that some concensus is available on how these should be applied:

Soil quality is the capacity of a specific soil to function within natural or managed ecosystem boundaries to sustain plant and animal production, maintain or enhance water quality, and support human health and habitation (SSSA, 1994).

Land quality is the condition, state or "health" of the land relative to human requirements, including agricultural production, forestry, conservation, and environmental management (Pieri, et al., 1995).

Sustainable land management combines technologies, policies, and activities aimed at integrating socio-economic principles with environmental concerns so as to simultaneously maintain or enhance production, reduce the level of production risk, protect the potential of natural resources and prevent (buffer against) soil and water degradation, be economically viable, and be socially acceptable (Smyth and Dumanski, 1993).

These concepts span the scales of detail, application, and levels of integration with socio-economic data. Soil quality is the most restrictive, followed by land quality and then sustainable land management. Soil quality is effectively a condition of a site, and it can be studied using soil data alone. Land quality requires integration of soil data with other biophysical information, such as climate, geology and land use. Land quality is a condition of the landscape, i.e. it is a biophysical property, but includes the impacts of human interventions (land use) on the landscape. Sustainable land management requires the integration of these biophysical conditions, i.e. land quality, with economic and social demands. It is an assessment of the impacts of human habitation, and a condition of sustainable development.

These are more than simple differences in semantics; the concepts differ in the kinds and scale of the processes being described, the data used for input, and the amount and kinds of integration with other disciplines (Dumanski, et al., 1997). However, the concepts form a continuum over the landscape, and they must be applied for different types and scales of land use.

THE LAND QUALITY INDICATOR (LQI) PROGRAM

Assessment of sustainable land management requires appropriate evaluation instruments, such as Land Quality Indicators. However, land quality, like the concept of sustainable land management of which it is a part, requires operational definitions and specific, measureable indicators if it is to be more than an attractive, conceptual phrase.

The World Bank, in collaboration with UNEP, UNDP, FAO and the CGIAR, is developing a program called Land Quality Indicators (LQIs), as a means to better coordinate actions on land related issues such as land degradation (Pieri, et al., 1995). In the area of economic and social data, and in some cases for air and water quality, indicators are already in regular use to support decision-making at global, national and sub-national levels. In contrast, few such indicators are available to assess, monitor and evaluate changes in the quality of land resources. Land refers not just to soil but to the combined resources of terrain, water, soil and biotic resources that provide the basis for land use. Land quality refers to the condition or "health" of land, and specifically to its capacity for sustainable land use and environmental management.

The LQI program addresses the dual objectives of environmental monitoring as well as sector performance monitoring for managed ecosystems (agriculture, forestry, conservation and environmental management). It is being developed for application at national and regional scales, but it is also part of a larger, global effort on improved natural resources management. The LQI program is in response to the United Nations Conference on Environment and Development, and it fits with Agenda 21 expectations as well as the Convention to Combat Desertification.

Agricultural cropland, including agroforestry, as well as forested lands, range and pasture lands, are under increasing pressure because of population migrations to marginal land areas and agricultural intensification on existing cultivated lands. Sustainable land use intensification requires the maintenance or enhancement of the productive potential of the land resources, i.e. increases in food supplies must come from agricultural intensification rather than from area expansion, but this must be done without degrading the land resource on which production depends. The question is how this should be achieved, and how to monitor progress towards this objective in the different agroecological regions of developing countries. LQIs are tools to help us along the way.

In general and particularly in developing countries, it is essential that scarce resources devoted to land management be used more cost-efficiently and that policy-makers have at least rough indicators of whether environmental conditions and land quality are getting better or worse. Land quality indicators, such as nutrient balance, loss of organic matter, land use intensity and diversity, and land cover are useful to task managers and decision makers to monitor and improve the performance of projects with respect to their socio-economic and environmental impacts, and to assess the trend towards or away from land use sustainability. While routine project performance indicators based on cost-benefit analyses (input-output factors, risk and economic performance indicators), are necessary to monitor the activities and components of a project, LQIs are required to evaluate the environmental impact(s). The quantitative assessment of physical impacts, such as depletion of soil nutrients, loss of organic matter, soil erosion, water contamination etc. may appear to be costly and cumbersome during project implementation, but the long-term negative impact of reduced land quality, such as decreased efficiency of fertilizers, increased erosion, increased fuel consumption, increased pest infestation (nematodes, etc.), often result in rehabilitation costs that are much higher. The LQI approach focuses on preventive maintenance rather than rehabilitation, and provides the methodology and the approach to integrate the socio-economic and biophysical information that are required for better informed sustainable land management strategies.

The development of LQIs follows a logical framework, providing information not only on the state of the resources, but also the underlying causes (or "pressure") as well as the response of the society to the state and the pressure exerted on the land resources. Because of the nature and the complexity of land issues, the LQI program recommends addressing issues of land management by agro-ecological zones (Resource Management Domains⁴ or "Terroirs"). This new approach puts the focus on evaluating impacts of human interventions on specific landscapes, rather than emphasizing only biophysical variables as was the case in the past. At the same time, this spatial stratification favors incorporating farmer and other local knowledge into the overall process of improved agricultural and environmental land management.

A research strategy for the Land Quality Program was developed during a two day research planning meeting, Washington, D.C., 1996, sponsored by the World Bank. A panel of internationally acclaimed scientists and administrators established the objectives and priorities for the research, defined strategic alliances to be developed with ongoing national and international programs, and identified potential sources of funding. They also achieved international agreement on a core set of strategic land quality indicators.

Core LQIs for managed ecosystems (agriculture and forestry) in the major agro-ecological zones (AEZs) of tropical, sub-tropical and temperate environments, and recommended for development in the short term include:

• Nutrient balance. this describes nutrient stocks and flows as related to different land management systems used by farmers in specific AEZs and specific countries
  
• Yield trends and yield gaps. this describes current yields, yield trends, and actual:potential, farm level yields for the major food crops in different countries
  
• Land use intensity. describes the impacts of agricultural intensification on land quality. Intensification may involve increased cropping, more value-added production, and increased amounts and frequency of inputs; emphasis is on the management practices adopted by farmers in the transition to intensification.
  
• Land use diversity (agro-diversity). describes the degree of diversification of production systems over the landscape, including livestock and agro-forestry systems; it reflects the degree of flexibility (and resilience) of regional farming systems, and their capacity to absorb shocks and respond to opportunities.
  
• Land cover. describes the extent, duration and timing of vegetative cover on the land during major erosive periods of the year. It is a surrogate for erosion, and along with land use intensity and diversity, it will give increased understanding on the issues of desertification.

A second set of core LQIs were recommended for longer-term research. These are indicators which require further development of their theoretical base, or lack adequate data for immediate development⁵. These include:

• Soil Quality. likely to be based on soil organic matter turn-over, particularly the dynamic (microbiological) carbon pool most affected by environmental conditions and land use change.
  
• Land degradation (erosion, salinization, compaction, organic matter loss): these processes have been much researched and have a strong scientific base, but reliable data on extent and impacts are often lacking.
  
• Agro-biodiversity. involves objectives of managing natural habitats and the co-existence of native species in agricultural areas, maintaining natural soil micro and meso biodiversity, and managing the gene pools utilized in crop and animal production.

Four additional sets of core LQIs were identified, but these were recommended to be developed through collaboration with the respective authoritative disciplines:

• Water quality
  
• Forest land quality
  
• Rangeland quality
  
• Land contamination/pollution

The above are the biophysical components of sustainable land management. Although useful in their own right, they must still be complemented with indicators of the other pillars of sustainable land management, economic viability, system resilience, and social equity and acceptability. Considerable additional work is required to develop these pillars to the same level of detail as the land quality (biophysical) indicators.

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¹ The concept of sustainable land management (SLM) grew out of a workshop in Chiang Rai, Thailand, 1991. This workshop recommended forming an international working group of the International Society of Soil Science (ISSS) to refine the concept, develop a definition, and to recommend a procedure to monitor and evaluate our progress towards sustainable land use systems. A second workshop (Lethbridge, Canada, 1993), emphasized development of indicators of sustainable land management as instruments for monitoring and evaluation. The results of these experiences were brought together at the XVth Congress of Soil Science, Acapulco, 1994. Subsequent international workshops (Cali, Colombia, 1995; Nairobi, Kenya, 1995; Washington, D.C., 1996, Naurod, Germany, 1997) focused on indicators of land quality as part of the suite of required SLM indicators. A third workshop (Enschede, 1997), set the stage for the "next steps" in the development and application of sustainable land management.

2 Sustainable land management requires a long-term commitment on maintaining the quality of the land resource; unfortunately, short-term economics often promote technologies that exploit and degrade the land.

3 These concepts of "quality" are based on the essential characteristics of soil and land to fulfill human land use requirements, for example, agriculture, forestry, conservation and maintenance of environmental functions. Natural land quality comes from the suitability of land for specified uses, and is not uniform over the landscape; human interventions (land management) can degrade or enhance land quality; changes in land quality are assessed in relation to benchmarks, such as changes from an undisturbed state.

4 The following definition of Resource Management Domains was developed at an international workshop held in Kuala Lumpur, August 21 - 25, 1996: "A Resource Management Domain is a spatial (landscape) unit for identification and application of resource management options to address specific issues. It is derived from geo-referenced biophysical and socio-economic information, and it is dynamic and multiscale in that it reflects human interventions in the landscape".

5 Only general indicator themes (rather than specific indicators) have been identified so far, along with some preliminary criteria.

REFERENCES

Dumanski, J. 1994. International Workshop on Sustainable Land Management for the 21st Century: Summary. Workshop Proceedings. Agricultural Institute of Canada, Ottawa, ON. 50 pp.

Pieri, C., Dumanski, J., Hamblin, A., and Young, A. 1995. Land Quality Indicators. World Bank Discussion Paper No.315. World Bank, Washington, DC. 51 pages.

Smyth, A.J. and Dumanski, J. 1993. FESLM: An international framework for evaluating sustainable land management. A discussion paper. World Soil Resources Report 73. Food & Agriculture Organization, Rome, Italy. 74 pp.

World Bank. 1997. Rural Development. From Vision to Action. ESSD Studies and Monographs Series 12. World Bank, Washington, DC. pp 157.