Sustainable Land Management (SLM): An opportunity for multiple agricultural and enviornmental benefits

Dr. Julian Dumanski, Consultant in Sustainable Land Management, Ottawa, Canada

The need for agricultural growth strategies that can achieve the required growth and food security over the next two to three decades, whilst reversing the historical conflict with natural resources conservation, is now a front line issue for global sustainable development. It is widely recognized that agriculture and environmental management are inseparably linked and that tackling problems of natural resource degradation must be seen as part of a wider set of actions to revitalize the rural sector as a whole. Promoting rural development strategies that have "win-win" outcomes for agricultural livelihoods and the environment is mainstream policy for major development agencies, and they are considered vital to provide a sustainable basis for future productivity growth and poverty alleviation.

Agriculture has historically been a major contributor to environmental degradation, but under improved systems of land management, it could be a major partner in the environmental solution. Land management decisions by individual farmers have implications for many environmental goods and services¹, such as impacting on habitats for fauna and flora, on a variety of ecological services, and on amenity or aesthetic values. The impacts may arise directly on land managed for agriculture and livestock, or indirectly as a consequence of fragmentation and degradation of natural (less managed) habitats such as forests and wetlands. These impacts have consequences at local, national, and global levels as shown in the figure below:

 

Biodiversity and Agriculture: Biodiverse² ecosystems have a fundamental role and importance in sustainable development, providing many important benefits. They often contain a variety of economically useful products that can be harvested or serve as inputs for production processes, as well as providing habitats for flora and fauna, and many key ecological services including those associated with nutrient cycling, disturbance regulation, availability and quality of water for agriculture, industry, or human consumption, etc. Agriculture remains dependent on many biological services, such as provision of genes for improved varieties and livestock breeds, but also for crop pollination, soil fertility services provided by microorganisms, and pest control services provided by insects and wildlife. Conversely, sustainably managed agricultural landscapes are important to the conservation and enhancement of biodiversity. The term agrobiodiversity has been coined to describe the important subset of biodiversity that contributes to agriculture.

Climate Change and Agriculture: The linkages between agricultural land use and greenhouse gases relate to land-use dynamics and management of rural landscapes. During the 19th Century, rapid agricultural expansion, primarily in temperate regions, led to widespread clearing of land and losses of organic carbon in vegetation and soils. In recent years, deforestation in temperate regions has been reversed, but land conversions in the tropics has greatly expanded, and this has become a major source of CO2 emissions to the atmosphere (about 1.6 Gt C or about 20% of total anthropogenic CO2 emissions; the continuing net global loss of C from cultivated soils contributes approximately an additional 5% of anthropogenic CO2. Also, agriculture contributes around 50% of anthropogenic CH4 emissions globally, primarily from the rumen of livestock and from flooded rice fields, and about 70% of anthropogenic N2O, largely as a result of nitrogen inputs (synthetic fertilizers and animal wastes, and biological nitrogen fixation).

International Waters and Agriculture: More than 200 river basins are shared by two or more countries, accounting for about 60 percent of the earth's land area. There are at least 54 rivers that cross or form international boundaries in Sub-Saharan Africa, and 10 river basins have drainage areas greater than 350,000 km sq., affecting 33 SSA countries and Egypt.

Many of these shared watercourses are subject to alarming rates of environmental degradation, with strong linkages with land and water management:

• Water withdrawals from lakes and reservoirs, water diversions, upstream dams and lake reclamation for agriculture and aquaculture, significantly deplete the size of the waterbodies, destroying habitats for plants and animals and sometimes causing very high levels of salinization.
   
  
• Deforestation and land degradation in international watersheds such as the Nile, Niger, or Indus affect rainfall patterns, increase the range of local temperatures, and cause major variations in water flow and quality. Soil erosion leads to siltation and sedimentation of lakes and reservoirs, shorten their lifetimes, destroy aquatic environments, reduce the productivity of their ecosystems, and diminish the flood control capacity.

It is recognized that whereas the principles and criteria in sustainable land management systems are universal and transferable, technologies and application must be local. In sustainable agriculture there are no single solutions, short cuts or magic bullets; in fact the magic bullet approach must be consciously avoided³. Blanket recommendations are rarely successful, and innovations found to be successful in one area will likely have to be modified somewhat to be successful in another. For example, zero-till is a successful technology contributing to sustainable land management, but some local modifications of the technology are almost always required for it to be successful. However, the basic principles of zero-till, i.e. minimal disturbance of the soil surface and maintenance of continual soil cover are universal and therefore transferable.

Many of the environmental benefits associated with sustainable land management accrue locally and nationally, such as pollination, biological control, nutrient cycling, soil conservation, etc, as well as a variable proportion of off-site effect such as water regulation and supply, disturbance regulation (e.g. flood control) waste treatment etc. Others are more clearly global, or at least 'supra-national' in scope, such as climate regulation, conservation of genetic resources of potential value in plant breeding or pharmaceuticals, international tourism, and transboundary water-mediated effects.

The global environmental benefits are those for which the global community, through international agreements and nascent trading frameworks, has expressed a willingness to pay for their upkeep, on the grounds that (i) they would normally receive sub-optimal attention within a national accounting and planning framework (ii) they are considered highly valuable, or irreplaceable, or (iii) there is considered to be an unacceptable economic or humanitarian risk associated with further depletion.

It is increasingly recognized that well designed, farmer-centered, sustainable land management interventions have distinct advantages as vehicles for pursuit of joint agriculture-environment objectives. The primary agents of change are the rural communities (farmers, pastoralists) who depend on the land for their livelihoods. Rural families make decisions about production practices and land use in line with their objectives, production possibilities and constraints, but these decisions are part of a wider process to secure and improve the family's food security and livelihood (they are in turn influenced by government policies and market forces). The pillars of sustainable land management are the application of agroecological principles to farming; an emphasis on human resource development and knowledge based management techniques; a participatory and decentralized approach; the value placed of natural and social capital enhancements in addition to economic efficiency gains, and the role of strong and self reliant rural institutions.

Agriculture that is truly sustainable will not be business as usual. It will be a type of agriculture that will provide environmental, economic and social opportunities for the benefit of present and future generations, while maintaining and enhancing the quality of the resources that support agricultural production. This will not be the agriculture of to-day or of the recent past, with an emphasis on maximizing yields and economic returns, but rather one with the objectives of optimizing productivity and conserving the natural resource base. The objective of optimization implies trade-offs in the production systems to ensure maintenance of environmental quality and global, environmental, and life support systems. Experience indicates that these tradeoffs will be defined and implemented voluntarily by farmers and other rural land users, or they will be implemented through policies and legislation. Society is beginning to demand that agriculture become more than simply putting food on the table; it is beginning to demand that it also becomes the steward of rural landscapes.

Footnotes

¹ Also refered to in this paper as biodiversity goods and services. The stock of natural resources from which these goods and services flow is also refered to as 'natural capital'. An important principle is that sustainably managed land constitutes a form of natural capital from which a variety of key services may be derived in the long term.

² Biological diversity, often shortened to biodiversity, embraces the whole of 'Life on Earth'; it encompasses the variability among living organisms from all sources, including terrestrial and aquatic ecosystems and their ecological complexes. This includes diversity within species, among species, and of eco-systems. Decline in biodiversity includes all those changes that have to do with reducing or simplifying biological heterogeneity - from individual members of a species to regional ecosystems.

³ For the extension agent, this means he/she must work more actively in a participatory approach with farmers, and develop an enabling atmosphere for local farmer innovation as to what will work and what is not acceptable. However, providing technological backstopping to the store of local farmer knowledge is often a critical component.

 

 

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