"Sustainable development is pro-people, pro-jobs and pro-nature" Human Development Report 1994.	In the long term, increasing food production depends on using natural resources sustainably, not destroying them.

Five root causes of unsustainable practices

There are five root causes of unsustainable agricultural practices and degradation of the rural environment:

Policy failure

Leading among the causes of unsustainable agriculture are inadequate or inappropriate policies which include pricing, subsidy and tax policies which have encouraged the excessive, and often uneconomic, use of inputs such as fertilizers and pesticides, and the overexploitation of land. They may also include policies that favour farming systems which are inappropriate both to the circumstances of the farming community and available resources.

Rural inequalities

Rural people often know best how to conserve their environment, but they may need to overexploit resources in order to survive. Meanwhile commercial exploitation by large landowners and companies often causes environmental degradation in pursuit of higher profits.

Resource imbalances

Almost all of the future growth in the world's population will be in developing countries and the biggest increases will be in the poorest countries of all, those least equipped to meet their own needs or invest in the future.

Unsustainable technologies

New technologies have boosted agricultural production worldwide, but some have had harmful side effects which must be contained and reversed, such as resistance of insects to pesticides, land degradation through wind or water erosion, nutrient depletion or poor irrigation management and the loss of biological diversity.

Trade relations

As the value of raw materials exported by developing countries has fallen, their governments have sought to boost income by expansion of crop production and timber sales that have damaged the environment.

Most of the 20 million square kilometres of the world's drylands - which support 500 million people are subject to degradation; some 60 000 square kilometres of land are lost each year. The main strategies for sustainable agriculture and rural development must be to create employment locally and to find alternatives to practices which overexploit the land. Low-cost soil and water conservation measures are needed, while the pressure on fuelwood can be reduced by tapping other local sources of energy, such as wind and biogas. Planting legume-based crops and trees, which fix their own nitrogen, can reverse the depletion of soil nutrients and reduce the need for mineral fertilizers.

Overgrazing can be reduced by encouraging greater control over the use of resources and increasing the offtake of livestock by improving market networks. The reduction or removal of subsidies and other actions that reduce the cost of maintaining livestock can also encourage greater offtake. Growing hay, development of leguminous forage and the promotion of species of trees and shrubs that are productive during the dry season can provide alternative sources of feed and alleviate shortages.

About 35 percent of all irrigated land - the major source of cereals and export crops - is at risk of salinization because of poor management. Efficient use of water can be promoted by local farmers participating in drainage and irrigation design, improved training and water pricing policies that curb excessive use. Small-scale schemes planned and implemented by local institutions can reduce many irrigation problems if backed by national policies that effectively support appropriate technologies, credit, marketing, energy supplies and maintenance of equipment.

Humid and semi-humid forests support 1 000 million people and are the world's largest biomass reservoir, but their sustainability is threatened by the removal of trees and the degradation of watersheds. Most of this is caused by clearing for agriculture, which is unsustainable either because the fertility of the soil is low or because the methods of cultivation are unsuitable.

To meet the needs of their increasing populations, most developing countries will need to convert some of their forest areas for agricultural use, but this needs to be done on the basis of land use planning that ensures that it is sustainable.

The pace of deforestation will be slowed only by ensuring that the conservation and management of forest resources are more attractive to local people than their destruction, and that commercial interests use forest land in a sound, sustainable way.

Options to help achieve this include agroforestry involving food crops and trees; the sustainable harvesting of non-wood forest products; and sustainable forest management and timber harvesting.

The world's highlands cover 10 million square kilometres, and serve as watersheds for far more. In Asia, for example, some 9 million square kilometres of downstream land is at risk of flooding as a result of highland degradation. The central objectives must be to raise farm productivity using low-cost technologies, and to reduce population pressure. Policies that promote employment in agriculture and opportunities for income outside it are recommended. Perennial tree and shrub crops, and mixing crops and livestock, provide sustainable alternatives to shifting agriculture and produce higher incomes from far less land.

Sustainable forest management and agroforestry provide fodder, fuelwood and timber, and reduce erosion. Moderate slopes should be reserved for horticultural and fodder crops, steep ones for tree crops - possibly through incentives and regulations. Overgrazing can be countered by selling more livestock, sterilization and culling, and controlling livestock by stall feeding. Improved breeds and animal health will raise productivity, even with fewer animals.

As these areas often have poor access, their management relies on local initiatives, but these must be complemented by development of roads, hydropower schemes, and better credit and marketing.

Proposals for progress

FAO proposes a choice of four key strategies to attain sustainable agriculture and rural development. The first two promote intensification; the third and fourth are applicable when limits on natural resources or environmental or socio-economic constraints make this unsustainable.

Intensification through specialization
This is mainly suited to land with high crop potential. It depends on the judicious use of external inputs such as pesticides and fertilizers combined with improved agricultural and related practices. The introduction of improved soil management, integrated pest management and efficient waste management all promote sustainability.

Intensification through diversification
This is suited to a wider range of conditions. Mixed cropping systems, plus improved management techniques, help promote maximum efficienty in natural resource use. Diversification can minimize environmental and socio-economic risks, assist waste recycling and reduce the need for external inputs.

Combining on-farm and off-farm activities
Promoting additional sources of income can limit pressure on natural resources.

Extensive systems
Suited to marginal areas, or ones with low agricultural potential, they can either be specialized (as in ranching) or diversified (as in shifting cultivation). Few external inputs are used, so integrated pest management, water management, and the conservation and maintenance of soil fertility are particularly important. The sustainability of these systems depends on having low population densities and only light pressure on natural resources.

Three objectives should guide the choice between these options:

• improving efficiency in the use of resources and inputs;
• increasing the resilience of agriculture and producers to adverse socio-economic and environmental conditions;
• promoting diversity, through varied farming systems that help spread the farmer's risks or the use of areas for other purposes. such as forestry.

The Den Bosch declaration

In April 1991, FAO held a conference on agriculture and the environment, with the cooperation of the Netherlands Government, attended by senior government officials and experts from some 120 countries. It adopted the Den Bosch Declaration calling for "fundamental changes" in development policies and strategies so as to meet the world's increasing need for food without degrading the environment. These changes included:

• the participation of rural people in the research and development of systems for more efficient management of the natural resources available to the farmer;
• devolving the responsibility and authority for decision making to the local level, rather than relying on top down" administration;
• allocating clear and fair legal rights and obligations on the use of land and other natural resources, including land reforms as necessary;
• investing in improving, rehabilitating and conserving natural resources;
• adjusting economic and agricultural policies and instruments to promote production systems and technologies that can help attain sustainability;
• encouraging demand and providing incentives that favour crops and animals that can be produced and processed sustainably;
• promoting practices, production and processing systems that pay particular attention to safeguarding health and the quality of the environment;
• promoting opportunities in rural areas to earn livelihoods off the farm.