Focus On Planet Earth - AFRICA LAND.

SOUTH AMERICA ECOSYSTEMS LAND

The major land-related problems in the region are erosion; soil contamination resulting from industrial and agricultural activities, including the overuse of fertilizer and pesticide use; and water contamination from agricultural practices.

Canada depends on the land for its economic well-being more than most other industrialized nations. One in three workers is employed directly or indirectly in agriculture, forestry, mining, energy generation, and other land-based activities (Government of Canada, 1996). In the United States, while dependence on primary production is lower, agricultural production and marketing account for 16 per cent of employment, and almost half of the total land area (excluding Alaska) is dedicated to agriculturally related purposes (PCSD, 1996).

U.S. agriculture is in transition. While total cropland has stayed nearly constant since 1945 at 186 million hectares, much of the best farmland is adjacent to major metropolitan areas and is being converted to non-agricultural uses (PCSD, 1996; USDA, 1996). The number of farms declined by almost 31 per cent, from 2.9 million in 1970 to 2 million in 1994, as the average size of farms increased by about 28 per cent in the same period (PCSD, 1996). New strategies are needed to address the changing situation.

Throughout North America, then, the management of farms and rangeland is a key part of sustainable development. Poor agricultural practices result in hazards to human health. Although the pesticide DDT has been banned in Canada and the United States, residues of DDT, such as DDE, are still found in the serum and fat tissues of the majority of North Americans due to its persistence in the environment and to continued inputs from other regions through long-range transport. High DDE levels in women have been associated with an increased risk of breast cancer. The presence of other chlorinated compounds in human tissues has raised concerns about their possible harmful effects on endocrine and reproductive functions (Pohl and Chivian, 1996; Canadian Dept. of Foreign Affairs and International Trade, 1996b).

Some measures are being taken to address key problems. For example, by 1992, U.S. farmers had reduced soil erosion on croplands by around one billion metric tons per year from 1982 levels (NSTC, 1996).Soil erosion savings have come about through the Conservation Reserve Program (635 million metric tons), conservation technical assistance (272 million metric tons), and conservation compliance (90 million metric tons) (PCSD, 1996).

To mitigate the use of persistent organic pollutants (POPs), Canada and the U.S. have developed and implemented pesticide management programmes nationally and regionally.

United Nations Environment Programme