抄録
Among various agro-ecological units in the Mekong Delta of Vietnam, the Broad Depression and the Plain of Reeds had long remained unused for agricultural purposes due to adverse environmental conditions such as deep flooding, poor soil-nutrition and potential acid sulfate soil. Despite these conditions, rice cultivation expanded to a great extent in both areas after the end of the Vietnam War.
Under the new postwar socialist regime in the South, the government promoted the exploitation of these areas. Excavation of canals and construction of canal networks provided migrants with a place for settlement and the fresh water from the Mekong River enabled them to reduce the potential acidity by washing away the active acid emerging after land reclamation. As this process proceeded, spontaneous pioneer farmers rushed to these areas to reclaim rice fields prior to the implementation of the government's socialist land reform program. As a result, the former grass-and-forest wetlands have been almost completely converted into rice fields.
Since the end of 1980s, however, a debate has arisen about wetland conservation. This coincided with the “privatization” of the agricultural production system, the introduction of “doi moi, ” new economic policy in Vietnam, and the partial success of rice growing in these areas. The government has enclosed wide areas as natural reserves where Melaleuca, an original species of vegetation, and secondarily emerged aquaflora are preserved. On the other hand, under the pressure of rapid population growth, both the pioneer settlers and new migrants still seek to extend and intensify rice cultivation in these areas.
