Various adverse soils, such as peat, acid sulfate, sandy podzolic, and saline soils, are present in the tropical lowlands of southeast Asia. These soil properties vary widely among different soil types. When field crops are cultivated in or introduced into these adverse soils, they will suffer from serious nutritional problems. Nevertheless, some native plants grow well under these adverse soil conditions, and it is important to discern how these plants manage to develop mechanisms for adaptation or tolerance.