Abstract
About 20 thousand ha of land are devoted to sago cultivation in Sarawak. Sixty percent of sago palm in Sarawak is grown on peat soils, and 33% is grown on alluvial soils. Copper (Cu) deficiency has been recognized and is thought to cause many severe disorders of plants on tropical peat soils, but it has not appeared in sago palms, so the sago palm is expected to be a potential food and industrial export crop utilizing the marginal land resource of deep peat soil. The abundance and distribution of Cu and zinc (Zn) in tropical peatlands, the relationship between sago palm growth and Cu and Zn content in the sago palm, and the evaluation of sago palm plantation as sustainable land use for tropical peat soil are discussed.
Copper and Zn concentrations distributed in soil and aquatic environments in tropical peatland were low, ranging from nd to 25.1 µg/gCu and from 6.83 µg/L to 32.4 µg/gZn. Despite low Cu and Zn contents in peat soils and water, Cu and Zn deficiency did not appear in sago palm tissue, although Cu content was low in tissue taken from sago palms growing on deep peat soil. The sago palms on deep peat soils grew more slowly than those on shallow peat soils and alluvial soils. The preliminary input and output study of Cu and Zn showed that Zn tended to be lost from tropical peatland under sago palm cultivation. Sago palm cultivation without appropriate planning would not qualify for sustainable land use in tropical peatland.