<資料 ・ 研究ノート>東南アジア低湿地の土地利用

Abstract

This is a review paper on the present use and the future potential of swamp land in insular Southeast Asia. Though most swamp areas have been unutillzed or underutilized, they have some uses, traditional as well as recent. These include the starch extraction from sago palm in Irian Jaya and other islands, the pineapple cultivation on peats in Peninsular Malaysia, and the rice cultivation by tidal irrigation in Sumatra and Kalimantan. In this paper, the land conditions, technology employed, the economy of production, the population involved and their social background, and the limitations and potentials of future development of these uses are first described and discussed. Next, various experimental works on peat soil are reviewed, which include studies of both annual and perennial crops. Based on these, several perspective views are presented. They are as follows : (a) the equatorial swamp is so unique an ecosystem that efforts should be directed to devising similarly unique farming systems adapted to it rather than to bringing in systems evolved elsewhere by drastically modifying the land conditions; (b) the deep peat swamps, of which the underlying mineral layer is so low that gravity drainage would eventually become impossible due to subsidence, should be left untouched given the present state of the art; (c) lowland rice could be planted in some parts, but production of surplus rice in any significant amount seems unlikely due to the inherently low labor, if not land, productivity of swampy areas; and (d) the low productivity per unit area of swamp land would not itself deter its use, and, therefore, such farming systems that might be low in terms of land productivity but high in terms of labor productivity should be sought.