NUTRITIONAL CHARACTERISTICS OF SAGE PALM AND OIL PALM IN TROPICAL PEAT SOIL

To make clear the nutritional characteristics of sago palm (Metroxylon sagu Rottb.) and oil palm (Elaeis guineensin Jacq.) grown in tropical peat soil, minerals concentration, organic compounds concentration, a nd photosynthetic rate were estimated, and the obtained results were a s follows. Since, the nitrogen (N), phosphorus (P), calcium (Ca), magn esium (Mg), and sodium (Na) concentration in mature leaves and trunk w ere higher in the oil palm than in the sage palm, but potassium (K) co ncentration was higher in the sage palm than in the oil palm, the mine rals (especially N, P, Ca, and Mg) requirement for the oil palm were h igher than in the sage palm. This indicates that the sage palm will ad apt better than the oil palm to soils with poor nutrients. The mangane se (Mn) and zinc (Zn) concentration in leaves of the sage palm and Ca and aluminum (Al) concentration in leaves of the oil palm increased wi th the increase of aging, indicating that those elements are eliminate d fi om plants through leaf senescence. Tn the sage palm, the N and P distribution ratio to leaves remained almost constant during growth, i ndicating that N and P were predominantly distributed to leaves for ma intaining leaf function. The photosynthetic rate [mu mole carbon dioxi de (CO2) m(-2) LA sec(-1)] at light saturation was lower in the sage p alm (5.8) and oil palm (10.0) than in wheat(25.4). As leaf longevity o f sage and oil palms was longer (about 12 times) than that of wheat (T riticum aevstium L.), and the minerals concentration and photosyntheti c rate remained constant for a long duration of growth, the cumulative carbon (C) accumulation per unit dry weight (photosynthetic rate x le af longevity) in the individual leaf is assumed to be equal or greater than that of wheat. The photosynthetic ability of sago and oil palms leaves is very important for understanding why sage and oil palms have high productivity in spite of a low nutrient environment.