Nitrogen Uptake by Sago Palm (Metroxylon sagu Rottb.) in Leyte of the Philippines

Abstract

 Nitrogen uptake by sago palm with the application of nitrogen fertilizer (urea) with ¹⁵N-labeled ammonium sulfate was studied in Leyte of the Philippines to estimate the effect of nitrogen fertilizers on sago palm growth in the early to middle stages. The first application of nitrogen fertilizers for determining sampling portions of leaflets was carried out at the early growth stage of sago in July of 2005, and the second nitrogen application trial for determining nitrogen uptake was done in the middle growth stage in July of 2007, after combining two 4 m x 2 m plots into one 4 m x 4 m plot. Since the nitrogen contents in the upper, middle, and basal positions of leaflets were different from the sampling in February of 2006, the middle leaflet of the third sago leaf was used for analysis. As the sago palm’s fertilizer use efficiency in the middle stage ranged from 10 to 20%, the use of nitrogen fertilizer for sago production should be limited.