Biophysical properties of various ages oil palm plantation in Ultisols of Bengkulu

Abstract

Abstract Oil palm plantation (OPP) expands to soil with less suitable including Ultisol. The purposes of this study were (1) to compare some selected soil properties among various OPP ages and (2) to determine the correlation among the selected soil properties. A Completely Randomized Block Design with single factor treatments of oil palm age consisting of 2-yr, 3 -yr, 4-yr, 8-yr, and 32-yr of OPP, and all treatments was repeated three times. Blocking was based on the OPP floor positions: circle weeding (CW), frond stack (FS), and between palm (BP). All data were statistically analyzed using ANOVA with 5% a, and DMRT at 5 % a was used to compare treatments. The result showed that using Ultisol in OPP with good management especially keeping or improving soil organic C through maintaining understory vegetation, may reach soil sustainability. Increasing oil palm ages followed by increasing organic C, water holding capacity (WHC), and decreasing bulk density (BD). The highest oil palm root density (OPRD), oil palm dray root density (OPDRD), and CO2 emissions were found at the 8-yr OPP, while the highest value of understory vegetation biomass weight (UVBMW) and understory vegetation biomass dray weight (UVBMDW) were reached at 4-yr OPP. Organic C was weakly correlated with actual soil moisture (ASM) (r=0,485) and aggregate stability (AS) (r=0,465)