<strong>Paper Title</strong><br>
Activation of Sub-Bituminous with Urea and Dolomite to Improve Nutrient Content of Ultisols and the Growth of Oil Palm Seedlings<br>
<br>

<strong>Abstract</strong><br>
This study was aimed to examine the effect of interaction between sub-bituminous powder and activator to
improve chemical properties of Ultisols and the growth of oil palm (Elaeis guineensis jacq) seedling. This research was done
in the Laboratory of Soil Chemistry and Experimental Garden of Agricultural Faculty of Andalas University from December
2016 until June 2017. This study applied Completely Randomized Design (CRD) with 3x3 Factorial and 3 replications. The
first factor (activator) included (A0) without activator, (A1) 10% urea, and (A2) 10% dolomite. The second factor (dose of
sub-bituminous powder) consisted of (B1) 10 ton/ha, (B2) 20 ton/ha and (B3)30 ton/ha. Result of this study showed that: (1)
Sub-bituminous powder added was found to interact with activator in increasing total-N of soil and plant height, in which the
highest total-N and plant height was produced by the dose of sub-bituminous powder of 30 ton.ha-1 with urea as activator;
(2) The addition of sub-bituminous powder at dose of 30 ton/ha was able to increase pH, organic-C, available-P, CEC of
Ultisolof 0.4 unit; 0.35 %; 2.09; 7.41 me/100g, respectively, compared with the dose of 10 ton/ha; (3) The addition of urea
activator increased pH of 0.09 unit, organic-C of 0.18 %, available-P in Ultisol of 0.92 ppm, and CEC of 2.10 me/100g, as
well as decreased Al-exch of 0.49 me/100g compared without activator.
Keywords - Dolomite, Oil-Palm Seedlings, Sub-Bituminous, Ultisol, Urea,