The role of Sub-bituminous coal powder with Sodium Hydroxide (NaOH) to improve chemical properties of Ultisols

Abstract

This research was conducted in soil chemical laboratory, Faculty of Agriculture, Andalas University, Indonesia from December 2016 until May 2017. The purpose of this research is to determine the level of activeness of powder of Sub-bituminous coal with Sodium Hydroxide (NaOH) and to determine the appropriate dosage of the mixture in improving the chemical properties of Ultisols. This research was conducted in 2 stages: first stage study with 10 treatments (1% to 10% (w/w) NaOH) and the second stage study on soil using 15 treatment combinations (3 doses of powder Sub-bituminous coal with 5 doses of NaOH). The results of the first stage of research are the addition of NaOH in Sub-bituminous could increase the activity of powder Sub-bituminous coal with parameters of pH, CEC, and increases the number of O-H, C=O, and CH3 groups. The results of stage II study is the provision of a mixture of 20 ton.ha-1 of Sub-bituminous coal powder and 10% of NaOH were able to increases the pH of H2O, CEC, organic-C, Available-P, and Total-N Ultisol each of 1.49 units, 28.08 me.100g-1, 1.63 % C, 2.37 ppm P, 0.06% N, and decreases Al-exch Ultisol by 1.17 me.100g-1 and, SAR Ultisol by 0.03, and ESP Ultisols by 0.82 % compared to natural soil.