Angraini, Ria WindaHanifah, T. AbuAnita, Sofia2017-01-062017-01-062017-01-06http://repository.unri.ac.id/xmlui/handle/123456789/8851Based on survey result, oil palm plantations in the area Pakning Asal Bengkalis regency in the last 5 years (2010 - 2015) were burned by different frequency. There were soil that were never burned and once burned. The purpose of this research were to determined the effect of fire with different frequency at the total content of Fe, Al, Mo and C/N. The total content of aluminium and molybdenum were determined by using Atomic Absorption Spectrophotometer. Iron and carbon total were determined using UV-Vis Spectrophotometer. Total of nitrogen was analyzed using Kjeldahl method. The result showed that the total of Fe, Al, Mo increased at the once burned soil and C/N ratio increased at once burned soil . The total content of Fe, Al, Mo at the once burned soil were 69.20 mg/Kg; 33.83 mg/Kg; 2.16 mg/Kg and the value of C/N ratio increased from 16.51 to 20.59.otherdifferent frequency of firesKjeldahl methodAtomic Absorption SpectrophotometerUV-Vis Spectrophotometerstudent Paper Post Degree