SIFAT KIMIA ABU VULKANIS GUNUNG SINABUNG SEBAGAI SUMBER HARA TANAH DAN ANALISIS SPASIAL DARI SEBARAN MATERIAL HASIL ERUPSI TAHUN 2019

Abstract

[SPATIAL ANALYSIS OF MATERIAL DISTRIBUTION AND CHEMICAL PROPERTIES OF VOLCANIC ASH FROM THE ERUPTION OF MT. SINABUNG IN 2019]. Mount Sinabung, located in Karo Regency, North Sumatra, first erupted in August 2010 and continued from 2013 to 2022. As one of the parent materials for fertile soil, volcanic ash reserves large amount of nutrients. The research was aimed to determine the chemical characteristics of volcanic ash and to map the distribution of volcanic ash from Mt. Sinabung eruption material in 2019. This study examines 22 samples of the of volcanic ash collected based on a terrestrial survey with the grid method. The results showed that volcanic ash within a radius of 3-5 km from the center of the eruption (total area 1,402.83 ha) have a pH-H2O ranged from 5.30 to 6.27 (acid to slightly acid), Mg > Na > Ca > K, in order of base cations, with moderate to very high criteria, available P ranged from 35 – 165.96 mg/kg (very high), and CEC ranged from 12.92 – 21.78 cmol/kg considered low to moderate. Therefore, the volcanic ash deposits can provide a significant quantity of nutrients for future soil fertility in agricultural areas affected by eruptions.