Population of Rhizosphere Bacteria on Several Species of Crops In The Tailings of Ex-Gold Mine

Abstract

Tailings of ex-gold mines leave several environmental damage problems. Environmental damage causes disruption of microorganisms including bacteria. The revegetation of ex-gold mine tailings in Menjalin sub-district, Landak district, West Kalimantan has begun by local communities using agricultural crops. Women as farmers have an important role in the tailing revegetation process using agricultural crops. Therefore, women can help improve the tailings ecosystem as well as the family economy. The objective of the study was to detect the presence and density of bacterial populations in the rhizosphere of the revegetation crops. The research was conducted by survey method. Soil samples were taken compositely from the rhizosphere of four species of agricultural crops cultivated in tailings, i.e: Capsicum frutescens L., Solanum melongena, Ipomoea batatas L., and Manihot utilissima. The results showed that soil bacteria found growing well in the rhizospheres of four species crops. Two genera of bacteria were found in the tailing rhizosphere of ex-gold mine in Menjalin sub-district, namely Azotobacter and Pseudomonas. The bacterial population density in the rhizosphere of M. utilissima was significantly the highest. Meanwhile, the bacterial population density in the rhizosphere of C. frutescens, I. batatas, and S. melongena did not differ in the medium category. Further investigation found that the bacterial population in the rhizosphere of M. utilissima was 126.8 – 217 times denser than the other three crop species.