Status of Azotobacter at coffee arabica rhizosphere in Bener Meriah Regency of Aceh Province

Abstract

Coffee is one of the superior export commodity from agricultural sector in Indonesia. Arabica coffee produce especially from Aceh Province especially from Gayo High Land, one of these is from Bener Meriah Regency. One of limiting factor of production of arabica coffee in Bener Meriah Regency is N-total of soil is low. There are soil microorganisms can fixing N atmosphere, one of these is Azotobacter. Azotobacter can found in rhizosphere. This study aims to obtain status Azotobacter on arabica coffee rhizosphere that is the population of Azotobacter at different altitude and screening the capability of Azotobacter to increase N-total of soil. The soil samples used were taken from arabica coffee rhizosphere in Bener Meriah Regency at 800-1600 m MSL. The method used is the descriptive method to analyze the population of Azotobacter at different altitude and screening the capability of Azotobacter to increase N-total of soil. The result obtained that the highest population of Azotobacter was found at 800-1000 m MSL and the population of Azotobacter almost the same at 1000-1200, 1200-1400, and 1400-1600 m MSL. The result also obtained that three isolates of Azotobacter have capability to increace N-total of soil than that of control.