Selection of azotobacter from dry land and its effect onmaize seedling

The productivity of important local food crop maize in dry land of Nusa Tenggara Timur Province, Indonesia was low since it cultivated by using conventional method without appropriate plant nutrition system. A way to enhance maize yield is inoculation of beneficial microbes, Azotobacter. The purpose of this research was to isolate and select Azotobacter to be used as biofertilizer based on N2 fixation, cytokinin as well as exopolysachharide (EPS) production from six indigenous Azotobacter isolates; and their capacity to promote maize seedling growth. The nitrogen fixation capacities of native Azotobacter in N-free media varied from 0.01 to 0.39 µM C2H4/g/h. Cytokinin production of these strain in liquid culture was 0.11 to 40.04 mg/L while EPS content in liquid culture with nitrogen varied from 0.4 to 27.3 g/L. Bioassay on maize seedling performed in nitrogen-free liquid showed that Azotobacter AS4 promote root growth of maize seedlings.