You can turn it off by entering about:config in the URL bar and switching browser.newtabpage.activity-stream.improvesearch.handoffToAwesomebar to false.

WARNING: Changing preferences through this interface not officially supported Hidden settings edited using the about:config tool are explicitly not supported, which means that Mozilla makes no guarantees they will be supported in the future, or that Mozilla will fix them if they break. Mozilla does not test these preferences, and will not in the future. That includes security and performance testing which these preferences may affect.

[Warning added by moderator.]

OMG... THANKS!!! In your photo you look more "woodsy" than "techy" but you for sure solved my problem, which took me 2 days to not accomplish on my own! Thank you VERY MUCH! I cannot tell you how many times, based on directions in other posts, I went to "about:config" changed a setting to "false" and I still could not use my GOOGLE Search Bar, so I was skeptical, but your solution worked! I have used, built and installed OS's on computers since the late 1980s and one tends to get comfortable using "things" in specific ways. I can adapt but sometimes I don't really want to! Haha! I still use "Windows 7 Ultimate" and prefer it! Since the first time I got online, I have always searched from the "search bar" in the center of the screen, so when it started defaulting to the URL Bar I was PO'd, as every letter I input created more "babel/suggestions and unwanted websites" in the URL Bar. I created a temporary work around but was still disappointed with the new clunky nature of even a basic GOOGLE search! Your solution fixed my problem, first try and I'm back to wasting time at my computer again... thanks!!! Sincerely! YES, I'm screaming! THANKS!!! OMG, that was ridiculous!