Is earth an inertial frame of reference? If not why?

Earth is non Inertial Frame.

It has acceleration.Hence it is accelerated with’g’.so, it is non inertial frame.

but the value is very less in comparision ang hence can be neglected.

So, we can assume it as Inertial Frame.And Can apply Laws Of motion.

 

@ rajesh 
a non inertial frame is that which is on rest or is moving with constant velocity and no acceleration . though earth has an acceleration , but that acceleration is very very less and is almost negligible . 
so, earth is considered as an inertial frame of reference . 
BUT ITS BY CONVENTION ONLY .. 
HOPE IT CLEARS YOUR DOUBT ..