Most of it is a load of unscientific bull!!

Negative ions are exceedingly mobile and the Earth's surface has a negative charge; therefore, negative ions are repelled from the Earth. This repulsion creates a normal ratio of positive to negative ions in the range of twelve to ten.
Negative ions are not repelled by the Earth, as the atmosphere holds just as many positive ions, and so they balance each other out, otherwise out atmosphere would have been stripped away billions of years ago.

Also the ground releases electrons constanly which suck up ions and try to reduce the -/+ count to zero, so that helps keep the balance as well. Weather also produces these cleaning electrons, and these are returned back to the ground via lightining., which the Earth has thousands of strikes a day.