Sugar

We have a septic tank and this is our Sugar standing on top of the drain field which we can't seem to get anything to grow on except a few sparse weeds.  We also can't figure out what's on there that she just has to pick at.  The hubby is thinking about fencing it off to keep her away from it.  She has 3 acres of fresh grass to  eat off of.  It may be the grit of the sand she picks at.