I have been thinking of using dirt or sand as a broadhead target. Any ideas, plans, or comments on whether this should work? I was thinking of making a three sided frame out of landscape timbers and then filling the center with sifted dirt or sand and then just using a whiffle ball, etc. for a target to sit on the dirt. will this work?
This idea came to me after i had to throw my 10 year old block target away.

FWIW, I used a sawdust pile that worked out quite well. I would think sand would be pretty rough on arrow finishes and broadheads. Clean dirt might be better unless it rained. The whiffle ball worked pretty well except on the rare occasion that I actually managed to hit it the arrows could be hard to pull. I ended up using wadded up paper balls of various sizes.

Bob

Sand pile is an excellent target butt for broadheads, except in Colorado where it freezes for much of the year.  Wet your sand down and it'll stack quite nicely.  One of the best target stops I can think of when it's not frozen.

A big ball of synthetic modeling clay works great too, especially in the removable vitals zone of 3-d targets.

Make certain you sift the sand or buy it that way.  A moderate sized stone in the sand or dirt can ruin a broadhead.  Otherwise.. it works great.
ChuckC

sand is good might wont to look at your cat population, you may find a suprise while retriving your arrows  

Anybody else use sawdust?  What did you put it in?  I have access to lots of saw dust...

Sand makes a great back stop/target butt. Like you thought, a three sided "box" will keep it from spreading so the sand stands a little higher and stays that way.

It really isn't all that hard on arrow shafts, but it will scour the paint off a broadhead in short order.
I really love conditioning my broadheads in the sand pit... gets rid of any noise producing burrs and rounds the tips nice and even.

Except for judo's when stumpin, I never practice with anything but broadheads and that helps with confidence when shooting at game.

And bloodyarrow is right!!! Every cat in the neighborhood will find your sand pile... a small rake kept handy will fix that problem.

I get a tube of Walmart's cheapest tennis balls for targets on the pile. Easy to focus on, arrow removal isn't all that tough.
 

Note the kernels of corn on the sand pile... starlings love corn.  

I shoot broadheads into sand when it is not frozen.  I ussually shoot at white bottle caps, they are a cheap,small target.  The only problem I have is that I get full penetration into the dune sand and have to dig my arrows out.  I will probobly try mixing in some clay to see if that tightens things up. The sand will wear the finish off arrows, but it takes several years of constant shooting.  Ussually I loose or damage arrows quicker than the finish starts to look bad so its not a real big issue.

Before 3-D targets became the rage, most archery clubs around here offered broadhead tournaments using cardboard silhouette targets hung from wires a few feet in front of sand bunkers.  The arrow passes through the cardboard, the hole it leaves behind telling the shooter where he hit (and his score).  Then, the hole is taped with masking tape from the back side of the target.  

Pretty easy to string a couple of wires from posts on either side of your sand bunker and to construct your own cardboard silhouettes.  And for practice, there's no need to tape the holes, but taping does extend the life of the target.  Cardboard does increase feather wear, but they  last a long time before the shafts need to be refletched. Have fun.