Money is swirling down the drain, right under your nose.
1.) You're going to lose a lot of money by not covering your silage at all. You'll spend less money on labor and materials than you will on silage loss.
2.) Covering your silage, but it is packed very poorly. A steeper pile has a higher risk of rips and holes, poor tire placement, and more areas for oxygen to creep into the silage.
3.) Covering your silage, but not well. The goal of silage plastic is to block out the oxygen. If you put plastic and tires on your pile only for it to bubble up and blow away, then you might as well not have covered it.
--> Maintain a 3-4 foot(minimum) of overlap on your plastic seams.
--> Keep the uphill seam on top of the downhill seam to prevent water seepage.
--> Prevent wind getting under the seam by putting the dominant wind side on top.
--> Put heavier coverage of tires(bales, sandbags, etc) on your seam to create a better seal and keep seams from blowing up.