This year I have decided to build a temporary maize clamp in the field have you built one and what is the best way of covering the plastic sheets without using old tyres.

A friend builds his every year with big bales.  Another neighbor didn't use anything, he just piled the silage, packed with duals so he was less tippy.  I saw the results of both, the bales worked well, but so did nothing.  No one I know of covers their pits here, I suppose if you don't want to use tires you could use big stones to hold down the plastic. 

 i dont really know much about building clamps, but from a problem solving point of view, maybe you could use a small heap/ridge of soil/gravel/dirt round the perimeter to hold down the sheet?

We build a maize clamp every year on rented ground. the sides are from bales, then a layer of soil is put around the edge to form a seal. however you have to put tyres down over the main surface, if the wind catches the sheet it would be gone in seconds otherwise, and the maize will spoil if air gets to it aswell.

alternatives to tyres are bales, or rubber mats (rather expensive way of doing it though!)

We have used a bag before and that works well. You just have to have one big thing like a rock or a large tyre to hold it shut when you feed from it.

 Fed Up,

Here after making sure the surface is smooth with no soft holes and the sheet is evenly tensioned we often but "boudins" plastic sausages filled with pea gravel round the edge (& sometimes over the clamp every 4 or 5 m).

Sometimes people cover with a fine mesh first as extra protection for crows/cats etc but costs too much for one year only. My neighbour covers his sheet with sawdust which seems to work well, another variant is sand or soil. 

Heres a photo of a boudin:

And a link to the website where they sell the mesh stuff as well.

Bon Courage.

JC.

We cover our silage and crimped grain with plastic sheeting held down by a layer of dung usually old silage, it works well just have it tipped and ready to put up with the buckrake when the clamp is full. Have covered it like this for years keeps the cover in place and easy to take off.