Plastic can stop the air and moisture exchange a good healthy soil needs to stay good and healthy. Most everyone I know that did once use plastic as mulch regretted ever doing that.

I live in snow country with drought. Use newspaper and cardboard layers. They will do well for what you want to do.

I don't know where I would obtain that much of either cardboard or newspaper. Cardboard will be easier to find for me.

Sounds like I'd be better of just leaving it uncovered and irrigating occasionly over the next few weeks than covering with plastic untill we get some wet weather?

It's just that this course soil drys out so fast.

Kimmsr: I read this and it made me think the plastic mulch would be ok, especially for temporary.

http://en.wikipedia.org/wiki/Plastic_mulch

Aside from the disadvantages noted above, plastics are made from non renewable resources, can be expensive, and when taken up pose an environmental hazard with disposal.
Recyclables, such as newspaper and cardboard, will do the same thing as plastic (except maybe raise soil temps) and add organic matter to the soil, something plastic will not do.

I have no reason to dissagree with those downsides of plastic.

I live in the sticks on acerage, a homestead, so to speak, and collect stuff. I always have lots of it around from various projects, keep it well after most would, ragged and torn.

I think I'll put some down, just untill the wet comes. Water the soil first. At the least, what with the weather cooling so much now, it will keep the soil warmer, and keep the moisture in. Irrigating bare dirt runs my electric bill up, so it will help in that regard too.

Wondering where on this glorious planet you are located?

If warmth is important, clear plastic will do the job better. Even better, it will encourage annual weed seeds (if there are any) to germinate, and they will die when winter arrives.

I use black plastic every year. End of season I till, water well, then cover the whole area in black securing the edges by burying it.
I leave it on until spring, then remove and sow directly, with no further disturbance.
This effectively prevents compaction due to snow load, kills off all weed seed at the surface and warms the soil in the spring, has no detrimental effects on soil bacteria.
I swear by it and encourage anyone to give it a try, works for me.

I agree with Beeman.

Also, if you have a horse manure supply, you probably have a store that sells feed. If you can get feed, then you can raise rabbits. If rabbits are an acceptable choice for you, they will make mountains of absolutely wonderful manure that can be added fresh or pre-composted in a large worm bin. The rabbits themselves taste good and if you have a dog, the fat and non-digestive-tract organs are a welcome treat. The mountain of manure they give you does come at a cost, however, and I estimate each rabbit will eat up to 3 50lb sacks of feed per year. Ironically, I have read recommendations to use rabbit food directly as fertilizer, though that seems a bit expensive.

If your USDA Cold Heartiness Zone is between 3 and 9, you should be able to grow a plant called Comfrey. It's well known, has many gardening uses, grows like wildfire, and rabbits love it.

I mostly feed my rabbits commercial pellets, but feeding some Comfrey helps keep the feed bill down in the summer. You normally can't burn it with raw manure, even chicken, and it just keeps making big, mineral rich leaves for your garden and livestock. I personally wouldn't make the stinky, anaerobic teas with it or till the green leaves or roots into the garden though. This plant is a survivor, and it should be grown in a dedicated patch that will only have Comfrey forever. If you give it a little (or a lot) of nitrogen, it will dig down and get whatever else it needs on its own, supposedly. I've found that it does do better with some moisture (even just that retained from mulching), and at least a couple hours of direct sunlight.