Hi there, I once used clear plastic to solarize a garden. It had been left alone for years. It was filled with bermuda grass. I knew I could add enough compost to enliven the soil again. So I went for it.
If you choose to solarize, it will kill everything. The good and bad.Use a thick clear plastic, make sure the edges of the plastic is secured. I dug a trench around the garden and used that soil on top of plastic. I also watered the grass before solarizing.
In conclusion it was a lot of work. It did kill a lot of the grass, but the grass will always be there, in smaller and smaller clumps.
Interesting topic. Many of the modern market gardeners who have a media presence these days are using silage tarps to prepare their fields and between crops. The warmth causes weed seeds to germinate, then the lack of light kills them. Seemingly a good option if you want to avoid tillage in a production farming scenario.
It would be great to see a study on a tarped area vs a control, with microscopy to show the soil organisms before, during and after tarping. It would be nice to see how long it takes for the fungi and bacteria to rebound.
I have heard several interviews with Bryan O'Hara, who farms in the NE US (I can't remember which state exactly, I want to say New Hampshire). He uses very short applications of clear plastic to solarize beds between crops, and also to kill cover crops. I believe something like 24 hours or so in the summer. He has done temperature tests and found that the very high temperature is limited to a shallow layer on top of the soil, and the soil below an inch or two doesn't increase much in temperature. Does it stand to reason that the soil microbes would simply move down, and then back up again once the cover is removed?
I'm not sure. I have used tarping in one area to smother bindweed, and planted squash through holes in the tarp. I got the idea from Charles Dowding, who suggested that in some way squash is alleopathic to bindweed. I used free lumber tarps that I can get locally from the hardware store. (Otherwise the tarps go straight to the landfill) Under the tarp the worms certainly had a heyday, however I am concerned about creating habitat for rodents as well.
I use landscape fabric on my beds, which is woven so allows water and air to pass through and therefore I believe isn't so harsh on the microorganisms.
Wherever possible I cut any vegetative grown and lay hay or cut grass on the soil before putting the fabric down which generally at least starts to rot away at the soil surface by the time I lift the fabric up again for planting.
Clear plastic doesn't work where I am we don't get enough strength in the sun to kill anything, but black certainly does. and as far as I can see it doesn't kill any bugs under it. Under my black plastic I have thousands of worms, slugs, snails small waspnests frogs toads.. and VOLES and therefore cats chew holes in the plastic to get to them, sigh. I have left plastic down for 2 years at a time and everything seems to love it under there. Obviously I cannot see the bacteria but if there is enough air for worms I would think there will be enough air for them. (these are large sheets of plastic 110ft long by 33 ft wide)
Sena Kassim wrote:Hey Skandi, I wonder if cardboard/sheet mulching would kill those pesky weeds, all the while nourishing the soil.
Some places around here have a lot of voles. Each summer our cats put on a lot of weight. Some places are so soft to walk, because of all the vole tunnels.
Cardboard seems to work on everything I have except horsetail and creeping thistle (canada thistle?) those just come straight through. I only use it in the pollytunnels though as where on earth do you get a half acre of cardboard and enough things to hold it all down (it's very windy here) I lost about half my parsnips this year to voles and a significant amount of potatoes and carrots, the cat loves them as do all the raptors we have. We even have house martens (in the house!) but they don't seem to make much of a dent, I guess they probably do it would be worse without I am sure.