Re: CULT: Black plastic vs. Clear
Loberg wrote:
>
> >By the way, black plastic will not sterilize soil.
>
> Ok... now I am curious. I've heard that everyone uses Clear, but when
> I think about it, why wouldn't black do some good?
[snip]
> By letting the sun rays through the clear
> plastic... does that do something else? Does it just allow the sun's heat
> to get down further deep in the ground? Otherwise, it would seem that
> black would be hotter than clear...
Think of solarizing your soil in the same way that your car heats up in
the sun. Light enters the soil through the plastic (clear type) and
strikes the soil heating it. The soil in turn oil gives off infrared
radiation (much lower frequency - longer wavelength) sensed by us as
heat. The infrared is reflected back towards the soil by the plastic
(the plastic is not transparent to this frequency radiation). Soil heats
up more etc.
Black plastic is not transparent to light (I know - obvious) but it does
absorb the light and heats up. However, most of that heat is radiated
off to the air above it and not to the soil underneath.
John | "There be dragons here"
| Annotation used by ancient cartographers
| to indicate the edge of the known world.
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