I'm sorry, this is just too interesting and I must chime in with my 2 cents.
When we look at the determining factors light, water, nutes and air, the only thing that seperates hydro and soil is the actual medium. Having experience growing both I will say that IMHO, the major differences are the growth rates and yeilds. These can both be explained by what the roots have to do get access to water and nutes. In soil the roots have to work harder, thus spending more growth energy below the medium.
I always hear soil growers saying that their buds taste much better then hydro grown buds, but if they are using chemical nutes then they are feeding their plants the same thing as hydro growers do. The problem that hydro growers have sometimes with taste is that they have not properly flushed all of the chemical nutes out of the plant, as hydro grown plants usually have a higher concentration of nutes because it is easier for their roots to absorb the nutes.
Soil grown plants have a harder time absorbing nutes especially at the end of their life cycles because they are probably starting to get root bound if they are not fully root bound already. This makes it much easier to flush and all of the soil grown plants nutrient stores get used more readily.
IMHO, the only way to really improve the taste of well grown soil or hydro cannabis is to use Organic nutes, and remove the hash chemicals.
As for outdoor grows, I believe that growing outdoors is the best way to grow, taking advantage of the sun, natural co2 and other elements. The problem is that those same elements can be your down fall. There has to be some level of environmental control, to grow outdoor plants that will rival finely grown indoor MJ, IMHO.
This year I am setting up what I feel is the best of all worlds. I bought a greenhouse for my backyard, which is very private. I am going to use this greenhouse this year with a soiless mix of coco, vermiculite and perlite. I am going to control the entire environment but still benefit from all of the natural elements. I have bought 300w of solar panels, and made a cheap solar generator to run my fans and blowers and pumps. I will be using all organic nutes from Advanced Nutrients.
So technically I will be growing true organic, HYDROPONIC buds under the great halide in the sky. This should be good.
I used a homemade passive solar greenhouse last year, with soil and got great results, I love greenhouses, even up here in Canada I can start my clones in early april under the sun.
BY the way, I am a Canadian medical user so I do not have to worry about the cops, just robbers, and my yard is very concelled but gets great sun. I am so excited.
:hubba:
