by Did67 » 09/06/19, 09:00
Attention, no misinterpretation: I am not saying that "sandbox gardening" does not work !!! Since I'm not saying that conventional farming doesn't work ...
I say it's not a lazy man's vegetable garden! And that it is necessarily more "anthropized" - so we are in the paradigm "it is the man who does!" (which I oppose to the PP paradigm: "man makes do"):
a) impossible to have a "real" soil: the soil is an interface between the mineral (the rock which decomposes), at 95%, and the living (the OM which accumulates), at 5% - orders of greatness; a soil is built, by degradation of the bedrock, under the influence of climatic factors, thanks to the energy pumped by the plants, via a "work" done by living soil organisms; a soil undergoes positive and negative influences, the action of the climate, leaching (which releases sodium for example) ...
b) the "tray" (let us consider wider than a planter) on a roof or a balcony, will undergo stronger influences from the climate: the walls heat up in summer, freeze in winter, etc ...
c) we will work with culture media; even if we "cut up" as Christophe suggests, a slice of soil (which is never the case in Paris - remember the question I had 25 seconds to answer!), it will be " disconnected "and" artificialized; the mycorrhizae will not seek minerals at a depth of 2 m, where the soil is still wet and cool in summer; the system will not be "leached" each winter; it will not benefit from the elements released by soil minerals ...
d) there will be no surrounding ecosystem: meadows with ground beetles, hedgehogs, foraging en masse on the flowers of the neighboring meadow ... Suddenly, on the one hand, in the relatively "sterile" environment of the city, we will escape a lot of parasitism (yes, it's not just negative!), but we will not maintain biodiversity, we will not have the auxiliaries (at least in the same proportion (a few ladybugs or hoverflies can settle on a terrace and a balcony - we have many bees in the cities!)
In short, I am not saying that it does not work (at the cost of ignoring the durability of the growing media, fertilizers, irrigation, ...) ... I am not saying that the growing medium culture is not alive (of course there are mass microorganisms even in a flowerpot). I say that it is not a PP with what I set myself as criteria: to produce in abundance more than organic vegetables without pesticides, without fertilizers, often without watering - and of course in my vegetable garden I do not mention it: without artificial lighting (more than 70% nuclear).
To see recently in the newspaper of France2 is "report" on young people who develop kits, with pastilles: the pastille to cultivate a salad is worth twice the price of a salad in store! That sums up the "pros" well. I summed up the "against" ...
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