-As well, what can I use enrich
>the soil without artificial fertilizer (hmmm... i'm afraid
>of that one ;)


Have ou been in a natural ecosystem , the soil there fertilise itself . Left
alone the soil naturally build up and become richer and richer capable of
sustaining huge trees.
Tilling the soil and reducing biodiversity interfere in that process
rendering necessary an outside input to maintain the fertility.
The outside input will necessarelly  be out of balance with what the soil
need ( especially so if refined or synthetic)
a compost heap try to resolve the problem by recycling the plants back to
the land .2 problems 1 the rotting under heat don't  occur in nature 2 it is
lot of work to handle .
by encouraging biodiversity of species in a garden bed and recycling waste
by composting on the surface (  layer of mulch ) you enhance rhe micro
ecosystem of the first cm of topsoil
one important things by cutting back weeds and using them as mulch around
your vegetables you create a dying back of their roots system that will
leave room for air and water and nutrients  to circulate. ( the soil get
naturally tilled).
jean-claude