Vetiver in a permaculture environment

I first met permaculture in 1990 in Australia; since then I often spoke about it, but never here nor in my vetiver activity context: today I would like to speak out about the contribution that vetiver can give to a type of agriculture as beautiful as the one imagined by Bill Mollison.

Permaculture needs huge quantities of mulch that often is contaminated with undesired seeds, somethimes we'll have to consider the use of sprays.
This mulch (often hay) is needed to cover the ground and protect it from the elements, and favour the developement of life underneath it.
given the durability of hay and its cost to buy or produce, havig to replace it becomes a bit of hassle that can easily be avoided.

The designs used in permaculture, often use vegetative hedges to promote the growth of precious crops: "suntraps" circular sections of windbreak open towards the sun are planted in order to maximize the available heat in the winter period. To apply vetiver hedgerows to this purpouse will generate free mulch (or energy) when the precious cultures do not need protection like the summer periods.

As known, vetiver mulch has an exceptional durability and resistance to rotting so to be often used for thatching. This can generate good savings of time, money, effort and fossil fuels for the permaculturist.

Still needs to be assessed if it is preferable to keep vetiver mulch as it is, or if a fine chopping is better.

Any contribution is wellcome.