Tie the pound to the UK wheat yield!

I tried to post the following comment to the William Rees-Mogg column in this morning's the Times, linked here but repeat it below as it has not appeared: I date the start of these present problems back to 1971 and Nixon freeing the dollar from gold. Since that time currencies have merely moved against one another in a macabre manner apparently directed by government whim and market greed. No investor has anywhere realistic or reliable to currently protect this meaninless worth except in gold or commodities, the value of the latter being themselves doubtful due to the approaching macroeconomic slump. A Central Bank that now tied its currency to something tangible and of constant worth would attract sufficient sound investors to better weather the hurricane. Given that wheat has been the staple of the West I suggest the BoE consider fixing the pound to the value of the annual wheat yield in an acre of land in the Vale of Evesham.