Sunday, 4 October 2009

Mining for Minerals

The ever excellent BBC Radio Four runs a series called Costing the Earth. This weeks episode looked at mineral deficiency in plant based food (follow the link above to listen to the program again):
  • "Over the past 70 years the levels of crucial minerals in our basic foods have declined significantly. This is bad news for consumers in the west, but potentially deadly news for those in the developing world who cannot afford a perfectly balanced diet.
    Alice Roberts sets out to uncover the culprit and find a solution. Do we need to shorten our food chains, de-intensify our agriculture, or simply turn to the varieties of fruit and veg enjoyed by our grandparents?

    In Perthshire, Moira and Cameron Thomson spread their own mixture of compost and rock dust onto their poor Highland soils. They are convinced that the rock dust is replacing the lost minerals from the soil, resulting in enormous and very tasty broccoli, parsnips and carrots.

    Meanwhile at the University of Nottingham, Dr Martin Broadley uses a combination of mathematics and applied biology to find a way to breed crop roots that extract more of the minerals that are available in the soil.

    From the Cotswold kitchen of food writer Diane Purkiss to the world's largest potting shed at the National Soil Archive in Aberdeen, Alice compares and contrasts the diet, soils and plants of the 1930s and the present day in her search for the world's lost minerals."
Of note is talk of adding rock dust to vegetable patches by Cameron and Moira Thompson (about whom you can read more here). The Thompson's have managed to grow exceptional vegetables from meagre soils using this technique.

Their inspiration comes from a book published in 1982 called, rather dramatically, 'The Survival of Civilisation' by Jon Hamaker and Don Weaver. In this book the authors suggests that glaciers ensured our soils were mineral dense, but intensive agriculture has depleted these minerals. And in the absence of any glaciers in the near future happening along to revitalise the soil, we should do the glacier's job for it! You can download the book for free here.

My composting skills are becoming most excellent (we have lots of dark, rich looking and fresh smelling compost in our bin), and this, perhaps along with a little rock dust, might be just what is required to make Captain Kid and Flash's vegetable patch move up gear next summer! We are currently enjoying a feast of homegrown raspberries, but are hoping to branch out (bad pun intended), in to other berries.

4 comments:

Methuselah said...

This is really interesting - where did they get the rock dust? I don't recall ever seeing such a thing on sale...

Asclepius said...

I don't know where the initial rock dust came from, but there is quite widespread market based upon it now (eg. http://www.fertilizeronline.com/rockdust.php)

I like the tie in of rock dust/vegetable gardening, the actions of ancient glacial processes. It is one of those ideas that really underlines how interwoven nature actually is!

Kat Eden said...

Fascinating ... do you know if certified organic farmers are known to use rock dust to improve soil quality? I'd be interested to know the difference in outcomes between plants grown purely in a soil/compost mix as compared with purely soil/rock dust or all three.

Mineral content is definitely a huge concern (one of many!) when it comes to the quality of our food supply. I always encourage people to add certified organic sea salt or Himalayan salt to their food and water, as it's an excellent way of introducing over 80 important minerals back into the body.

Asclepius said...

Hi Kat - all I know about rock dust is what I have gleaned from that radio program!

The results experienced by Moira and Cameron Thomson are pretty thought provoking in terms of productivity and quality.