Allotments 4 All

I feel I should understand something of the chemistry of the soil and how it relates to healthy plants, particularly regarding the various nutrients and how deficiencies are identified and corrected, by natural means.

Can anyone put me onto any suitable sites, or even books, that will cover the essentials in a digestible form?

hi
you can have a look here. 
http://www.rhs.org.uk/advice/profiles0705/nutrient_deficiencies.asp

any more detailed info, just google i suppose.

Some sites I have used:
How the plant takes up nutrients:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/X/Xylem.html
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/Roots.html
What the nutrients are and more about the forms in which they exist:
http://nutrients.ifas.ufl.edu/nutrient%20pages/Overview2.htm

Thank you for those links, I can now pretend to be more educated !