Healthy soil and sustainable growing

[Harvey Ussery <harvey@themodernhomestead.us>]

Unless I missed it in the thread, I don't think anyone has mentioned 
very deep rooted fertility plants (dynamic accumulators) in the 
equation. Certain plants with extremely deep roots "mine" the deep 
subsoil of minerals not available in the top layers of the soil profile. 
When they die or shed their leaves on going dormant, the minerals become 
available to more shallow rooted crops. Of course, they can be cut and 
applied elsewhere as mulches or to make compost.

Examples are alfalfa (which has been found to grow roots as much as 23 
ft deep) and comfrey (roots 8 to 10 feet)--there are many others.

I read the observation somewhere that in a typical soil profile there is 
enough mineral fertility in the depths to support agricultural 
production for 100,000 years. A fanciful claim, perhaps, but it 
illustrates the value of certain useful plants that can serve as "pumps" 
of deep subsoil mineral fertility.

~Harvey

--
Harvey in northern Va
www.themodernhomestead.us

My book, THE MODERN HOMESTEAD POULTRY FLOCK, will be published next year by 
Chelsea Green Publishing.