Healthy soil and sustainable growing

[Harvey Ussery <harvey@themodernhomestead.us>]

On 09/30/2010 07:13 AM, paul@oneseedling.com wrote:
> Once nutrients leave the farm they must be replaced from other 
> sources. ~paul@oneseedling

As has said been earlier in the thread, by no means entirely true. Three 
sources of *renewable* nutrients on-site come to mind:
* Deeply rooted crops (alfalfa, comfrey, others) that "mine" mineral 
fertility from the depths far below the reach of more shallow rooted crops.
** Legumes set nitrogen, a major nutrient need, in the soil without 
purchased inputs from elsewhere.
*** And most important of all, sunlight is constantly being added to the 
equation. While sunlight doesn't create mineral content that's not there 
(other than N), the more stuff it's helping to grow on the site, the 
more fertile it's going to become overall.

And we shouldn't think of fertility as solely chemical "nutrients" you 
can test for in a lab. Fertility is also about how "alive" the soil is. 
So incorporating livestock on most sites should bring a net gain in 
fertility--their manure over time boosts soil microbial populations, 
boosting fertility above and beyond the lab-analysis level of chemicals.

Finally, whether or not some minerals are *available* has a lot to do 
with the soil food web community. Boost those guys and there is more 
*usable* mineral content even if we haven't shipped in amendments from 
elsewhere.

~Harvey

--
Harvey in northern Va
www.themodernhomestead.us

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