[Scpg] Chemical nitrogen vs nitrogen fixing plants

[Fitzsimmons, Mark A PWR]

Thanks Dan for the more detailed report on nitrogen fixing. You answered
my questions about specificity of n-fixing symbiotes, confirming what I
suspected and wrote about possibly needing to inoculate soil with the
proper organisms from naturally occurring know nitrogen fixers. I am
still left wondering: 

are the nitrogen fixing symbiotes that associate with many common
legumes so prevalent that they are probably already in my garden soil,
or should I try to find cultures in nature somewhere, and where would I
find associates for things like peas? I have natural clover but find
peas don't do well in my garden. I always assumed it's because it's too
hot here in so. CA and plant them mostly as winter crops, but now not so
sure. 

When I plant lupines or ceanothus, I will surely find some in the local
mountains and dig up a handful of soil by the roots to inoculate my
plants. 



I am curious to know why Paul and Patrick a couple days ago said K and P
are more challenging. 
Can you illuminate what your concerns are regarding these elements?

Mark