The book seems so clear, but when I compare my soil test to the expected targets, I'm completely bewildered. My county offers 5 free soil tests, so I did that instead of Logan. It's limited to the major elements, but at least I can try to get that right. Here's the source of my confusion:
My TCEC is 16.7
My pH is 6.1
My OM is 24.4 (I
know!)
First confusing thing: Using the N calculations, I have too much N. And no wonder. But the lab says my nitrogen levels are very low (maybe tied up by imbalance?). I'm not sure how to deal with that. I'm inclined to go ahead and add some.
Next confusing thing: I'm showing a P deficit of 125/acre, but my soil test is showing very
high P - expected in Western Washington. So do I follow what the
local lab sees and don't add any, or add what the worksheet shows? I'm using the Weak Bray number (135 x.44= 59.4) as opposed to NaHCO3-P. I think that's right.
Then there's the K. According to the soil report, my K is 314ppm, which is a medium amount. The worksheet sets my lb/acre at 628 and my target at 395 - so it's way too high!
There's a similar difference of opinion in the Mg - the soil test shows 335ppm as average, but the worksheet (16.7 x 240 x 0.12) puts my Mg in the substantially too high range.
About the only thing I'm not confused about is Calcium. I haven't missed the point that I'm rebalancing an out of whack system... I just expected the soil lab to underestimate the level of elements necessary for good nutrition, but it seems like the worksheets want me to have way less - except for P. The P question is really leaving me frozen in my tracks. I'm convinced that I'm doing magical math and screwing it up completely.
Someone
should start a cottage industry doing these worksheets! Any help you can offer will be greatly appreciated. I need to plant some
trees and I really want to amend the soil first. My garden isn't doing well at all.