Odd soil test results, chasing the mix again.

So I just got my latest results back from the new mix. I knew going into it this mix may be a little off given the recycling so I was assuming I needed to load up a bit of N as prior test showed that as very low. I was also very low in P. I added a lit bit of neem, alfalfa and some other low N inputs but nothing I would expect as being a 'heavy' load.

Now the surprise this time is that the P level is still very low. The source I used this time was Roots Organic and their Seabird Guano; I used both the powder and pellet form for some quick release & some slow release. So the test shows my P levels as extremely low still! I was afraid of overdoing things so I didn't use more than 1/4 cup of each or so for total of 1/2 cup for each tote full of medium. Each tote is probably around 12 gals of media.

I'm now trying to figure out if the test could be 'off' here. I looked at the Mulders chart & another little cheat-sheet I've found online in the past and I was expecting to see that maybe too high or too low of some macro element was skewing the test result. But what I didn't see was anything that would cause a very low reading for P itself.

Anyone know what could influence the P level to read lower than actual? Before I go putting more P into the mix trying to balance it (yet again) I wanted to rule out anything I'm not thinking of. I think if I cut the medium with something inert to deal with the high N level I can then bring the others up to ideal levels.

That's the 1 thing with organics and soil recycling is you can end up chasing things; Using fresh new mixes based on a proven recipe does have its appeal in that regard. It's wasteful - but it's consistent and repeatable.

I had placed 4 plants into this new mix and 2 were fine then suddenly tanked on me turning wilted and grey basically. The other 2 were planted about a week later but they've survived so far and might be starting to show signs of taking root & starting to recover & grow again. But now that throws my plans off as I had laid out my space based around 4 plants going in and being of same size/starting point (very old clones that had been sitting with established rootballs)

Argh. I l love the SIPs + Organics but the soil mix chasing deal does provide some frustration. Purchased some new bags of NFTG #4 to use in toning it down along with some peat & coco I have on hand. We'll see - wish these soil tests turned around a bit faster.

Here's the results from this batch. At least my micros are up a tad bit - not sure if that came from my EWC or Compost inputs. I was looking into how to use borax to get the B up a bit. For the others I have Big6 but planned to do foliar feeds for that as my sulfur is already high.

I was looking at some cheat-sheet where they have K:Ca:Mg ration as 4:2:1 so I was looking at raising my K a good bit and definitely the P level if this is to be believed. I'm just floored that I put in 0-11-0 guanos and it didn't seem to really register much.

Thought about flushing to get N down but then who knows the impact / imbalance of others that would occur. I think cutting the mix with something inert and then raising P & K might be my move. Curious what others would do here? Not looking to fry my current clones as I was hoping to get a winter run going asap.

Not sure if this was your point, but that article did lead me to think about it... I might have P in the medium, just not in available form. Which those Soil Savvy tests are oriented towards what is available. Sort of leads back to the Mehlich test being useful still.

Really to get the full picture you need to know what's available and what is present.