I got a cheap NPK test kit and the results say that my spent soil still has surplus N, surplus P and adequate K. So I stopped watering in fish hydrolysate and started using more blackstrap molasses. I backed down the chicken manure in the recipe and increased kelp meal and greensand. PH was good ~6.8
I also ran a test with a bag of Fox Farm Ocean Forest. The ladies in FFOF vegged up nice but immediately starved in flower and needed emergency potting up. The FFOF soak test showed 600 ppm TDS while my cooked soil is about 900 ppm TDS. My spent soil ranges from 550-750 ppm TDS.
I've always been a massive advocate for LOTS of aeration in organic soils, especially the mixes predicated on compost or castings.
i run nearly 50% aeration, and i have literally 8 types in the soil.
each doing different things
i found a REALLY good site regarding organics and techniques employed for container plants
it's easily the most comprehensive read I've found in regards to a properly constructed soil mix
check it out, it's worth reading, even if it's all stuff you know.
http://organicsoiltechnology.com/subsrtates-and-soils
i admit i'm confused about the TDS readings you guys are taking, in an organic mix all that is going to change massively, especially if you are adding teas and water soluble nutrients, not sure what the advantage is of that test?
but i am phrasing that as a question because i'm not sure if it's for another reason or not?
just in my mind i'd say the only time you'd wanna do that would be if you had excess runoff or whatnot and you were trying to anticipate the availability of the nutrients and such, but past that a TDS test on an organic mix is going to be fairly misleading, no?
sorta the same thing with the NPK test too, much of the nutrients won't be detected in that test at all, an example would be that greensand you are adding..
also remember that much of the nutrients is sequestered in the organic material you have in there, the humus/peat and whatnot, even furthermore the availability of those nutrients is mostly predicated on the microbial interaction, and not even made soluble until they interact with it
testing your soil for soluble NPK with these little kits in organic growing is sorta not really applicable
because in true organics nutrients are soluble for very short periods from microbial interaction before they are uptaken by roots. Otherwise they are sequestered in organic matter/humus and cannot be detected by such tests.
or even still if it's a form of slow release nutrients it won't even be "there" (bioavailable or detectable) , examples are bone meals and rock phosphates, crab meal, etc
This is why NPK ratings on compost are so low but it actually could contain potentially more nutrients over time than a typical chelated salt nutrient would.
I'm only mentioning that because it'd be frustrating to make adjustments based on the test results, and have that create an issue or exacerbate an existing one.
make sense?
