@kratos015 On first thought, my concern with rice hulls would be that they might steal nitrogen from your soil while breaking down. I'm not sure how easily they decompose though with nitrogen sources available around them. Perhaps it's like peat moss and coir and holds up a long time. I have no experience with rice hulls, but I'd probably carbonize them first if using for drainage purposes.
In the Philippines, most growers just dump it in giant piles on the side of the road to rot and waste, but one guy I know there is right into more modern agricultural techniques and I got to see his DIY rice carbonizing setup and it was really cool.
This is definitely a cause for concern, and something that we no-till/living organic soil growers should be familiar with.
This is why its a good idea to have plenty of nitrogen in your soil.
You don't just need nitrogen for your plants, but to facilitate the composting process as well as to provide energy to the microbes putting in all of the work. Nitrogen = energy. This is why mulch can potentially cause issues if you don't have enough nitrogen in your soil. The mulch will leech nitrogen from your soil to break down (C:N reaction). If you have cover crops that are nitrogen fixators, or you keep on top of your top dresses, you'll never experience this issue.
I've no experience with Rice Hulls, personally. I've heard from many people that use them that they decompose within a year, at best. Great if you're a ROLS guy, but not so great if you're a no-till guy. Rice hulls are in fact carbon, and not nitrogen, so they'll decompose within a year in a good quality living soil. Not just that, but in my experience, unless you live near a brewery rice hulls can be pretty pricey. They provide tons of silica to your soil, which is awesome, but simply not worth the cost IMO. Perlite has remained the industry standard for decades mostly due to its cost effectiveness. If you can get pumice for cheap, pumice is the best. But $20 for 4cuft of perlite is very tough to beat.
What exactly does carbonizing the rice hulls accomplish? This is the first I'm hearing of this and I'm very much interested in hearing more.
Everything I've said about Rice Hulls, I think the absolute best use for rice hulls would be in a worm bin. But again, I don't live next to an affordable source of rice hulls. Until I can find 4cuft of pumice/hulls for $20, I'll be sticking with perlite. Even for a worm bin.
That's interesting. Are the rice hulls carbonized for living-super soil dressings/mixes?
@Op. Lots of useful ideas here with what the problem could be. I see a pH issue witch in turn lead to more issues with nurtirent uptake etc.
In my experience, most of the time a pH issue is the result of overwatering. Consider how powerful of a buffer dolomite lime is, and the fact that it is in practically every and any soil mix. If one has dolomite lime in their soil, and is still experiencing abnormal pH conditions, this is almost always the result of overwatering. Overwatering results in a lack of oxygen. No oxygen = anaerobic bacteria. The result of anaerobic bacteria feeding on the amendments in your soil = ammonium gas. Ammonium gas has a pH of ~11-12, which can easily override the dolomite lime/buffering agent in your soil.
Aeration must be it then.
I'm 100% with kratos that it's a pH problem, lockout, roots, or a combination.
Aeration is generally most important for all.
Out of curiosity, how did you come to the conclusion your soil's pH was 7. How did you test it to reach that number?
If you tested it properly and your top soil is 7,
then down the bottom could be much lower..
Also the bottom and centre is likely staying soggy longer than the top soil. Especially if your soil is heavy.. If there's root rot anywhere, that's where it'll be.
Looks like pH problems and root disease, caused by overwatering and lack of aeration. (in my honest opinion)
One thing to bare in mind too, is, if your soil's heavy, overwatered, or lacking aeration.
Then rich organic matter isn't necessarily a good thing, including your microbial tea.
If your soil's environment is ripe for anaerobic bacteria and conditions, then your aerobic bacteria is being out competed. Aerobic tea will effectively be food for the anaerobic environment. It's balance which is most important.
If you're also finding you're having to water too often, because the top soil's drying out too fast. Add a layer of mulch to your top soil.
Good luck. All the best.
Aeration is a huge deal. I eliminated the bulk of my problems by running 40% perlite in my base mix instead of the usual 30-33%. One can always top dress with compost. However, one cannot top dress with more perlite and/or peat.
As for the bottom/center staying soggy, this confirms an issue with a lack of aeration/drainage. The magic of peat and coco is the fact that they act as a "wick" for water. So, if one has dry soil on top and wet soil on the bottom, this leads me to believe the soil is already compacting so much (due to lack of perlite) to the point that the wicking action cannot take place.
As Aussie says, in an overwatered soil rich organic matter will actually be the death of you because you're effectively feeding the anaerobic microbes instead of the aerobic ones (the good guys).
You ever had soil smell like a combination of rotten eggs, dirty feet, and diapers? Ammonium gas. The byproduct of anaerobic bacteria. As Aussie says, even worse than the aerobic bacteria being out-competed.. they're actually being devoured and eaten as food in conjunction with the organic inputs in your soil.
For those of you that are still in veg, this issue can be remedied by transplanting into larger pots with extra perlite added into the mix. If you're in veg, you can always up-pot into soil with extra perlite.
Unfortunately, if you're in flower you're just kind of fucked and you have to let things ride.
This is why I run a base mix of 40% peat/40% perlite/20% compost. I top dress with compost constantly, because it is an option. I cannot top dress with aeration, however.
Hydrogen peroxide may be a decent solution for dealing with root rot (because it adds oxygen to your soil), however this isn't something you can do on a consistent basis because too much H2O2 will wreak havoc on the microbes within your soil.
Consider a human being, microbes are no different. In order of what is most important? Air>Water>Food