Organic soil re-use

[Anesthesia]

Hi folks,

I have been growing for a number of years (autoflowers), all grows done in organic soil and the majority under 250w CFL's.

One thing I have always looked out for are signs of mineral deficiency and plant issues, particularly the signs of using excess nutrients resulting in the browning of leaf tips.

I've never had any serious nutrient deficiency issues - throughout the grow the leaves are always a healthy green and by harvest apart from a few yellowing leaves (constant colour throughout the leaf and not spots, which I have always put down to light deficiencies and natural plant age) near the base, the rest of the plant is still healthy green.

Does the fact that the plant is green and healthy throughout the grow indicate that the plant is basically doing well, growing as it should, and the balance of everything is just right?

My feeling has always been that if the plant shows no signs of mineral/light/water deficiencies, and no signs of mineral/light/water excess, I shouldn't be doing any more or any less than I am and "kill it with kindness".

As I am not after a cop-winning plant and prepared to try squeeze every possible bit out of it, is this the "target" that an organic soil grower should be happy with?

The main reason I ask is that I re-use my soil, and at one point I was using soil over 3 years old.

It would be topped up with small amounts of guano/fertiliser/bone meal/nitrogen/plant waste in between grows. During the grow nutrients would also be added from whatever feed I was using at the time. By the time the grow was over, the soil from the previous grow had been kept moist and kept in a container to "cook". I'd then use that "cooked" soil for the next grow, treat the soil from the most recent grow, and so the cycle would repeat.

During this entire process not once have I had signs of cal/mag/nitrogen etc. deficiencies that seem so common in the troubleshooting sections of grow sites.

So in a nutshell, should I be satisfied that I am doing things right, or are there other factors to take into consideration when re-using soil that I might be missing even if the plants are healthy green and growing just fine?

 

[NOOOBIENOT]

like they say if it isnt broken dont try to fix it , organic soil only gets better with age , add some compost , worm casting and some of the other items you mentioned let it cook for 2-3 months and it will produce another great stress free plant , commercial growers worry about yields , organic growers want flavor ,taste, smell , and less stress on us to grow .

 

[bobrown14]

You're on the right track.

I have 1 question you mentioned ;

"During the grow nutrients would also be added from whatever feed I was using at the time. "

What are these "nutrients" you mention??

I've found running AUTO's in organic soil they don't grow very large at all. So I have to grow a bunch of them to get a decent yield.

I've been re-using my soil over and over.

There's a method of growing called "no-till" this can be done in your garden outside as well as in containers. Look up how that process works.

Regarding your plants never changing colors during the grow. Most of it is genetic.

There's a thing plants do called "senescence" - is the process of the older leaves turning colors usually yellow/red/purple etc as the plants leaves mature. This process is completely natural and should be happening with all plants. So leaf color change going down to harvest is a good sign and expected.

I use my soil over and over, I don't leave it sit. The reason is the microbes need roots to stay alive.

If you want to let it sit suggest growing a cover crop (no-till methodology) of say clover as an example there are many cover crops. These can be grown alongside any cannabis plant as the plant get larger the cover crop will die back.

Compost all your green kitchen scraps and use that compost as your soil amendment. Can add in your meals or whatever amendments you are adding to your soil, you can add into your compost heap. The micbrobes will break them down (your "cooking" process you mention) and when you add your compost to you soil as an amendment all those goodies in your compost are ready to be used by your plant. Go easy with Nitrogen and heavier with Calcium sources for cannabis.

Suggest getting a soil test - this will tell you everything you need to know so there's no guessing.

Soil tests are a common thing for gardeners and farmers. In the states its basically free in most states from our local County Extension Service, the soil test is paid for by the AG Bill.

 

[Anesthesia]

Thanks bobbrown14

I'll go into some more detail then as maybe I can pick up some pointers if/where things could be improved.

I'm not after yield - I fall into the "less stress on us to grow" category NOOOBIENOT mentioned.

It's a closet grow - just 4 weeks ago I switched from 250wCFL to 250-600w HPS after many years and saw a huge difference in growth. Coming into summer temps were an issue though so I have moved to 2x HLG QB288 Quantum LED setup which I'm loving.

I'm aware of "senescence" (now I know the right term for it - what I am referring to is throughout growth there is no discolouring/curling/spotting/drooping/crisping of leaves etc. The plant just generally looks healthy until harvest. Leaves may change colour due to senescence, but I've always taken that as expected.

My original soil was basically a compost/peat base with perlite and some amendments added. This kept getting reused as I explained and amendments would be added in between grows - nothing scientific, just a bit of guano/bone meal etc

I'd throw plant clippings after harvest in there, which after a few weeks would have been broken down as well as root balls and occasionally small amounts of kitchen greens. The container is probably about 10-15L in volume.

During a grow I have tried various nutrients over the years as knowledge grew or if I wanted to try something new for a comparison. Miracle Grow, Tomorite, some FoxFarm-type nutrients etc.

So as you can see from the above, it's by no means a scientific and heavily thought out mix, but it's worked for many years and as I say, I have never seen the discolouring or problems I've mentioned above unless I have knowingly done something like overfeeding during a grow.

This is why I am asking whether by seeing a healthy plant doing what I have been doing, am I right in assuming the plant is in the "green zone" ie. not under nor over-nourished. I'm sure it could be better nourished, but if I know my base mix is doing the right thing by doing what I am doing, I can look at improving that accordingly.

I did wonder after posting about nutrient lock as it can be difficult to identify, but I would think if my base mix was an issue it would soon start showing in some form.

I'm not looking for the super-duper-soil recipe nor will I be testing the soil considering my setup, but if I learn that one of the actions above is severly impacting my grow even though it looks healthy, it would be useful to know.

 

[bobrown14]

Sounds like you're doing the right thing. I grow basically the same medium Peat/compost based home made soil.

You also seem to be someone that likes to understand stuff - how stuff works. With soil science it starts with the soil and a test. Hard to say whats coming down the road without the knowledge.

I re-use my soil and get it tested annually same as any farmer does.

If it aint broke thing works until it doesn't. The way to "fix" is with knowledge and science.

Instead of fertilizer I suggest Kelp meal and worm castings. The fertilizers that you mentioned can actually ruin your soil over time. That and Miracle grow... well there's no miracles in gardening and that stuff is made by Scotts/Monsanto. Those fine folks that bring us Round-up among other poisons in the name of ..... greed. So there's that.

 

[Anesthesia]

I certainly do like to understand stuff and how it works. I'm not a TLDR: person

I'm curious about the soil testing - is this something your do yourself, or is it sent to a lab?

I'm pleased that I've been doing things right - funnily enough the reason I'm here is because I've been considering adding worm castings, but it made me wonder about the soil re-use question. I'll definitely be picking some up. At the same time though I'm also hesitant about buying dirt-based amendments as how can I be sure I'm not just getting a bag of dirt from grandma's back garden?

I guess this next question is the type of thing that would be answered by doing a soil test, but out of interest with organic soil, if for instance you wanted to raise the potassium levels, would doing something like mulching a few banana skins and adding them to the medium have any effect?

Any suggestions for an all-rounder feed that won't affect the soil over time? I know there's organic options like aerating and brewing teas etc, and even though I've played around in the past with them a bit, I want to keep it simple.

 

[Big Sparks]

Kelp meal would be one of the best all rounders that you could add to your soil. But ol' Bobrown knows much more than I when it comes to organic soil and using amendments and additives.