Recycled soil that requires no additional nutes?

[bakelite]

Here’s my story. Like many people here at ICMag I’ve been messing around on the side with reused soil on and off over the last few years now. I have been cutting up my old plants (stems, trim, dead leaves, males, roots and all) and letting everything compost together over the period of 2-3 months before I tried using it again.

After the 2-3 month hold, I would then add various amounts of guano, bone meal, kelp greensand etc before I used it again. The amounts used varied ranging from 1.5-3% on the recycled soil. I wasn’t having much luck and was consistently getting what looked like burning and/or lockout issues with plants that were grown in it. All of the plants eventually grew out of it during flowering, but obviously these results were less than optimal (i.e. leaves fell off and/or were crispy etc.).

Recently, just for the hell of it I tried put a clone in the reused-composted soil straight without any amendments at all (I know, I should have tried that at the start). Much to my surprise the plant looked absolutely fine with vigorous growth and sporting nice dark green leaves top to bottom and no signs of deficiencies at all. The clone looked identical to the one (clone from the same plant) next to it that was growing in amended new organic soil (Happy Frog).

Obviously I am happy as I have a bunch of this stuff lying around and won’t have to buy any soil for a while. The only thing that I can figure is

A) The soil was not completely depleted when I recycled it

B) Any nutes that hadn’t broken down during the previous grows were now available for the plant to use due to time and microbial activity.

I am now experimenting with fine tuning this reused soil by adding organic ferts albeit on a much lower levels than I was using before (~0.2-1%). Also I am tracking the soil and keeping the 2nd pass separate from the first.

Anyway I just thought that I would share what I have learned about recycled soil over the period of last last few years with everybody. It is the least I could do after all the knowledge I have gained here at ICMag over the years.

Questions, Suggestions and Comments are welcome!

-bakelite

 

[MrFista]

I think you just pointed out a way to know if your soil doesn't need any more amending. When the plants first start looking hot lay off the amendments for a run. Some of this stuff is long term. You can fix arising problems with teas and amendments in them if needed.

When I saw how much amendments go into a basic soil formula like used here in organics forums I was amazed at what the plant could take. Thing is, only some of that was being used, the mix was working well as the large volume of additions provided surface area sufficient for the grow to proceed at a microbial level. The nutes, even if they were actually depleted during a run, still had plenty of reserve locked up in the biomass of the soil inhabitants which would have increased greatly as the plant biomass increased. Adding the same nutrients then, to a second run with a now large existing microherd, could tip the system into excess, right there on the second run.

I use char in my mixes as it (is said to) reduce the need for ferts, and then I add lots of compost, again reducing fert needs, and castings...

Now I've added a mulch, dead leaves at first, but on Jaykush's suggestion am using dried weeds in the mulch too to add nutrients in this manner. Almost don't need ferts anymore but the soil was loaded up over time.

People grew with compost alone for a long time and did well at it. We have the best of both worlds now, science and organics, normally though, one gets ignored at the detriment of the other.

I now use designer type products in compost teas, which works out to be extremely economical, and results drive the motivation to do this. Barely any 'products' need go in my soil anymore.

 

[bakelite]

large volume of additions provided surface area sufficient for the grow to proceed at a microbial level. The nutes, even if they were actually depleted during a run, still had plenty of reserve locked up in the biomass of the soil inhabitants which would have increased greatly as the plant biomass increased.

MF,
I hadn't even thought of that. I read "Teaming With Microbes" about 6 months ago and much of it is still sinking in

-bakelite

 

[Rose56]

Last year in the fall before the rains I took the used soil from my container grows and spread it over an area I had planned on using for an outside grown. My thinking was any left over nutes would soak into the ground with the rains. The grow I planted there this spring are growing like crazy.

 

[bakelite]

Last year in the fall before the rains I took the used soil from my container grows and spread it over an area I had planned on using for an outside grown. My thinking was any left over nutes would soak into the ground with the rains. The grow I planted there this spring are growing like crazy.

Rose,
Reduce, reuse, recycle......excellent! Prior to what I have seen using recycled soil I would have thought that most of the primary elements (N,P&K) would have been sucked up during the first run. I would have thought just some select secondary and and micro nutes would have remained in the soil. Luckily I was proven wrong.

Now I just have to determine what I need to amend with in order to make it like new soil (the plants in the unamended reused are just now beginning to show deficiencies, I'm guessing Nitrogen and perhaps possibly Iron). For the first 3 weeks or so the plants looked excellent! And they more than doubled in height during that time.

-bakelite

 

[SecretGardener]

MF,
I hadn't even thought of that. I read "Teaming With Microbes" about 6 months ago and much of it is still sinking in

-bakelite

Great book! And you're right it really does take time/experience to sink in. I read it just before my first organic grow (in progress now) and I am going to read it again after my first organic grow to really pick up on the stuff that didnt 'connect'

 

[santasapimp]

are you letting the nutes you ad break down?

let your waste (trim males ect) break down, then add bone blood ect, wait ANOTHER month or two for those to break down. when you plant clones into this they will explode