crossposted from Reddit:
hi all - my wife and I are doing our best to amend our terrible soil in climate zone 6b/7a (western Colorado, near the Utah border). our logic and philosophy is that at this time we can only do what we can do, so that’s making our home as solarpunk and permaculture-centric as possible right now (without losing sight of building collective resilience and empowering the disenfranchised).
to that end, our soil: it’s pretty abiotic. to grow food, which is a future goal, we need healthier soil. also we’re not flat broke but we’re relatively close; being frugal and cheap is a necessity. so we determined that we’re going to try to amend our soil using cheap, locally sourced, and recycled things - and maybe more sweat equity than I’d love, ha! we elected to go with the lasagna method.
the lasagna method is to lay down different strata of materials to encourage the breakdown of “brown” and “green” materials, in composting terms. also our yard currently is mostly dirt with a few weeds for good measure, so even if we eff it up, it’ll be okay.
I work in IT and my wife’s a librarian, so we have access to a LOT of cardboard. I’ve been collecting it slowly over the summer, and today we decided to lay down our first layer.
here’s the plan: lay down a layer of cardboard (brown only, tape and labels as removed as possible) two sheets thick. soak the cardboard so it doesn’t blow away in the wind. cover that with a layer of wood chips, which we happen to have from removing a tree along our fence line with our neighbors and chipping it up. the wood chip layer is about two to three inches thick, and then we soak that, too. finally, we cover the wood chips with a layer of greens; for us, this is getting on our local Buy Nothing group and asking for lawn clippings. we are also going to plant fall cover crops and once they have grown in the spring, do a chop-and-drop layer of that.
over time, we will plant a few trees (looking at either a local growers apple variety or a multi-graft we can buy online) and have a rotating group of garden beds.
so that’s our plan: a bit of couples labor each weekend over a long period of time, with the hopeful result of improved soil biology and then the growing of native.plants and flowers and food crops.
I hope this is solarpunk enough to warrant this post!
good growing to us all.
I don’t get the permaculture sphere’s raging hard on for cardboard. Soils are my area of expertise, and the whole thing has me scratching my fucking head. Cardboard has a high C:N ratio, so right off the hop you’re setting your system up for N immobilization.
But it breaks down fast!
This is because it’s not very durable and quickly turns into small particles which are more rapidly acted upon by the microbial community. I get using it as a mulch, if you have literally nothing else, I guess. I would probably just till instead. Further, the 2-3 inches of wood chips they want to add would be sufficient to choke out weeds without the cardboard.
But wood chips also have a C:N ratio!
True, but their particle size is much larger, making them decompose much slower than cardboard. If you were to use sawdust (don’t; C:N 500:1 to 1200:1 or more!) as an amendment, you would be in the same situation as cardboard, since it’s very fine and has more surface area for microbes to act upon.
Ok, genius, what would you do?
Assuming you want a garden and don’t want raised beds:
- Soil test for nutrients, salinity, and metals. If good, then move to step 2. If not, raised beds. End of discussion.
But what about phytoremediation?
Generally not worth the effort, you still have to dispose of your contaminated plants, and they usually only hyper accumulate a few spp. Of metals.
- till the shit out of my existing soil. This is likely 3" max of poor quality topsoil, underlain by compacted subsoil. Till to about 30 cm (or more if you can).
but tillage = bad.
Generally, yes. But this is shit soil to begin with and In this case we want to maximize soil drainage.
But I am worried about weeds
Don’t be, we are gonna bury the mother fuckers. Tilling will also help with this.
- Find any suitable compost or organic amendments I can with adequate C:N ratio. These are things like leaves, grass clippings, coffee grounds, composted manure. Soil test them to screen for things like salinity, pH, SAR, and metals. Apply heavily. Try and get another 10 cm or more of soil depth. This is going to be our growth media.
Now we have 40 cm or more of reasonably well drained soil, that’s high in organic matter. Time to plant. Manually pull weeds as needed, or hoe (if you’re ok with tillage).
What about this snake oil I’ve got sitting in my garage that I bought at the recommendation of some guy on FB?
Toss it. There are a lot of amendments out there. There are also a lot of quacks. I saw a guy pitching ‘soil homeopathy’ on a permie group. Another guy was going on about electroculture… I can’t talk about this, or I’ll have to take another dose of my antidepressants.
Anyway, sorry if that was ranty, but I really like dirt.
nah, go for it; i readily admit to knowing only what i have googled so far about things. i’m using cardboard because it’s what i have; i am also composting, but buying stuff is out of the realm at the moment. glad to hear that tilling isn’t necessarily all bad; tilling = bad is what got me on the cardboard thing in the first place.
i do appreciate the heads-up!
Using what you have is the essence of solarpunk.
And nature is forgiving. Your garden doesn’t have to be perfectly optimized in terms of chemical ratios. Organic stuff in soil = good.
Sounds like a really good plan!
We also have soil that isn’t very conducive to growing. We used the same method about two years ago and are starting to see results. We still ammend the soil a bit when we plant directly, but there sure is a lot more going on in the soil now. It’s super satisfying to see mushrooms popup in the wood chips!
If you ever find yourself with small logs or large branches, I recommend looking into Hugelkultur, which similarly involves building mounds of compostable organic material around large pieces of wood, which allows for the slow breakdown and release of nutrients over time
I might add a little compost to kickstart the breakdown or all that organic matter but sounds like a great plan!
I would make sure to look at the C:N ratio of your various layers to try to end up where you want. If it’s unbalanced it can cause problems.
I would just do the cover crops along with some nitrogen fixers for several years.
PS – I would keep getting the lawn clippings and use them to mulch my plants.
Are you working off any guide, or mostly improvising?
basically we googled lasagna gardening/lasagna compost, and did some research on the soil in our area. once we got our head around the basics we just started using what we had on-hand.
I may be way totally out of my depth, so if this sounds wrong, someone correct me. But my thinking is that if you want to create soil, one key consideration would be to try to make sure that the input has the same elemental composition as soil, since the microbial digestion will proceed until the microbes run out of something. So if you have a ton of cardboard, which is mostly carbon, then the digestion will proceed until all nitrogen present is depleted, and then whatever wood chips and cardboard is left will mostly sit there undigested, but won’t be broken down until the microbes get more nitrogen.
The target ratio, I believe, is probably pretty close to the Redfield ratio: 106 parts Carbon: 16 parts Nitrogen: 1 part Phosphorous.
From what I see online the composition of wood and cardboard is mostly carbon (plus oxygen and hydrogen, but these aren’t nutrients), with very little nitrogen or phosphorous. So for every 6.6 lbs of cardboard or wood chips you use, I think you’ll want one pound of nitrogen and one ounce of phosphorous, just mixed in, either as pellets, or powder, or dissolved in the water they’re soaked with.
Again, this is all wild speculation. If someone thinks this advice is bad, speak up, I don’t want to misinform anyone.
Relatively on the right track, I’d up the nitrogen some so it isn’t all tied up in the microbial process, but things will grow
