Living mulch, soil compaction and no-till

Hey all,

I have a question. I have a heavy clay soil. I will use compost and biochar mixure to amend it hopefully make it better. As a (living) mulch I want to sow subterranean clover and use it as perennial. The question, will the roots of the clover be enough to keep the soil loose, so-that I don't till it? I hope to make the clay much looser with the compost and biochar but I am trying to incorporate the no-till system.
If not with subterranean clover, maybe you guys have some suggestion? Open for it.
Thanks in advance.
I wish you all (in the northern hemisphere) happy gardening season.

Have you thought about a green manure crop that has a range of plants that break up the soil?

Hello Vase,

I think that Subterranean Clover will work nicely to break up that clay soil, but it won't do so immediately.  I second what John already said about planting a mix as different types of plants can get to different root zones, grow at different times of the year, etc.

I do have to ask though, what is your ultimate goal?  Do you want to turn clay into a softer loam just to do so or are you planning on gardening there or some other type of planting in the future.  The reason I ask is that this will partially determine what type of cover crop will work best.

Good Luck, and I would love to hear your long-term goals!

Eric

John C Daley wrote:Have you thought about a green manure crop that has a range of plants that break up the soil?

Such as? I am not that experienced gardner, please help :)

Eric Hanson wrote:Hello Vase,

I think that Subterranean Clover will work nicely to break up that clay soil, but it won't do so immediately.  I second what John already said about planting a mix as different types of plants can get to different root zones, grow at different times of the year, etc.

I do have to ask though, what is your ultimate goal?  Do you want to turn clay into a softer loam just to do so or are you planning on gardening there or some other type of planting in the future.  The reason I ask is that this will partially determine what type of cover crop will work best.

Good Luck, and I would love to hear your long-term goals!

Eric

My ultimate goal is no-till gardening with clay soil and minimise watering :) it is very hard to grow plants without tilling in clay soil. So, I though that the roots will keep the clay loose and the other plants wont be having that much dificulties rooting and growing healthy.

Don’t mix your organic material in with the clay, but rather build on top of it.  Well fed, the worms and other soil organisms will work the organic material into the clay and loosen it.

If the end goal is to garden in that spot, I have to put in a vote for woodchips for mulch. I think you would see benefits faster than a living mulch. There are quite a few posts on the benefits and limitations of wood chips on permies. Just put "wood chips" or "woodchips" into the search bar at the top and you will see what I mean.

Vase, I have heavy clay soil, and the best thing I ever did was cover it with 4"-5"/13 cm approx., mulch, preferably with wood chips.  Mowed grass/weeds work, but need replenishing more often.  You'll be amazed at how fast the soil absorbs the mulch, so it needs to be maintained at that depth.

Never let the clay be exposed to the sun.

Underneath that mulch put all of the soil amendments you can get your hands on, including some composted manure.

Clay is great soil.  It has minerals for nutrition and holds more water than loam.  If it's too hard to dig, just wet it down thoroughly, cover it for a couple hours, come back and it should be easy to dig.  You probably know that moment with clay soil when it goes from clay to sloppy mud, and in between is when it's at its best.

Vase,

I agree with the previous respondents.  I recommend building the soil up with woodchips.  I did exactly that and it is amazing what happens one year after having a foot of wood chips laying on top of clay soil will do for the ground beneath.  I too have clay soil.  Rather I *HAD* clay soil.  Now my garden beds are a nice, dark, rich loam.  You can still add in things like peas and beans to try to add in some nitrogen and get roots into the wood mix, but it is not strictly necessary.

Eric

FROM; what is Green manure
What is green manure?
Green manures or cover crops describe a range of temporary, fast growing leafy plants which are sown from seed generally in autumn or spring, grown through the next few weeks or months (depending on the season), and then, just before they begin to flower and set seed, they are slashed and turned in to the soil, or used as mulch for whatever’s to be planted next.
Why is it grown?
You might consider growing a green manure crop in a new garden area to supress weeds, improve drainage, reduce compaction, stabilise the area to limit erosion, and improve the soil before you put in permanent plantings. Green manure crops are often used in vegetable gardens, in beds, or parts of beds which are given a break from vegetable production for a season to improve the soil and set the bed up for the next crop.
Benefits of Particular Plants
Different crops have different benefits, and can be grown in combination. Seed sellers will often sell individual seed types and green manure mixes.
Some examples:
Biofumigants, like marigolds (Tagetes patula) planted in spring, brassicas (Brassica napus and Brassica campestris) and mustard, planted in autumn help to control root knot nematodes and root rot fungal pathogens. These crops must be dug in to release beneficial gases as they decompose.
Legumes, like lucerne, clover, beans and peas, which fix nitrogen and will make it available to whatever follows the green manure crop.
Weed smotherers include lablab, cowpea, lucerne and buckwheat.
What plants to grow
Cool/cold season crops:
peas, broad beans, oats, radish, poached egg flower,  
Fava beans, broad beans, tick beans, fenugreek, lupins, oats, subclover, woolly pod vetch, ryecorn, yellow and black mustard seed, other brassicas, feed oats, wheat or barley.
Warm season crops:
Buckwheat, cowpea, French white millet, Japanese millet, lablab, marigolds, mung bean and soybean,poached egg flower, millet, buckwheat,  beetroot and even sunflowers
Seeds
Seed merchnats often sell mixtures of seeds.

Do I mix the wood chips with the soil or just lay it on top of it? If second, what do I do in autumn? Do I collect all the wood chips and then re-lay them in spring?

Vase,

What I did was drop a whole pile of wood chips on my garden bed that had pretty tough, hard, clay soil—certainly not the type of soil that you really want.  That was in Fall.  By spring the chips and soil had already started to merge together.  I took the extra step and inoculated the chips with wine cap mushrooms and really broke down the soil further.

As for planting, I plant right into the chips and get the growth of the chips to help break down the chips.

I could go on and on and if you are still interested, by all means, fire away.  I can point you in a couple of directions.

Eric

How about sawdust?

Yep, if you have a whole bunch, sawdust should work just fine.  In fact, sawdust will get colonized by fungi and microbes even faster than the wood chips.  If you want to add any amendments to the sawdust, it is great as it will conveniently absorb most of the materials you would use so you can spread and use it fairly easily.  If you want to use mushrooms, they should get started even faster than they would in wood chips.  Worms will also crawl through easily.

Do you have access to a lot of good, hardwood sawdust?  If so, you could have quite a treasure there.

Eric

Actualy I do, fresh as well as decomposed, there is a sawmill where I live and I have access to it.
Just to make it clear, in fall I spread the sawdust all over the field, but not mix it in, just leave it a top. Come spring I till/ mix it with the soil, right?
About the mushrooms, I know a guy that sells mycelium for oyster mushrooms, will it work? If yes, how much is enough for a 15x20 meters field? And how do I use it with the sawdust, in fall together with the saw dust, sothat it has enough time to decompose the sawdust?
One more question since I have access to almost infinite ammount of decomposed sawdust, is all of the above necessery or can I just load like 6 cubic meters of decomposed sawdust and spread it all over the field and mix it?
Is there someone more needy then I with all of this questions and supposings?

Ok Vase, here comes the longer post.

For starters, I would pile the sawdust 6”/15 cm on top of the garden bed and leave it there to rot down.  I would not till it in.  As the sawdust rots, it will slowly merge with the topsoil to the point that the two are virtually indistinguishable, at least that is what happens with my wood chips.  The nice part about sawdust is that you can plant small seeds directly into the sawdust.  If you need to, feel free to lightly amend the top of the sawdust to give your plants nutrients as the sawdust rots, but my *personal* thought is to not till the soil—it scares off the worms and generally abuses soil life.

As for the oyster mushrooms, you are asking a challenging question.  For starters, you are talking about inoculating a really huge area.  My garden beds are a bit larger than 2x3 meters (8x16 feet), and I last inoculated with about three 5-pound (2 kilo) blocks of mushroom spawn (I used Wine Caps, but the same principle applies).  In my case the whole bed decomposed roughly equally over the course of one year.  But the price of spawn adds up.  If I were in your situation, I might be tempted to buy about 20 pounds (maybe 8-10 kilos) I’d spawn and inoculate a part of the bed, but understand that the bed will take time for the spawn to fully spread throughout the garden.  Maybe consider making something like a ring or grid in the middle of the garden (maybe make it 2x2 meters? 3x3 meters?) and the spawn will start growing, fully consuming the sawdust in the center first, then spreading out and eventually covering the entire garden.  

I don’t know how long this will take, but I once had a bed 6x32 feet (2x10 meters) heavily loaded down with wood chips.  I inoculated about 40% one year and the next year the mushrooms spread like a slow fungal fire till they occupied the entire bed.  

Just to be clear, my experience has been with wine caps which are pretty bulletproof mushrooms.  They also love to grow on the ground and interact with the soil.  Oyster mushrooms like to inhabit a branch off the ground.  This is not to say that you shouldn’t use oyster mushrooms, plenty of people here have used oyster mushrooms on wood chip piles, but the exact growing patterns may vary.

Either way, mushroom compost is amazingly fertile and you might find that after a year of composting with mushrooms that you don’t need to add fertilizer any more.

If you are still interested after all of this I can direct you to a long-running thread I have detailing my experience (good and bad) with growing mushrooms).

Good luck!

Eric

Thank you a lot, it was very informative post. I will try to make garden beds in the field, right now I work it as open field, no beds. I saw many designs and I will build some beds.
Any opinion on the decomposed sawdust?

Use that decomposed sawdust!

Maybe make that your first layer next to the soil.  Mushrooms won’t grow as well in it as it is largely decomposed already.  Alternatively you could just mix it all up with fresh sawdust and get the rot started faster in the fresh sawdust.  Wine Caps would be ideal mushrooms here, but I am not certain about oysters mushrooms.  They might work, but I have not tried it, and oyster mushrooms prefer more pristine conditions than a bunch of rot.

Eric

Vase,

Just to let you know, I have a long-running thread about mushrooms and wood chips HERE:

https://permies.com/t/82798/composting/composting-wood-chips-chicken-litter

This might be helpful.

Eric

THANK YOU ALL!!! You've been all much help. I appreciate it a lot. Thank you tausend times.

I agree with Eric.  You don't want to mix in saw dust or wood chips.  You could mess up your carbon to nitrogen ratios and set back your soil, just like you would set back your soil if you put uninoculated biochar right into the soil.  Leaving it at the surface is the way to go. The sawdust and chips will age and rot over time, with the help of fungi, microbes, worms, and insects. When it is ready to be incorporated into the soil, worms will physically bring it down, tiny bit by tiny bit, at night. That is their job, and it is their role in the ecosystem.   As it passes through the worm, it will become useful to the soil.  Having some fungal content in your soil is crucial for bushes and trees.

John S
PDX OR