Help w/ Soil Improvement Using Cover Crop?

Hello everyone.  This is my first post on this forum (which I heard referenced in one of the many Permaculture videos I've been watching).  I am not an experienced gardener, and even less experienced with Permaculture principles (reading a lot, though).

I have a couple of questions that I hope you can address...  but first a quick background.  I have an area in my back yard roughly 3000 sq. ft.  I did exactly what everyone recommends NOT doing: allowing bare soil.  As you can imagine, this area has been overrun by various types of weeds (only a few remaining patches of Centipede grass remain).  The soil is quite poor...  very little useful topsoil (mostly eroded), followed by mostly sand, ending in very dense soil (clay?).  My intent is to garden in this area after improving the soil quality.  I already have various young fruit trees there (probably a foolish decision, even though I amended the soil in and around the planting area).

My intent is to "sheet mulch" the area with cardboard, add compost/mulch, and broadcast Sorghum Sudangrass (I'm in Zone and intercrop clover (and possibly even annual Ryegrass).  I even have Sunn Hemp seeds as an alternate legume.

My original question was...
[1] if the roots of the Sorghum Sudangrass (and other cover crops) can penetrate the layer of 1/4-in cardboard (obviously, at times overlapping to 1/2-in).

After thinking about this, I might as ask if...
[2] there is a better alternative to dealing with weeds prior to broadcasting the cover crop.  Is cardboard even required or will the cover crop outgrow the weeds (none are taller than 3 inches and most weeds grow close to the ground... I killed the rest manually).

I apologize for my ignorance, but am anxiously willing to learn.

hi Daly,  welcome to permies

my recommendation would be number 2

cardboard is usually used to hold back grass and weeds so another crop, such as garden veggies can get started
with cover crops this shouldn't be needed
I would spread any compost/soil you have  and then sow any and all of  whatever seed you had into it
this will increase the chances that something will take hold,
if all of them grow, so much the better

before and after pictures are always welcome

good luck

As Duane mentions, number 2 is a far better choice for your situation.

Good amendments to improve soil quickly are things like;
Wood chips or finished compost applied as a top dressing.
Bone meal will help by adding calcium to the soil and that can help make the soil looser for better water infiltration.
Gypsum is a great way to get clay soils to break up faster and can be bought or found as left over pieces of dry wall board at construction sites.
Gypsum also will help with water infiltration.

For plants that will help you create good soil fast try Daikon radish, Rape, Alfalfa (Lucerne), buckwheat, Clovers for a good cover crop mix that will increase the humus in the soil when you cut it down for a mulch layer.

Nature like diversity, so the more different plants you seed, the better that soil will become in a short period of time.

Redhawk

Thank you, Duane and Redhawk!  Not only did you save me time and effort (laying down all that cardboard), but you highlighted my mistake.

I will take my "before" picture tomorrow and post it.

Oh, one other question... Do you think I need to turn over the patches of remaining centepede grass, or can I just broadcast the cover crop seeds on top?

Having lived in NC and GA, I have dealt with a lot of heavy clay soil with bare patches and weeds.  Actually, it may have been worst when I lived in VA, because it was also full of stones.  My advice is to not worry about cardboard and sheet mulch to start with.  Use what you have and add to.  First, aerate with a pitchfork.  Use your foot and dig the tines in as far as you can - pull and push to open up the soil... little hole on tope, lots of space below.  Broadcast clover and/or alfalfa or another good nitrogen fixing soil improving ground cover.  Chop and drop with a scythe. DO this just before a rain if possible.  The clover and alfalfa will find those holes and come up thickly.  Let it grow up... chop it. Let it grow up... chop it.  Sow more stuff - comfrey and other deep rooting thing between chops... and daikon radishes, or anything along those lines that will break up the soil.... and beans, peas, etc.   Every time you chop and drop, you are building mulch/topsoil as you loosen the soil.  Do that for a year... be sure to sow some stuff you can eat, so you can enjoy being on the land.    Then, re-evaluate the land.  Do you need more mulch?  Straw?  Chickens?  Do you still need to sheet mulch after a year of building organic matter and incorporating it into the soil?  If so, now it is ready.  In my experience, after doing the above..... very little more needed to be done.... just continuing soil building.  But, I have moved around a lot and my experience has been on smaller parcels that can be intensively managed. .  I have yet to be on large property long term.  I plan for that to change soon.

Daly Gutierrez wrote:this area has been overrun by various types of weeds

Sounds like a beautiful cover-crop to me. Ideally suited to your climate and soil. Self-replicating. Generates lots of biomass.

Can't thank you guys enough.  Thanks for the additional feedback, WJ and Joseph!  I'm going for it this weekend, guys...  I'll first take pictures, then aerate a bit, maybe throw some free compost/mulch, and finally broadcast the cover crop seeds.  Oh, just thought of this...  do I need to buy straw or hay to cover the seeds?

Probably not.  When you chop the existing growth, it should provide some mulch.  If, however, your ground is very patch/bare, some additional straw or leaves would help.

Some aged/composted manure would go a long way to help your soil building efforts.

Centipede grass is a rhizome spreading grass (just like Bermuda (couch grass)) turning it roots up will help in getting rid of it.

The question is, do you want to go to that trouble here at the beginning or would it be better to utilize those roots to help with soil tilth?
Roots open channels in soil structure which allows more water infiltration and gives bacteria nice places to live, grow and multiply.
When the time comes you can eradicate the centipede by chopping it at ground level (scalping) several times, that will expend all the root energy as it tries to regrow the green parts.

Redhawk

I started a new garden area a month or so ago, on a bare patch of ground, on my heavy clay soil.  I had a bag of random leftover seeds from the last 4 or 5 years.  I didn't know which would still germinate, but I just broadcast all of them over the area, and then walked on them so they would have good contact with the soil.  There were at least 30 or 40 kinds of various garden veggies.  It would be hard for me to believe that this area won't be productive next year.

I'm very grateful for your feedback, guys.  Thank you!

WJ: So, it sounds like I would benefit from broadcasting the cover crop seeds BEFORE mowing down the taller weeds?  Or does it even matter?
John: I'll see if I can get some, thanks.
Redhawk: I'll keep the grass, then.  I was just worried that the roots wouldn't go through the grass once the seeds germinate.
Todd: Awesome picture... I'm inspired!  You also addressed a question I had about walking on the seeds after they've been broadcast.  Didn't know if it was ok to do that.

In a bit, I'll go out and take "before" pictures.  Too hot, right now.  We'll chat soon.

Daly Gutierrez wrote:You also addressed a question I had about walking on the seeds after they've been broadcast.  Didn't know if it was ok to do that.

My experience, out here in the dry desert, is that seeds germinate best when they have been aggressively stomped into the soil. My protocol for planting seeds includes thoroughly stomping the rows at least 3 times immediately after planting the seeds. I suppose the never-compact-the-soil people would be horrified at me... Whatever. The crows aren't pulling my pea seeds out of the ground. I'm getting quick reliable germination.

If you're interested, here are my...
"BEFORE" Pictures

Daly Gutierrez wrote:I'm very grateful for your feedback, guys.  Thank you!

WJ: So, it sounds like I would benefit from broadcasting the cover crop seeds BEFORE mowing down the taller weeds?  Or does it even matter?
John: I'll see if I can get some, thanks.
Redhawk: I'll keep the grass, then.  I was just worried that the roots wouldn't go through the grass once the seeds germinate.
Todd: Awesome picture... I'm inspired!  You also addressed a question I had about walking on the seeds after they've been broadcast.  Didn't know if it was ok to do that.

In a bit, I'll go out and take "before" pictures.  Too hot, right now.  We'll chat soon.

Yes.  Do the thing with the pitchfork to loosen the soil, get some air in it and help it absorb rain water and dew.   Broadcast the seed.  Then chop and drop.  The stuff you chop will provide mulch to cover the seeds and help them grow.  There will be plenty of weed seeds in there too, so you'll have to chop regularly to get ahead of the seeding cycles.  That will give you a lot of mulch and allow the seeds you have sown to establish and begin to crowd out the less desirable plants.  

Joseph Lofthouse wrote:

Daly Gutierrez wrote:You also addressed a question I had about walking on the seeds after they've been broadcast.  Didn't know if it was ok to do that.

My experience, out here in the dry desert, is that seeds germinate best when they have been aggressively stomped into the soil. My protocol for planting seeds includes thoroughly stomping the rows at least 3 times immediately after planting the seeds. I suppose the never-compact-the-soil people would be horrified at me... Whatever. The crows aren't pulling my pea seeds out of the ground. I'm getting quick reliable germination.

Many people confuse compaction with firming up the soil. compaction goes deep similar to creating soil blocks or even adobe bricks, stomping or rolling the soil doesn't create compaction by the definition. I do like you Joseph