first steps to introduce polyculture to large mowed field

Hello All,

We're located in rural central NY State, zone 5a.  We are preparing to rehabilitate a mowed field of approx. 165' x 165' into five paddock spaces divided by swales on contour.  The field was originally a hop yard, has clay-rich subsoil and is somewhat compacted due too having been driven over with heavy machinery in the past.  The slope averages at about five degrees and faces south-southeast.   In addition to planning fruit and nut trees to be planted along swale burns and dappled in the paddock spaces between swales, we hope to introduce a polyculture of perennial food and soil-improving crops throughout the paddock spaces.

The field has been kept mowed for the past several years and, if left to its own devices, quickly reverts to goldenrod, mugwort, thistle and other competitive ruderal species.  After installing deer fencing, we hope to introduce a variety of ground cover, including white clover, dynamic accumulators such as comfrey, and food crops accessible to both chickens and humans such as sun chokes.

Basically, we are wondering how best to prepare the soil for sewing our desired polycultures.  Is is worth a shallow till if only done once and immediately followed by polyculture plantings?  Would ja year of mulch-application that would block light to grass and goldenrod roots be preferable?  We are hoping very much to avoid the use of plastic ground covering or chemicals, but are also hoping not to need to turn the soil over all at once via tilling.

We are very new to all of this and thank you in advance for your patience with our lack of experience, and for whatever advice or suggestions you might have!

Brian

I have a similar sized 3/4 acre project coming up in the spring, it's also just been mowed for years so it has some well established grass and weeds.    There's going to be a heavy amount of weed seeds banked in the soil, so I'm going to use some no till methods.  A couple layers of cardboard and some heavy wood chip mulch in all of the areas where things are getting planted, and then we'll just continue to mow around them.  Trees will get planted in just by moving the mulch and digging a hole, and for bushes and other perennials I like to drop down some compost or decent topsoil in a mound to make small raised beds. It lets them get established and root through the cardboard.   I'm going to continue to have grass over much of the area for years and just gradually add stuff, but if I was doing a larger planting area, and it sounds like maybe you're planning to replace most of the ground cover and you have that soil compaction, you might do well to do a one time till and then use some large tarps to kill all the weeds that will germinate.  Check out the No-Till Growers youtube channel there's some excellent discussion on establishing market garden beds, terminating cover crops, establishing living mulches / ground cover between the rows https://www.youtube.com/channel/UCLhu5JoRWPgEGDoUFfQHTPQ/videos

I agree with Doug with many options he listed— I personally also like throwing down (ironically) deer food-plot blends as many of the seeds are nitrogen fixers and good to break up soil compaction. I also add dill and winter rye seasonally.

Then I’d also get a bunch of bock-14 comfrey going as it has a deeper rooting system than bock-4 and I don’t want the seeds from the common variety.


And if it is a slow enough going process I would keep adding comfrey by taking root cuttings from the original already-established comfrey until I had more than enough comfrey in the space. This slow process would also allow me to take my time getting the swales in and then slowly plant fruit & nut trees, surrounded by loads of mulch, at my leisure.


Do you have a timeline in mind or can this be a rather slow-going process?

In addition to the good suggestions already mentioned, you can turn the "problem" into the solution. Let the pasture grow for part of the spring and get long. Then chop it and layer some additional organic matter on top. If you've got lots of cardboard or heavy paper, put that down first and follow with wood chips or straw. Plant summer crops directly into the mulch and choose plants that will grow big and shade the plots: corn, pumpkins, sunflowers, anything that puts on a lot of top mass. You could get your sunchokes going in the spot you want them to inhabit. All of these will keep emergent pasture from reclaiming the space. In autumn, chop and drop after harvest and undersow with a winter cover crop like oats.

By the following spring, you should have mostly just your oats to deal with and that's just a matter of chop and drop. Plant into this with your polyculture species and then go into maintenance mode, with cover crops and mulch plantings always at the ready.

It sounds like an ideal spot, and I wish you well with your endeavours - so exciting!
I don't claim to be an expert, but I wish I'd done more soil preparation on my 'tree field' which has compacted silty soil. As others have suggested i'd do a deep 'mole plough to break up the sub soil and improve drainage throughout the field, then maybe cultivate once where I was planting, but leave the rest and just use this as 'chop and drop'. Helen Attlowe has had good success doing this on her market garden/orchard business in Oregon, which was also formerly a compacted horse paddock.
This video extract from Paul's Garden Master course gives a little insight into the orchard area management.

But the more open areas where she does market garden rows she does a similar chop and drop - mowing between the rows and mulching the crops directly with the debris. With an area the size you have, I feel you will be creating a rod for your own back if you try and make it all tidy at once, in fact having some messiness will help with predator habitat. Over time the increase in fertility you create by leaving the plants to grow, will move the succession away from the problem weeds. My understanding now is that the weed roots support the soil biota, so as well as needing mountains of mulch to smother the weeds (which will come back from seed anyhow - nature abhors a vacuum) by just letting them grow and cutting therm back (at the right time of year to minimise reseeding and regrowth) you will build your soil fertility with less overall effort.
Good luck! Please do let us know how you get on.

I'm a convert to the power of roots to do the work. Anything that puts out a lot of growth above ground is also doing a similar thing below the surface.

Here is an example of how I rehabilitated a patch of low-lying ground that was already prone to waterlogging. In June of 2021 it was wet and a dump truck drove across it several times, destroying the grass cover and churning the silt loam into compacted, anaerobic muck. When I stuck a fork into it there was a bluish grey pan just a couple of cm down, a dearth of worms, and it smelled bad (like rotten eggs bad).

Here is how it looked shortly after, as I started layering biochar and stump grindings on top to get the process going:



I hoped to see some emergence from the seed bank once I penned the chickens back up, but even by mid-spring it was still pretty barren. Around the end of December I sowed corn, sunflowers, and amaranth and put another light layer of ramial mulch on top. Here is how it looked in early Feb:



After harvesting the corn and sunflowers in autumn, I pretty much left it alone. Our regional regenerative farming group met at our place in May and we looked at the soil in this patch. The blue-grey layer was gone, and so was the smell. The structure was improving and worms were flourishing in the places we sunk the spade.

The amaranth just kept going, and was still flowering well into winter. Here's early June:



We had an excessively wet winter. And spring. And summer. But in spite of that, even though this is the lowest point on the farm, surface flooding was minor and brief. In past years, this area would see standing water for days on end after winter storms.

One surprise for me so far is that none of the amaranth came back this summer. I thought with that abundant seed crop that I'd at least see a few flushes of seedlings. But the legacy of those root systems will pay dividends for years as long as I don't bring any more dump trucks on the land.

Thank you all for your helpful suggestions!

Phil, I like the idea of staging the process out over two years and chop-&-dropping weeds and cover crops.  In addition to the crops you mentioned such as corn, pumpkins, etc., that provide shade, what other summer crops might work well that might also help break up the soil?  I head daikon does a good job with this, too.  Do daikon produce dense crown covers?  Would comfrey be fast-growing enough to perform this function, too?

Thanks!
Brian

Daikon is brilliant for breaking up hardpans and punching holes in the soil. Turnips and fodder beet (mangel) are really good for this, too. Whether any of these produce a lot of top growth will depend somewhat on the season and how much they need to compete with what's around them. I would beware of planting comfrey unless you are really sure it's in a place where you will want it forever (or at least a lifetime). But it will put out a lot of leaves and they respond well to being repeatedly whacked.

Vetch, red clover, and lotus are legumes that will produce a lot of top growth that can be cut and mulched, and they're all nitrogen fixers that play well in mixed cover crops.

I used this mix in the fall and it did amazing things to the crappy field I planted it in this year. Was actually unbelievable the change in the soil. It had so much roots it was hard to disc up to plant the perennial grasses.

I’m not sure if there’s an equivalent mix for summer though. Most of the cover cropping I hear of is done in the fall.

I didn’t have much luck with the daikons tho as they aren’t near as hardy as the turnips.

Doug, thank you for the no-till channel reference!  Thank you, Chris for bock 14 and deer fodder suggestions...no, we have no strict timeline as yet, just trying to make significant progress each year I whatever directions we can.  Thanks, Nancy, for the Garden Master excerpt.  I am all in favor of letting the weeds continue to perform a useful function until we are ready to fill all available niches with other crops.  Phil, thanks for sharing your experiences with decompaction.

I am now wondering whether or to broad scale mulch application is necessary if I plan to work with chop & drop methods for current weed stands, summer plantings and winter cover crops.  Would these three applications of chop & drop be sufficient by this time next year to sew directly into?  I would probably still spot mulch tree and fruiting shrub seedlings as I acquire them, but would love to avoid the expense and compaction risk of trucking in large volumes of mulch.

Because we don't have a rigid timeline or require financial returns on this project in the near future, I would probably lean toward a no-til approach toward compaction and soil fertility.  I'd also prefer to take my time investigating the best plants to include in the polyculture over time, rather than committing to a total replanting all at once.

fWe have a lumber yard nearby that offers flatbed loads of hardwood bark mulch at affordable prices.  First of all, I was wondering how bark mulch compares with wood chip mulch.  Secondly, I am wondering if the chop & drop method, applied three times a year with weeds, summer crops and winter cover crops would approach a comparably hospitable environment for planting directly into as would bark mulch at applied 2-3 inches' depth over areas to be planted.  I imagine the weed seeds being banked in the soil would still require chop & drop of weed species for several years, anyway.

I very much appreciate your help!
Brian

Doug, thank you for the no-till channel reference!  Thank you, Chris for bock 14 and deer fodder suggestions...no, we have no strict timeline as yet, just trying to make significant progress each year I whatever directions we can.  Thanks, Nancy, for the Garden Master excerpt.  I am all in favor of letting the weeds continue to perform a useful function until we are ready to fill all available niches with other crops.  Phil, thanks for sharing your experiences with decompaction.

I am now wondering whether or to broad scale mulch application is necessary if I plan to work with chop & drop methods for current weed stands, summer plantings and winter cover crops.  Would these three applications of chop & drop be sufficient by this time next year to sew directly into?  I would probably still spot mulch tree and fruiting shrub seedlings as I acquire them, but would love to avoid the expense and compaction risk of trucking in large volumes of mulch.

Because we don't have a rigid timeline or require financial returns on this project in the near future, I would probably lean toward a no-til approach toward compaction and soil fertility.  I'd also prefer to take my time investigating the best plants to include in the polyculture over time, rather than committing to a total replanting all at once.

fWe have a lumber yard nearby that offers flatbed loads of hardwood bark mulch at affordable prices.  First of all, I was wondering how bark mulch compares with wood chip mulch.  Secondly, I am wondering if the chop & drop method, applied three times a year with weeds, summer crops and winter cover crops would approach a comparably hospitable environment for planting directly into as would bark mulch at applied 2-3 inches' depth over areas to be planted.  I imagine the weed seeds being banked in the soil would still require chop & drop of weed species for several years, anyway.

I very much appreciate all of your help!
Brian

Thanks, Joe!
That's certainly an affordable mix.

Brian, there are no rules. A combo of chop/drop and wood chip (or bark, which is also great) mulch would do wonders. The main objectives here are to get more carbon into the soil to feed the microbial community, and encourage a diversity of growth across the surface that won't be problematic when it's time to get your long-term plants established.