Improving wet, clay soil in newly planted orchard - What plants, fungi, etc to use?

Hi all! I'm new to the permies forum, looking for some perspectives on improving the wet, clay soil in my orchard. Here's the situation.

Goal:
Improve the soil in a newly planted orchard site to give the fruit trees as high odds of success as possible

About the site:
We're in New York State, Upper Delaware area. Zone 5b/6a, good amount of rainfall. Lots of water!
The site used to be a dairy farm maybe 15+ years ago, but for the past 10 years just an open field that got mowed / brush hogged maybe once a year, if that.
The orchard area is ~0.5 acres, on a gentle slope that continues above and below it. Facing West and open to the North and South.
Ground is covered with mix of grass and forbs. Lots of aster & clover.
Planted ~45 new fruit trees in Apr 2020. Various types of apple, pear, plum, persimmon, pawpaw, cherries

Soil & water:
Pretty heavy clay, with a moderate amount of medium-sized (1-3 lbs) rocks.
Seems to be pretty healthy - decent number of earthworms when we were digging the holes to plant the trees.
It gets WET in the early Spring. I believe there is a shallow hardpan, since although it is on a slope, in the wettest time (April), I hit standing water 8" down in most of the site. This varies significantly throughout the site... some spots don't fill with water until over 12" deep.
It can dry out if there hasn't been much rain for a while. I lost a few trees that were in the driest spots of the site during the drought we had in June 2020 (I think no rain for 6 weeks?).

Equipment & constraints:
-I have a compact tractor and a mower
-Willing to spend some money on this, but it's always important to be careful about cost
-The most scarce resource for me is time / labour

Current thoughts:
-Plant lots of deep-rooted cover/companion plants that I could then mow to open up more oxygen/air channels in the soil. I was thinking something like Alfalfa, but I read Alfalfa doesn't like wettish/clay soil.
What plants have attributes like Alfalfa (deep roots, improve soil fertility, easy to mow down), and would work well on this site?
-Encourage mycorrhizae to bring more biomass and capillaries into the soil
What kind of fungi? Where to get them?
-I would rather not bring in lots of topsoil or soil amendments

Thanks for your help!
-Bing

Welcome to Permies, Bing!

One thing I've done, but I'm on West Coast Clay, not east, is to plant Daikon radish. I haven't got the "forage" version with really large roots as I figured they wouldn't have a chance in my clay anyway.

I've also tried to do portable compost bins out of pallets - after a year or so, I can plant in the area through some of the compost - I'm sort of "up-ening' the soil, rather than "deepening" - and then I put my compost bind somewhere else.

There are a few places where I've made the effort to dig down 18" at least (which is hard in our rocky/clay soil) but I've heard 3 feet recommended a fairly small surface area hole and keep adding compost to the hole all summer, along with extra moisture if you get dry summers. The idea is to feed the worms down deep in they hopes they'll help you out. Worms carry and distribute lots of micro-organisms in their poop.

Really, anything that grows well in your climate and that you can chop and drop, will encourage the worms to help you out.

I think the most important thing for improving clay soils is to add as much organic matter as you can. Compost, manure, green manures, cover crops, etc.

Wood chips have been the best thing I've done for my heavy clay soil. The mulch keeps the ground moist and soft in the dry season, soaks up excess water in the wet season (thereby preventing the puddles and the soggy mess we get everywhere else), and breaks down and builds the soil up over time. The wood chips also provide for mycorrhizal fungi, worms, and other helpful things that break down detritus and build soil.

You said you didn't want to bring in a lot of amendments, so mulching the whole 1/2 acre with wood chips might be too much. (I'm doing mine in sections, adding more coverage each year, because I don't have the time or energy to do it all in one go.) But I would suggest maybe mulching with wood chips in those areas where things died because they got too dry during the summer, especially if you intend to replant those areas.

For the rest of it I'd plant a ground cover like clover which can serve as a living mulch (keeping sun off the soil so it doesn't dry out so fast and get compacted), provide nutrients, and add compost when it's mowed.

You can also scatter seeds for things with deep roots that will break up heavy soil and add organic matter deep down. Daikon radishes, cowpeas (if they grow in zone 5/6? - I don't know), mustard (self-seeds like crazy so don't use if you don't want it popping up everywhere), sunflowers (the smaller ones that don't need to be staked), dandelions, chicory, yarrow, comfrey, etc. You might need to lay a light mulch over the seeds so the birds don't help themselves. Let them grow out and go to seed and let the annuals rot in the ground. Stick with perennials & self-seeding annuals to save yourself the effort of replanting them every year.

Awesome, thanks! for the suggestions!

I'm definitely going to try the radishes (though will have to wait for Fall to sow). In the meantime, will try to create some openings in the existing ground cover/sod with a scarifier or something similar, to sow cowpeas, mustard, horseradish, comfrey and prairie dock this Spring.
And also mow a more actively in the main growing season to maximize the vegetative growth from the ground cover that's already there and feed those worms!
I don't have an easy / cost-effective source for wood chips at that scale right now, but will keep in mind.

I like what Laura was saying. Wood chips Wood Chips Wood chips. I have very heavy clay, and I've definitely seen huge improvements in 3 years where I laid down wood chips. The fungi will naturally grow in that environment. Radishes, turnips, comfrey, and even high biomass like oats will all help to grow. Comfrey has done so well in our heavy clay, sending tap root deep. Here in Colorado, its hard for it to grow wild, I would have more hesitation in your area.

Hi Bing,

I know this has already been mentioned, but the best thing I have done for my soil (heavy clay) was to heap on wood chips and inoculate with Wine Cap mushrooms.  The Wine Caps really turn the wood into amazingly fertile garden bedding.  Even if you can only do this for a couple of beds, those beds might well be the most productive on your land.  I am amazed what they did for me.

My two cents,

Eric

Look into getting a roller crimper on the front end of your tractor.  Grow Rye or Buckwheat or what ever has deep roots and can grow in your area.  You can push down the grasses so they act as green manure and of course will out compete the weeds.

If you plant anymore trees, even a small mound helps a lot. In one extreme case, I made an 8” mound about 6’x6’ around a young apple tree that had been there a few years. It got healthier almost immediately. I did have to bury the graft, so it will probably make new roots above the graft.

Bing,

Dennis makes a good point about growing rye, buckwheat, or other cover crop and then terminating before it goes to seed.

Eric

I found alfalfa does really well on my heavy clay. It is alkaline and I suspect that is the reason. Great cover crop, you can mow and mulch or let it got to seed and harvest the seed for sprouts

Natasha - Interesting that alfalfa does well in your clay. Maybe it will be fine in mine too! It's definitely one of the many plants I'm trying out this season, so fingers crossed!

Dennis - Know of any roller crimpers available that are suitable for ~1-2 acres? I went on the Rodale institute website and watched the videos and followed the link to the manufacturer they cited.... all the ones they showed seemed more like for 100+ acre operations!

Eric - I had winecaps pop up in my compost heap last year! Definitely one of the things I'll try is spreading them in the orchard

UPDATE to the plan: Seems that there's a good chance that a shallow hardpan preventing the water from draining deeper might be part of the issue in my area (it's on a slope at moderate elevation, but after the first Spring rains, I hit standing water about 9" down).
Have been reading a bit about keyline plowing and subsoilers; will be trying out a subsoiler this year (in addition to the plants and fungi). Maybe combine subsoiling with putting winecap-inoculated compost into the grooves near the trees.
The trees were mostly 3' high bare roots planted in April last year, so I don't expect their roots to have spread out so much that they would be badly damaged by some subsoiling a few feet from their planting holes.

Bing,
Here is the information from a company in Tennessee.  I am thiinking about the 3 point hitch option and getting a 3 point plate for my Skid Steer Quick Attach Front end loader.  That way I do not run over the grass before crimping it.  

Talk with Greg with Custom Cultipacker.  

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Add sand and compost. I find fruit trees, especially apple trees do not like wet feet.  I lost a whole orchard due to winter run off and clay soil.  Better drainage may be a goid start too.

Hi Trevor! I'm a partial transplant from Brooklyn, too! Narrowsburg is really near us (20 min drive). Would love to connect and hear about your experience being up here the past 3 years!
Will send you an email

Hi Bing and Trevor!

Reading this thread with interest—We are in Livingston Manor and face very similar soil issues, and have tried some of the same approaches—wood chips, hay, cover crops) and hope to start seeing results (good and bad both:-) this year, and hoping even newer beds are ready next fall for baby currants, elders and willows we have in a tiny nursery:-)

Great to see other Sullivan County-area folks here.

Best,

Stokes

Hi, Bing! Other people have said it but I will reiterate - Organic matter is key and you will want wood chips for days. Just thick woodchips across the whole thing - I like to trench them in the first year then just layer the organic matter on top for every year there after.

I live in Ohio in an area where it's thick red clay when you get 6" down - former glacier bed. Same issues. Just gotta load in that organic matter. I get my wood chips free from local tree companies.

Hello Bing,
great that you have planted an orchard. I have understood from Michael Philips, author of The Holistic Orchard that
in order to increase fungus activity in the soil, you just need to put wood chips on the earth around your trees, ramial wood chips they are called.
As far as I understand not oak or chestnut because they have too much tannic acid. I have just planted a bunch of fruit
and nut trees myself and I am going to do that. Michael Philips has a lot of conferences on Youtube. Interesting!
All the best with your trees!
Sat Atma

Sounds like you are already most ng this direction, but I'd recommend subsoiler/chisel plow. On contour if you can swing it. If not, just ripping along between the rows at least once a year to get good channels for air and water and let your microbial allies start to convert that clay into soil.

All the other stuff too, with thoughtful cover and mushroom inoculation

I am on a very old farm. Most of the fruit trees were planted in the sandy upland slope but a plum grove was planted in the clay wetland below. It has done very well but invaded by popular trees which I have harvested for wood. the popular roots continue to invade the field beyond but get mowed a along with the alfalfa that came up from the horse droppings. I cut that section when the alfalfa has set seed but not released it yet and spread it to the less permeable parts of the field. Moles are a big help making drainage tunnels.  There is a natural swale where the water collects on the surface then fallows the mole tunnels out into the hard areas.

Trevor Hipp wrote:I mulched anyways... apparently the wood chips are a perfect home for the Japanese Beatle larva. Aside from collecting them in a soapy water, does anyone have a relatively easy and effective way to control the Japanese beetles???

I live in a different continent, but I also get chafer beetle grubs in manure and rich soil. They are similar to Japanese beetles, I think. When I'm digging and I find them, I toss them out on bare ground, and magpies that are usually hanging around gobble them up. If you have chickens, then I'm sure if you rake and disturb the chips once a year with your chickens alongside, they'd eagerly gobble up all the exposed japanese beetle grubs. If you don't have chickens (or hungry magpies hanging around) I guess you could try raking the chips and tossing the grubs in a container. Wouldn't be feasible on a large area, though.