Advice on Soil Prep for Orchard

General Fruit Growing
#1

Friends of mine want to plant a small apple, pear orchard (for home use) on silt loam that has grown corn and soybeans for a long time with conventional herbicides. It’s now in winter wheat as cover crop.

They ask: should we do another year of cover crop or green manure crop before planting orchard?

What is most important in a soil test: organic matter, N-P-K or other components?

How necessary is using a sub-soiler to break up hard pan and plow pan under the whole orchard site? Breaking hard pan looks expensive- huge equipment, deep ripper.

I planted my small orchard on poor soil and am paying for it now.

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#2

For my 1/2 acre orchard I took soil samples and mailed to university of TN The form specifies what you want to grow and they sent results back In 2 weeks. Could select basic and expanded testing

I think most states have an Ag extension that runs these. Very inexpensive

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#3

If it will grow corn / soybeans ,likely it is of sufficient fertility for a orchard. I would check the ph. As lime is best incorporated before planting, if needed.
Phosphorus also best if incorporated, but likely sufficient.
Other nutrients can be surface applied later if needed.
May want to check for herbicide residues, maybe a bioassay?
Planting a crop / plant that is susceptible to the known herbicides used to see if their is any damage ?
I just subsoil the tree row , several feet wide,(3-4 ft.) with a small tractor 16 in subsoiler. About 4 passes.
Not too bad, just a small farm tractor 30hp.

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#4

Good advice @Hillbillyhort , exactly what I was looking for.

How important is organic matter? Soils around here are probably 1% OM, probably no worms.

Maybe till under compost over the entire area of the orchard?

Is Atrazine still used on corn crops? I recall that has long residual and can be a big headache for other crops.

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#5

O.M. Is important, but a person can only move so much .
Not up to date on corn/ soy herbicides.
I would want to talk to the farmer, see what they used, when.?
Go from there.

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#6

Here is one link about herbicide residue.
On page 2 it talks a little about bioassay 's
Many ways to do this. ( may put some apple seed ,etc in there ?)
This could be done in a greenhouse before planting time this year ,or in the field this year , plant next year.
Again talk to the farmer to see what you are dealing with.
https://www.ag.ndsu.edu/weeds/weed-control-guides/nd-weed-control-guide-1/wcg-files/15-CO.pdf

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#7

Cover crops are probably the fastest way of adding organic matter short of hauling in compost. A round of a summer cover like clover, summer wheat, or cowpeas followed by winter rye or oats should do a lot. Daikon radish, especially ground hog or cover crop types, will do a pretty decent job of breaking though a compaction layer if sown in fall and allowed to winter kill. You could probably mix it with the rye or oats. Okra is also pretty good at breaking up compaction, but even I don’t need that much okra. After all that, regular mowing of the orchard floor should keep adding to the organic matter %. As for soil test, I think pH and organic matter are most important, but your cooperative extension soil test will probably also include NPK. So long as the organic matter and soil biology are there, and the pH is ok, the NPK sorts itself out reasonably well on most (but not all) soils.

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#8

I say all that, but I would probably rush out and start planting stuff with only some semblance of a plan. Because that’s pretty much what I’m doing in my yard.

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#9

LOL- yes I agree. I’ve never been able to wait a year to plant. This friend is more patient and methodical than I am.

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#10

On a related note: I’m planning on planting/replanting 10 apple trees this spring in a plot that I have amended over the last 3 years. It was used as a garden plot from '16-'18, but last year it lay fallow.

Four are trees that have failed to flourish in poor soil after 4 years in the ground; the other 6 are potted trees that I bench grafted the last couple years.

I had a soil test done last March after all the amending, and the results are these:

pH: 6.3
P: 165 (ppm)
K: 200
Ca: 1785
Mg: 352
CEC: 10
Base Sat: 61%

A lot better than when I did the first soil test three years ago, the pH was 5.0, P=49, K=133, Ca=716, Mg=108, and Base Sat=21%.

BTW, I had the soil tests done by my local UK extension office, it took about 2 weeks for the results, and only cost $3 per sample. In my case I was able to tell them what I was planning on growing there and they tailored the report to show what proper level of nutrients were needed.

From the looks of these latest results, does it look like I’d need to add any more amendments?

The plot has a tendency to accumulate a bit of water in rainy periods, so I’m thinking of maybe plowing in opposite directions of the planned rows, so that I can get some of the soil to mound up. Does that sound like a good idea? I have a double bottom 14" plow to do this task.

The potted trees are on M7 rootstock, and the other four are G210, G890, G222, and G202. Would 15ft spacing between the trees and 13ft between the rows be sufficient?

Also, in moving these four in-ground trees, should I need to keep the root ball with the tree, or shake off the soil from the roots, and plant them as bare roots?

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#11

Did you test for organic matter? Around here that’s the main deficiency. I moved two apple trees a few years ago and made sure to take as large a rootball as three men could slide on a tarp to the new spot.

#12

What you add is definitely based on what you have. The advice to have a soil test done is excellent advice.

My ‘soil’ came back with negligible organic content. (Look up “blue lake sand” to see a bad soil profile) I cover cropped for a few seasons. Some of the buckwheat I planted the first year made it to maybe 6” tall. Not a good means of introducing organic matter. I then got a local tree service to use my orchard as a dump for wood chips. I’ve since been adding 100-200,000 pounds of chips to my orchard for the last two years. One of the applications was about an inch deep over an acre+. It was disced in along with lime. I think there were some issues with N absorption but moisture retention was definitely better. The N issues will be short lived and the water retention will last a long time. Likely just as important, nutrient retention should be retained with all of the biology going on under the surface…anything has to hold nutrients better than coarse sand.

If you’re going to do large scale amendments/incorporation, definitely do it before the trees go in… MUCH easier!

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#13

No, that test isn’t done. The closest test to it is CEC, which basically tells you the consistency of your soil on a 0 to 100 scale. If you are on the low end (like mine at 11), you have a sandy-er soil, close to 100 and it’s more clay-ey.

So, mine is the type that leeches out nutrients quicker, but also doesn’t allow water to pool for too long.

I don’t know how organic matter would be tested. The plot used to be a plot where a horse pasture was. As mentioned, it was really lacking in nutrients before I started amending it. I think over the course of three years, I added about 250lb of lime and about 50lb of 10-20-20, and some triple 10, over a 2000sq ft plot.

These trees have a trunk diameter of an inch or less, would I need to take a huge rootball? I’m thinking about a foot or so wide and deep.

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#14

I’m surprised they don’t include organic matter. It’s pretty standard, and one of the easier things to test. They basically put a sample in a super hot oven and weigh it afterwards to see how much burned off. It’s important to note that the NPK numbers are an instantaneous snapshot, and refer to available (water soluble) NPK. There’s a lot of P and K locked up in most soils, and N tied up in organic matter. Active soil microbes and fungi can unlock the P and K quite well, and once you get above 4% organic matter (and have a healthy soil microbiome [if the organic matter is there and you don’t disturb too much, you will almost certainly get the soil microbiome with time]), the organic matter can provide enough available N for all but the heaviest feeding veggies. Trees and shrubs usually need much less available N. Because of the microbial activity impacting availability, your N results (and to a lesser extent P and K) will often be substantially lower if you take the soil test in the winter than in the late spring/early summer. The pH is also key because it impacts the solubility (availability) of NPK and some micronutrients.

Trees’ roots often spread at least as far as the tree is tall, and fairly deep. I don’t think you need to get all of that, but the more you leave intact, the better.

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#15

Thanks. Other than the lack of OM testing, I think we get some good tests for the price. It can vary from county to county, though. I took some samples to an adjacent county office, and they wanted $7! So, I’m glad it’s cheaper here.

Ok, based on the results I have (pH and nutrient levels), I’d think it’s pretty good soil to plant these trees in?

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#16

Yeah, I wouldn’t worry about the OM too much, I was just surprised. Your price is good, though! Adding more organic matter is seldom a problem, so it’s really more to see if you’re starting at a deficiency. It sounds like your soil is pretty improved over the first test, and certainly headed in the right direction. Even the fact that you’re actively working on soil conditions has probably put your site ahead of the curve.

Also, I should add on the rootball subject: If you can keep the soil on the roots, do it! Shaking the soil off will probably lose a lot of the root hairs, which do most of the work of absorbing water and nutrients, and the tree will have to regrow those and re-establish a soil connection. Dormant bare root trees have the option of regrowing the root hairs before water demand is high.

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#17

Ok, I’ll try to keep the rootball together. Considering how little a couple of these trees has grown in 4 years, my guess is that they don’t have a lot of roots. I suspect their puny growth, other than bad soil, was due to a high water table. I didn’t fertilize them the last couple of years either, but I have other trees the same age or younger than these that weren’t fertilized either and they’re doing much better.

Do you think the spacing is sufficient, that is, 15ft between trees, and 13-15ft between rows?

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#18

I’ll have to let others comment on spacing. Did you keep the trees mulched? Grass and other low vegetation can put up a lot of competition for a tree while it’s trying to get established. The low, wet spot seems like a reasonable explanation, though.

#19

All good advice in here, but I want to plug a great book on the subject, Storey’s Guide to Growing Organic Orchard Fruits. It’s specifically aimed at organic orcharding, but 99% of everything in there applies regardless and they talk about conventional methods as well. Great book.

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#20

$3 is an amazingly cheap test. Where is everyone getting there testing done? is there a cheap place that does a pretty thorough job, Colorado state is $35 and gives ph CEC type of soil with like 9 nutrient profiles but i would love a more in depth or cheaper one.

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