Help reading my soil test reports

I am not sure how to read this report. Any help appreciated!
What are the issues with the soil and what should I do to fix?

Some relevant info - Last year my plants where showing symptoms of nitrogen, iron and zinc deficiency. I used some home based soil test kits and found PH was high (7.5) , Nitrogen & iron was very low. Here is a list of all the amendments added last year to lawn and fruit trees. I may have gone a little overboard :slight_smile:

Sulphur - Espoma Organic Soil Acidifier
Gypsum
SEA-90 Organic Fertilizer

Azomite Rock Dust
Milorganite Organic Nitrogen
Monterey Dr. Iron Organic Pellets

Dr. Earth 735 Citrus & Fruit Fertilizer
Kellogg Garden Organics Fruit Tree Fertilizer
Jobe’s Organic Granular Bone Meal

Soil Blast
Live Beneficial Nematodes Hb+Sc+Sf

I wonder if the amendments are now messing up these results or rather amendments are working and nitrogen/iron are now high…

Going forward, based on these results, what should I add this year and forward?
I usually apply when flowering begins and stop once its close to harvest (about 2 times a year). All trees were planted in 2016 or later.

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I’m sure others will add their thoughts too, but from the stuff I am familiar with I’d say the following:

Looks like your basic fertilizers are doing fine (NPK) and good organic matter, maybe a bit more K but not much needed. Many of the minor noots are OK to high as well (Mg, S, Zn, Fe, Cu). A little more B and Mn might be good (note too much B is toxic to plants, just like a tablespoon of Borax around each small tree sprinkled around). For the cations, looks like Ca is good, Mg is high (so no more Mg products). CEC of 17.3 means pretty good holding power in the soil (likely clay based, which the high Mg is pointing to also). Your pH is just about perfect too.

If you think the soil sample you sent in was representative (and not just right near the trees where all the amendments were added), then looks like you should be in pretty good shape.

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6.8 ph is a lot better than the 7.5 you had last year. So you are doing good ( the sulfur you put down last year helped )
The 7.5 ph was why you had iron deficiency symptoms (as iron is not readily available at high ph.)

The % saturation colum at the right says 47% so your cup is less than 1/2 full.
The blue box below it (percent cation saturation) shows the individual cations (potassium, magnesium,calcium, sodium) that make up that 47% and the % saturation is how much of them your soil can hold.

On the other multicolored chart with high, medium , low…
It shows you could raise ;
your potassium (the 3rd # on a bag of fert.)
Magnesium ( Epsom salt)
Calcium ( gypsum would be good)
Boron (20 mule teem borax, just a little ,it’s potent !)

Hope this helps

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Steve333, Hillbillyhort - Thank you!

Few things I am still not following -

  • The increasing salinity arrow pointing to the right… What should I do to fix/prevent it?
  • What does this mean? ECe 3.7

Do these tests results provide any help on what is hurting these avocado trees - Save or replace these avocado trees?

Thank you!

That is Electrical conductivity ( I believe ) which is a measure of the ions in you soil." SALT"
<1 is best so your soil is “salty”
The only way to lower it really is to wash it out with" a lot " of water.
I assume water is a very precious commodity there.
So flooding the whole area is likely out of the question .?
May be divide it up like a checker board.
Heavily irrigate the " black squares" ( like you are trying to rinse out a tea bag)
One at a time, as best you can.then do the “red” .
The salt in your water supply needs tested.
Rain water would be best. Does it rain there? Have rain barrels ?
A deep soaking irrigation , one square at a time ,will help leach salt out.
Minimal irrigation will accumulate salt if your water has a high salt content

And yes ,the high ece 3.7 ( with the added salty dog pee) could affect your aguacate

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Thanks!
Its raining now :slight_smile: No rain barrels though.
To wash out with a lot of water - Can I just run the sprinklers, drip, bubble heads, soaker hose etc? How long? Or use a hose to soak manually? I can do whatever is needed… I usually turn the watering off during winter/spring…

Yes your salinity is high. That can damage many plants. Avocado are particularly sensitive. To leach the salt out you need a watering method that wets all the soil surface evenly, doesn’t run off or move about on the surface. Flood works great but isn’t very useful in many situations. Sprinklers are probably your best option. The soil surface should either be grass or mulch. That holds the water where it falls and reduces evaporation. You probably need to apply 12 inches of water to make a real difference. It should be applied at a rate that doesn’t cause runoff.

Drip, bubble heads and soaker hoses are not useful for salinity removal or control because the water doesn’t fall on or leach thru all the soil evenly. They can contribute to the buildup of salinity throughout the yr. The water needs to move down over the entire soil surface. With drip much of the water moves sideways and then back to the surface as the soil dries. The salt does the same and accumulates near the surface.

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Note that potassium is the 3rd letter in the fertilizer numbers (N(itrogen) P(hosphorus) K(Potassium or Kalium in latin IIRC). Your soil has plenty of the second fertilizer number, phosphorus.

The percent cation saturation is useful for balancing the mineral ions (at least the cation ones). The ideal (based upon Albretch’s work) is roughly 70% Ca and 10% or so Mg. Your Mg CEC numbers are way higher so you should avoid any fert or lime which has Mg in it. If you wanted to add Ca, probably gypsum would be the better way to do that, it won’t raise your pH and does not contain Mg. Gypsum also helps break up clay based soils a bit, which I would guess you have from those Mg numbers.

I do have some experience with too much salt in my soil. The soil I brought in for my greenhouse tested very salty (as well as several other issues). It was recommended that I flood with 12" of water which I did before any plants went in. I did that by leaving a hose running in different spots and moving it around every hour or so, but the soil was very level so run off wasn’t an issue. I calculated how long I needed by the flow rate of the hose and how many gallons to get to 12" in that area. Since doing that, salinity has not been a problem in subsequent soil tests; so it does seem work.

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Yes ,3rd # my bad , sorry.

Thanks all!

I’ll target for 12". The Sprinklers should cover 75% of the flat areas. I’ll hose the rest manually. If I see run off / draining issues, I’ll pause until it drains and then restart again. I hope I don’t drown and kill any trees in the process! My neighbors are going to think I am crazy :slight_smile:

Hard decision but decided to pull the avocado out and replace with something else…

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Now I wish I had paid attention during chemistry classes!
Follow up fertilizer question -
Based on recommendations above, here is what I am planning to apply in spring after the 12" flooding. Does this look right? Pls let me know if there are better organic options available…

  • Espoma PO6 Potash
  • Espoma Garden Gypsum Fertilizer (For adding Calcium, reducing salts, breaking down clay)
  • Manganese Sulfate Monohydrate Powder Fertilizer 100% “Greenway Biotech Brand”
  • MILLIARD Borax Powder 1 tbsp per plant
  • A little bit of good quality compost, composted manure, wood chip mulch.

A soil test is only as good as the soil sample. I hope I sampled it right. I did take about 20 samples from all over the garden (fairly small only 6000 sq.ft lot) but now I am wondering if it was deep enough… Will repeat test again next year…

Thanks!

Go easy with the Manganese. I’ve got soils that are nearly toxic from excess Mn. I didn’t apply it. Someone did earlier, ie 20+ yrs ago. Same for the Boron. You also have several other nutrients that are very high. It’s not good to add more of those. Based on what you applied last yr over application could be an issue. Fruit trees don’t need high levels of anything and it can cause issues from toxicity to reduced fruit quality. Given where you’re at even compost could be an issue.

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I would echo fruitnut’s concerns, go easy on any additions; boron and Mn can get to toxic levels very quickly. A Tablespoon of borax per tree is safe (every couple of years), and likely similar amounts of Mn per tree. (For comparison my soil test called for 9oz of MnSO4 per 1000 sq ft, not very much.)

I wasn’t able to find the details about the Espoma products. I would take a close look at what exact chemicals they use. I’d avoid any product that uses chlorine based salts (tends to kill soil life). I would hope their gypsum product is just plain gypsum, which is fine; but it’s not clear why then they call it fertilizer. Locally gypsum is widely available and dirt cheap (like $10 for a 50# bag). No need to get fancy. Same with the borax, I’ve always just used the laundry version of it.

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Thank you both! Got it - Less is good :slight_smile:
Will hold off on any compost application this year. Will calculate qty of amendments needed based on current levels and add half of whats needed. Will measure again next year before adding anything further.

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Thanks! You were right! Looks like Epsoma is Muriate of Potash and has chlorine. I’ll look for Potassium Sulfate 0-0-50

But the only other form of potassium seems to be Potassium Sulfate and I think we don’t want to add any more sulfur :frowning:

Hardwood ashes are a good source of K as well, however they tend to raise the pH. But that might be less harmful than Cl added to the soil. Also, your K levels in the test were at a medium level, unless your trees are fruiting there isn’t all that much need for K beyond that for the immediate future.

If you added sulfur last year, then that may have influenced the S reading in your test. My lab generally recommends 6mos+ from any S application to taking samples. But perhaps not.

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Thank you Steve!

I buy gypsum from Imperial Sprinkler Supply (http://www.imperialsprinklersupply.com), they have many locations, the closest one to you is probably in Santa Clara. Their gypsum is very cheap (about $4.30 for 50 lb bag) and very high quality (not like the junk that Home Depot sells).

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Thanks Stan! Nice Store. The Santa Clara one is not too far. I’ll check with them.