# Soil test advice please



## Dmega (Aug 8, 2018)

Got soil tested last fall and need some advice for this years lawn program. I was recommended by the sales man to do the following for the lawn based on the soil test.

_Soils: Phosphorous, Boron, Magnesium, Sulphur and Potash are low
1.	Spring and Fall - Apply 0-0-21 K-Mag, this will help Magnesium and Potash ( water in)
2.	Use Gypsum 2 to 3 times a year to flush Sodium
3.	Use a general fertilizer like 7-2-5 or 5-1-2 or 23-4-10 ( organic based) at least 3 times a year_

I'm not sure if I have been given good advice or not so I will explain. BTW my grass is a miz of cool season grasses KB, PR, Fescue. The way I read the report Phosphorus is at a good level but not really available to be used. Potash is available to the grass, but there's not much. Boron, Magnesium and Sulfur are low but I it's my understanding these micro nutrients are not really necessary to increase as the plant uses so very little of it.

I feel that the uses of my current fertilizer which is organic vegie with an NPK break down of 7-2-5 should be enough to make up the potassium over time going by the recommended nitrogen requirements for grass. I think I can skip the K-Mag fertilizer.

Of the "primary nutrients" Phosphorous is clearly in the soil but not available. The CEC of my soil is on the medium low side (13.5) from my research indicating my soil is on the sandy side? Also the organic matter (2.6)is a bit low too.

Of concern to me is the high amount of salts in the soil (probaly over use of synthetic fert and salting of sidwalks). I'm not sure I really want to use gypsum to flush the soil as that might increase the ph level which is at a good spot right now (7- neutral).

I will continue to use the organic fertilizer which I switched to last year, but I'm thinking of introducing humic acid to the soil to increase CEC and un lock present nutrients. I think it will also increase the soil organic matter and help the root system of the grass to grow deeper and maybe aerate a little bit?

I am curious if humic acid decreases the ph level of the soil and if that would counter any increase in ph that Gypsum will do. I have my eyes on using Andersons Humic DG ... easy to apply, 65% humic and 10% fuvic acid and relatively cheap as one 20KG bag can last my lawn 6-7 years with max recommended application rate.

Look forward to your thoughts, ideas and suggestions.


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## Ridgerunner (May 16, 2017)

Looks like you've done some research. The lab used Olsen and Bray P1 to measure P and it looks like they used ammonium acetate for K, Ca and Mg. Micros were probably DTPA extraction but DTPA and AA are a guess. You can find the recommended sufficiency ranges for those test methods in my soil thread.
A CEC of 13 will hold plenty of nutrients adding OM via HA wont likely result in any visual improvement but it wont hurt anything. CEC is not determinate of whether your soil is sandy or clay. Although, generally, a CEC of 13 would be associate with a loam. 
Not sure what makes you believe P might be unavailable, in fact it appears you have plenty and no indicator that would lead one to believe it is tied up.
mS/cm is millisiemens which converts on a !:1 basis to dS/M. 0.36 is NOT a problem. In any case, Gypsum will neither raise nor lower pH. Gypsum will remove other cations from soil, particularly Sodium, but high salt content , if present, is only reduced by washing it out. https://www.agrilifebookstore.org/v/vspfiles/downloadables/ESC-011.pdf
Otherwise, your thinking is pretty much on track.


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## Dmega (Aug 8, 2018)

Ridgerunner said:


> Not sure what makes you believe P might be unavailable, in fact it appears you have plenty and no indicator that would lead one to believe it is tied up.


Thanks for the feedback @Ridgerunner . The paste extraction indicates "LOW" for phos availability tho there is plenty in the soil. One of the reasons why I wanted to supplement Humic acid was to unlock that potential. Is my understanding of paste incorrect?

I should have mentioned this first but I find I need to water my lawn frequently like every 2 days. I suspect over fertilization is main cause but also shallow roots. Hence why I was thinking of using HA to drive the roots deeper.

I aerate once a year but was hoping by using HA I wouldn't have to. What are your thoughts on this practice?

How does one go about properly and safely watering out salts? Is there a strategy or method which can verify the leeching of salt without expensive test on a regular basis?

Visually my turf looks good but I'm striving for a nice deep dark green colour and its not quite there. There is plenty of iron in the soil so I'm in a bit of a loss. Any sugetions?


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## viva_oldtrafford (Apr 4, 2018)

Yout OM% is fine. In fact, it's under 3, so I'd argue that's where you want it. OM holds more nutrients, sure, but it also holds more water. Water held in the profile for too long, or in quantities too high, can have a negative impact on plant health. Wetter profiles limit the rooting ability of turfgrass - roots need O2, so they will not dive to depths where none is available...and if too wet, they will not survive. OM management is the number 1 reason we aerify greens so frequently.

Flushing salts can only be attained through irrigation flushes with clean water (low ec) / rainfall. Is your EC so high that it's limiting? Turfgrasses vary im salt tolerance; you may be fine.

The Na saturation is pretty high. Gypsum will help you there, but it will also increase your salt load - Ca is divalent and that's how we knock Na off the exchange site, so you're increasing your soil Ca. Again, are salts an issue?


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## Dmega (Aug 8, 2018)

viva_oldtrafford said:


> Yout OM% is fine. In fact, it's under 3, so I'd argue that's where you want it. OM holds more nutrients, sure, but it also holds more water. Water held in the profile for too long, or in quantities too high, can have a negative impact on plant health. Wetter profiles limit the rooting ability of turfgrass - roots need O2, so they will not dive to depths where none is available...and if too wet, they will not survive. OM management is the number 1 reason we aerify greens so frequently.
> 
> Flushing salts can only be attained through irrigation flushes with clean water (low ec) / rainfall. Is your EC so high that it's limiting? Turfgrasses vary im salt tolerance; you may be fine.
> 
> The Na saturation is pretty high. Gypsum will help you there, but it will also increase your salt load - Ca is divalent and that's how we knock Na off the exchange site, so you're increasing your soil Ca. Again, are salts an issue?


So that I understand you @viva_oldtrafford , are you saying humic acid is harmful in my situation because it will increase the OM leading to overly moist soil which will suffocate grass roots?

Flushing soils with clean water or rain is the recommendation to remove salt. To me this means to let nature take its course and do my part by not adding any salt. Does the salt harm my grass? Maybe because I find the colour to be off and I have to water the lawn frequently...I suspect salt is present mostly due to over fertilizing with synthetics. Thus changing that practice will eliminate the main cause and in time rain will leach salt away. When salt percentage comes down in thime watering the lawn once a week would promote deeper roots. Btw Im not sure what EC means...sorry I'm a noob at this.
Thanks for the feedback


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## Ridgerunner (May 16, 2017)

It would appear to me that the lab classified your paste test P levels as "OPTIMAL", not low. Nevertheless, here's an interesting paper on that issue. Please note the 0.25 and 0.28 P levels (albeit for crops, not turf grasses) in the paragraph discussing past P levels. http://cutt.lib.msu.edu/article/2005two6.pdf
The most common reasons for shallow rooting are improper maintenance/cultural practices: frequent shallow watering, and over fertilization. Roots proliferate where they find food and water. Soil texture, physical and chemical conditions like compaction, excessive Mg or Sodium levels can also produce shallow roots. Watering every two days isn't going to help with deeper rooting and using organic fertilizers reduces the control over the timing of nutrient availability.
On the salt issue: you don't have a salt issue. KBG is one of the most sensitive grasses in regards to soil salinity and the dS/m for KBG is 2-3. If you're levels are under 1, that's great and if under 0..5, that's wunderbar. Washing salts out of soil just requires plenty of deep irrigation, keep the water moving down and out of the soil, nothing special. However, all that watering will wash out nutrients too, and saturated soils can create detrimental plant growth conditions. It's always a trade-off.
I'm a proponent of HA. In reasonable application levels I see no downside. When applying granular HA (or many other solid forms of nutrients or soil amendments) I will aerate prior to the application to help incorporate it into soil. I'm not convince that there is any method or product that can reduce soil bulk density other than physical disturbance of the soil (e.g. aeration). Plant roots are by far the best soil aerators. Whatever produces greater deeper rooting will eventually result in better soil.


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## viva_oldtrafford (Apr 4, 2018)

EC = electrical conducy= measurement of your total soluable salts. You may see soil reports that list EC. It's a number to help you guage your salt level, or assessthe salt tolerance of a grass that you may choose to use.

Salts in soil affect the movement of water - osmosis. If the salts are too high, you may have issues, yes. BUT, not all turf types have the same salt tolerance. Some turfs can withstand a large load of salts - so large that it would be hard (impossible) to reach those levels without trying to. PR is the least salt tolerant, but kbg and the fescues have pretty high thresholds.

The use of synthetics can contribute to a higher EC (debate amoung how much impact and with what fert) but the majority of the time it involves the irrigation water.

I think the gypsum will help you quite a bit. I see a lot of soil reports and that saturation percentage is up there. If I'm reading it correct, the count is 77 and very high, and the base saturation in 26% @ ridgderunner - that qualifies as a sodic soil I believe. Sodic soils are different from saline soils and pose their own distinct issue/s. The good thing with sodic soils is that we can cure them with gypsum. The soil sodicity is the only glaring problem here, and it's quite a large one imo (if my reading of this report is correct).


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## viva_oldtrafford (Apr 4, 2018)

Dmega said:


> viva_oldtrafford said:
> 
> 
> > Yout OM% is fine. In fact, it's under 3, so I'd argue that's where you want it. OM holds more nutrients, sure, but it also holds more water. Water held in the profile for too long, or in quantities too high, can have a negative impact on plant health. Wetter profiles limit the rooting ability of turfgrass - roots need O2, so they will not dive to depths where none is available...and if too wet, they will not survive. OM management is the number 1 reason we aerify greens so frequently.
> ...


Choose your own plan for OM, but keep in mind that the addition of OM is going to hold more water - less O2 in the profile and be slower to
drain. you have a CEC of 13, so You have plenty of water and nutrient holding potential in that alone - - your yard could be built usga spec sand and you'd be fine.


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## Ridgerunner (May 16, 2017)

@viva_oldtrafford I'm unfamiliar if a correlation has been established between paste Na levels and soil sodicity, but most sources set a base saturation level (via standard soil testing-NOT paste) of 15% or greater as the threshold for classifying a soil sodic. Anything over 5% can indicate some level of adverse dispersion.
Your comment about the salt tolerance of Rye grass, that it is even more sensitive than KBG got me googling. WTH? Some researchers classify rye as very salt sensitive, others report it as less sensitive than KBG. For example (see chart on page 2) https://extension.colostate.edu/docs/pubs/garden/07227.pdf
I think it is better to be safe than sorry. I'll go with your evaluation (and other classifications of high salt sensitivity for rye). Have you seen any recommended EC thresholds for rye?


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## Dmega (Aug 8, 2018)

Ridgerunner said:


> It would appear to me that the lab classified your paste test P levels as "OPTIMAL", not low.


The phosphorus graph shows "Paste" in Orange meaning low while the "mineral" is green meaning optimal. It was my understanding this means the mineral is present in the soil at the right amounts, but the amount available to the plant less than optimal.


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## Dmega (Aug 8, 2018)

viva_oldtrafford said:


> I think the gypsum will help you quite a bit. I see a lot of soil reports and that saturation percentage is up there. If I'm reading it correct, the count is 77 and very high, and the base saturation in 26% @ ridgderunner - that qualifies as a sodic soil I believe. Sodic soils are different from saline soils and pose their own distinct issue/s. The good thing with sodic soils is that we can cure them with gypsum. The soil sodicity is the only glaring problem here, and it's quite a large one imo (if my reading of this report is correct).


I started reading up on this a bit more...I think you are on to something here and I will probably apply the gypsum tho I don't know how much or what rate.

_Saline Soils: This is soil that contain high total soluble salts that can adversely affect plant health. An important note is that saline soils still have good soil structure intact. Saline soils must have chlorine present (Cl) where sodic soils usually lack chlorine. Soil pH for saline soils is usually between 7 and 8.5. An older name for saline soil is "white alkali" since a white salt film is often present on dry patches of bare ground.

Sodic Soils: Sodic soil have high enough levels of sodium ions to affect soil structure. This means the sodium binds to clay particles so the clay in the soil does not stick together when the soil becomes moist. It often becomes easily waterlogged, not allowing water to drain. When it does dry out, it becomes like concrete and is difficult for plant roots to penetrate. Because the soil does not hold together the soil easily erodes away, especially on hillsides. The plants exhibit drought stress even with what appears to be adequate moisture. The pH is sodic soils are usually between 8.5 and 10.

Sodic/Saline Soils: These soils are a mixture of both, but baline/Sodic soil usually exhibit more of the characteristic of saline soil especially reduced water uptake by plants, leaf burn, etc. On occasion it will cause structural problems in soil. *Treatment of these soils are the same with all three*._

Source-https://www.lawn-care-academy.com/soil-salinity.html

By this description I think my soil is Saline / Sodic becase the pH matches Saline conditions plus there is chlorine in the form of chloride while the high sodium matches Sodic conditions.

I'm also starting to think the high sodium is from the salt applied to the walkway to melt ice around 3 sides of my property.


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## viva_oldtrafford (Apr 4, 2018)

Ridgerunner said:


> @viva_oldtrafford I'm unfamiliar if a correlation has been established between paste Na levels and soil sodicity, but most sources set a base saturation level (via standard soil testing-NOT paste) of 15% or greater as the threshold for classifying a soil sodic. Anything over 5% can indicate some level of adverse dispersion.
> Your comment about the salt tolerance of Rye grass, that it is even more sensitive than KBG got me googling. WTH? Some researchers classify rye as very salt sensitive, others report it as less sensitive than KBG. For example (see chart on page 2) https://extension.colostate.edu/docs/pubs/garden/07227.pdf
> I think it is better to be safe than sorry. I'll go with your evaluation (and other classifications of high salt sensitivity for rye). Have you seen any recommended EC thresholds for rye?


Yeah, sorry. I got the kbg and pr backwards on the write-up. I used the same link that you provided, just wrote it up backwards.

I've just always used the BS and Na levels as a rule of thumb when looking at sodic / saline-sodic soils. The SAR number, if my math is correct, is just under 2, so permeability isn't an issue. I'd still flush with gypsum, however.


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## viva_oldtrafford (Apr 4, 2018)

Dmega said:


> viva_oldtrafford said:
> 
> 
> > I think the gypsum will help you quite a bit. I see a lot of soil reports and that saturation percentage is up there. If I'm reading it correct, the count is 77 and very high, and the base saturation in 26% @ ridgderunner - that qualifies as a sodic soil I believe. Sodic soils are different from saline soils and pose their own distinct issue/s. The good thing with sodic soils is that we can cure them with gypsum. The soil sodicity is the only glaring problem here, and it's quite a large one imo (if my reading of this report is correct).
> ...


Gypsum for sodic soils.

Clean water for saline soils.


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## Dmega (Aug 8, 2018)

@viva_oldtrafford 
My question is, does 10 lbs of pure gypsum per 1000 sq 3 times a year make sense. I read that this is the minimum amount to have an effect on sodium levels. To be frank I'm not really sure how much to apply to the soil. I suppose I would also have to test at the end of the season to see where the levels are at.


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## viva_oldtrafford (Apr 4, 2018)

@Ridgerunner - is this rate too light? That's only 440 lb/ A. I would think that you need quite a bit more. And I'd do it all at once, not at 3 different intervals.


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## Ridgerunner (May 16, 2017)

@viva_oldtrafford On the contrary. my quick search revealed many sources that rated rye as very salt sensitive although I didn't see an EC level associated and a number that say "not so much (stating rye is tolerant up to EC levels of 6dS/M. I think it's wise to treat rye as very salt sensitive.
Regarding applying gypsum, I'm not well versed, but I agree with you that probably 40-50lbs/M would be more in the balpark
@Dmega I don't know what that "graph" purports to indicate. I evaluating on the reported "results." values.


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## Dmega (Aug 8, 2018)

Ridgerunner said:


> Regarding applying gypsum, I'm not well versed, but I agree with you that probably 40-50lbs/Mwould be more in the balpark


Are you saying my situation needs 40-50lbs/M...What is *M*?


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## g-man (Jun 15, 2017)

M is the roman letter for 1000 (eg. MMVII). It is used in the industry as a short version of 1000 sqft or 1ksqft.


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## Ridgerunner (May 16, 2017)

I'm hesitant to go down this path. I don't think your soil is anywhere near being sodic. I don't think your soil has the level of clay content or a high pH or the high BS levels that are most commonly associated with sodic soil issues. I am also concerned that flooding the soil with Ca may create more issues (leaching out other nutrients, changing BS percentages and nutrient ratios) than any gain to be had from reducing Na.

I did some research and finally found some guidance that correlates Sodium and gypsum application:

_"Recovering a foot depth of sodic soil on one acre requires approximately 1.7 tons of pure gypsum (CaSO4-2H2O) for each milliequivalent of exchangeable sodium"_
https://extension.colostate.edu/docs/pubs/crops/00504.pdf
https://s3.wp.wsu.edu/uploads/sites/403/2015/03/gypsum.pdf

Your soil contains approximately 0.3375 meq of Na. Per above guidance, 0.57375 tons of gypsum would be required to remove that amount of Na. That's 26lbs/M of gypsum. (M= one thousand square feet.)
Again, I'm not in favor of this course of action, but the decision is certainly yours to make.


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## Dmega (Aug 8, 2018)

g-man said:


> M is the roman letter for 1000 (eg. MMVII). It is used in the industry as a short version of 1000 sqft or 1ksqft.


Thanks


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## Dmega (Aug 8, 2018)

Ridgerunner said:


> I'm hesitant to go down this path. I don't think your soil is anywhere near being sodic. I don't think your soil has the level of clay content or a high pH or the high BS levels that are most commonly associated with sodic soil issues. I am also concerned that flooding the soil with Ca may create more issues (leaching out other nutrients, changing BS percentages and nutrient ratios) than any gain to be had from reducing Na.
> 
> I did some research and finally found some guidance that correlates Sodium and gypsum application:
> 
> ...


Thanks for the insights...I have some more research to do.


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## Ridgerunner (May 16, 2017)

:thumbup:
On amending the soil and the best products to use or removing Na, I would defer to @viva_oldtrafford or one of the other turf professionals. they have much more hands on experience to draw from than I do.


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## viva_oldtrafford (Apr 4, 2018)

Here's a look at one of my reports - multiple locations within 1 report. Now, most of these are sand based greens (24 years old) but their pH, CEC and OM numbers are very similar. Take note of my Ca counts in relation to my Na counts.

"An ESP of more than 15 percent is sometimes used to classify a soil as sodic. This means that sodium occupies more than 15 percent of the soil's cation exchange capacity (CEC). Be aware that sensitive plants may show injury or poor growth at even lower levels of sodium." colorado state link. Your ESP is 16 and change - not to mention your Ca is half of what it should be. Make the application at the rate that @ ridgerunner supplied


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## desirous (Dec 15, 2017)

@viva_oldtrafford, I am confused. I believe your test report should be compared to his "CHEMICAL EXTRACTION" numbers. His Ca base saturation is 73.9%, and his Na base saturation is 2.5%, nowhere close to 15%. As far as I've read, Na base saturation under 3% is considered OK. What am I missing?


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## viva_oldtrafford (Apr 4, 2018)

desirous said:


> @viva_oldtrafford, I am confused. I believe your test report should be compared to his "CHEMICAL EXTRACTION" numbers. His Ca base saturation is 73.9%, and his Na base saturation is 2.5%, nowhere close to 15%. As far as I've read, Na base saturation under 3% is considered OK. What am I missing?


My base saturation is from a saturated paste test. See his paste extraction numbers.


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## Ridgerunner (May 16, 2017)

@Dmega You've got me down a rabbit hole. Apparently when Na soil solution levels exceed K levels, plants can substitute Na for K, For certain plant functions like turgor, Na can suffice, but for other K plant functions, like enzymes, Na can be a problem resulting in diminished plant growth and repair resulting in cell death.This is in addition to the osmosis issues that Na salts could create create (but your dS/m is under .5). I would direct you to "sodium induced wilt."
I find it interesting that the Na levels are identical via both the chemical and the paste extraction. It might be beneficial to see what the paste levels are now after this wet winter to see how much, if any, washed out. I wonder what your irrigation water levels are for Na and Cl.


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## Dmega (Aug 8, 2018)

Ridgerunner said:


> @Dmega You've got me down a rabbit hole. Apparently when Na soil solution levels exceed K levels, plants can substitute Na for K, For certain plant functions like turgor, Na can suffice, but for other K plant functions, like enzymes, Na can be a problem resulting in diminished plant growth and repair resulting in cell death.This is in addition to the osmosis issues that Na salts could create create (but your dS/m is under .5). I would direct you to "sodium induced wilt."
> I find it interesting that the Na levels are identical via both the chemical and the paste extraction. It might be beneficial to see what the paste levels are now after this wet winter to see how much, if any, washed out. I wonder what your irrigation water levels are for Na and Cl.


Seems like nothing is ever simple for me...yes there is plenty of snow still, but there has been lots of salt put out on the side walks, drive ways I assume this is the main cause.
I suspect my city water I use should be fine regarding Na and Cl but cant be ruled out unless tested.

Monday I'm planning on contacting my local agricultural association regarding this matter. Hopefully they can help shed some light on appropriate steps.

I did contact my Brett young rep for clarification on his proposals.

_Hello Everett. Thank you for the recommendations. You indicated I needed to apply gypsum to my lawn 2 to 3 times a year to flush the sodium. 
1) How much gypsum (pounds to the ground )is required per year or per application?
2)	How many years do I need to do this?

"With your ph and sodium (apply)every year at least for the next couple (years)
5 lbs of product for every 1000 sgft of lawn 
Gypsum cost 12.50 for 18 kg or 44 lbs "_


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## Dmega (Aug 8, 2018)

I just heard back from a Master Gardener in my area. She doesn't think there is anything wrong with my lawn so to leave it alone unless something drastic happens to it. I might still put some gypsum spring time to bring the Sodium into balance and will try to put down some HA some time later.

Thanks for the help @Ridgerunner @viva_oldtrafford

Here's a picture from last October.


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