[Movingshrub]

I am looking for a sanity check on these recommendations: 90lb of lime and 1lb of potash per 1k.

Concerning the lime: 90lb of lime per 1,000 sqft, limited to 50lb per application, spaced apart by 4-6 months, until I get to 90lb worth applied. Is there any benefit to splitting this into 30lb and spreading it out, or just go ahead and hit it with 50lb now and then 40lb in October? I assume I should use pelletized dolomitic lime du to the Ca/Mg ratio.

Concerning the K20 recommendation - Why would I get a recommendation to apply potassium oxide, which I assume means to apply potash? Is this based on an assumption that I'm bagging clippings? It has been a long time since chemistry class. Will adding potassium free up calcium, and therefore push the pH towards basic? Does the source of K matter, ie sulfate of potash vs muriate of potash? What about doing potassium nitrate?

Concerning all the elements on the soil test - I figured dolomitic lime would push the Ca and Mg. Ammonium sulfate will address the N and S source. It looks like I'm good on P, K(which is why I'm surprised by the recommendation) Mn, Fe (it's possible to have enough?!), and Zn. Lastly, any benefit to applying a multi-pack of micros to push up the Boron, Copper, and Iron?

The Axilo Mix 5 contains:
0.5% Boron
1.5% Copper
4.0% Iron
3.0% Magnesium
4.0% Manganese
0.1% Molybdenum
1.5% Zinc

Loveland's FEature 6-0-0 contains
1% Magnesium
8% Sulfur
10% Iron
2.5% Manganese

It almost looks like some AS, some dolomitic lime, and the axilo mix 5 would address everything.

 

[Suburban Jungle Life]

I like your plan. Keep in mind the AMS may lower the ph anyway so if you put out the 4 lb N with AMS, it may still be a little lower than expected next year but well within range for happy grass! Perhaps another test at the same time next year to see where you are? Lime takes a long time to move through soil but if you want a faster change, you could core aerate before applying. As for SOP vs MOP, MOP has a higher salt index but is about half the price. So, if you don't get a lot of rain or water in the MOP well, it can be detrimental. SOP is preferred but costs more and has a lower % of K. I think their recommendation of 4N:1K is a deficit in the total K use for the year. You will use up some of the K in the soil but not as much as if you skipped K altogether. Maybe they feel it's close to optimum so a small deficit would bring it down a little.

 

[kur1j]

How long does lime usually last?

 

[Movingshrub]

How long does lime usually last?

Are you asking shelf life or how often does it have to be applied?

 

[Ridgerunner]

Other than reducing the level of harsh alkaline soil conditions within a period of time, no advantage to breaking the recommended lime amount into three applications. (follow recommended application rates on the bag of whatever lime product you purchase.) They aren't recommending potassium oxide. In this case K2O is the (arcane) standard for identifying the amount of K in the bag of potassium product. If you look at a fertilizer bag's guaranteed analysis (whether it is SOP, MOP or any other form of K) is would list "soluble potassium (K2O). SOP is 50% K2O equivalent and MOP is 60% K2O equivalent.
Example:



Although there is no known excess level for many nutrients at which they become toxic, I see no reason to find those levels if they exist.. You may want to consider if making continued additions is the better reasoned approach. e.g. Mn, which does have an antagonistic relationship with iron.

 

[Movingshrub]

@Ridgerunner

The message I am hearing from you is - apply the lime, maybe the potassium source, and then stop touching it.

Any idea why potassium is suggested?

 

[Ridgerunner]

@Ridgerunner

The message I am hearing from you is - apply the lime, maybe the potassium source, and then stop touching it.

No mater what, it's going to take about 90#/M of lime to rase your pH to about 6.5 (that's my guess where Wayside is trying to take it.) The usual reason for the 50#/M max at one time in 4-6 months is that amounts greater than that may (probably) create detrimental effects like interfere with the uptake of other nutrients. Mostly micro nutrients and P. This could stress the turf. One visual indicator is chlorosis. Not good for turf health.

Any idea why potassium is suggested?

You haven't read my "simple fertilizing" method .
More and more labs are making recommendations based on maintaining a certain level of nutrients in the soil (what ends up reported on the soil test) then adding a "maintenance amount that would keep (or reach) those levels. Caveat: each lab has their own idea what that soil level should be.
In the ideal world, for every pound of N applied to the lawn, the lawn will use between .5 and 1 lb of potassium,
If no potassium is applied to the lawn, the turf will take it from the soil. Removing 1 lb of K2O (.83 lb of potassium) from the soil will lower ppm by 18. Removing 0.5 lbs of K2O would lower ppm by 9 ppm Adding 1 lb of K2O will raise ppm by 18.
If you apply the recommended 4 lb of N/k, theoretically we can expect the turf to use approximately 36 ppm to 72 ppm of potassium (yes I'm oversimplifying on quantifies). Current potassium levels are 251 ppm. So if you added no K2O this year, we could expect your levels to fall to between 179 and 215 ppm. The recommendation is to add one pound/M of K2O or 18 ppm, so we can assume that Waypoint thinks you should maintain a minimum soil potassium level of about 200ish ppm (179 + 18 = 197 ppm to 215 + 18 = 233 ppm). It's your turf, you pick the target and maintenance quantities to apply for that target.

 

[kur1j]

How long does lime usually last?

Are you asking shelf life or how often does it have to be applied?

Last in the soil. For example after applying lime and you get to 6.5pH and you don't apply anything that would reduce it (e.g. Ammonium Sulfate), would it just continually drop back down to its "baseline" pH?

 

[Movingshrub]

How long does lime usually last?

Are you asking shelf life or how often does it have to be applied?

Last in the soil. For example after applying lime and you get to 6.5pH and you don't apply anything that would reduce it (e.g. Ammonium Sulfate), would it just continually drop back down to its "baseline" pH?

If the dirt was in a sealed container, I wouldn't think it would change. However, both rain water and irrigated water are acting on the soil, plus whatever else we put on on the soil that impacts the pH.

 

[kur1j]

On thst mskrs sense. Im just unsure of how long things last in the soil. I know that my yard had lime applied to it to raise pH. I'm just wondering how soon i'll gave to apply it again.

 

[Movingshrub]

On thst mskrs sense. Im just unsure of how long things last in the soil. I know that my yard had lime applied to it to raise pH. I'm just wondering how soon i'll gave to apply it again.

Just to be clear, my answer is a guess. Someone with a solid answer might chime in otherwise.

 

[Movingshrub]

@Ridgerunner I read through your soil analysis thread. I had a question regarding nitrogen relative to consumption of other elements. I understand there is a ratio in terms of other elements used can be driven by the amount of nitrogen. Is that amount of nitrogen applied or amount of nitrogen consumed? The first we know but the second is a guess. I ask because we know nitrogen sources will volitilize at varying rates depending on the type of fertilizer used.

 

[Ridgerunner]

That's a [email protected] good question and one I have asked since first coming across the consumption ratio 7-8 years ago. That was one of the "turn-offs" for me with the simple or maintenance method of fertilizing. It appears that there is correlation between applied and used. My reading have shown that the 4:1:2 N:K plant use ratio seems to be pretty universally accepted by agronomists. Whether this association has been subjected to strict testing standards I can't say. However, more and more, university turf scientists have picked up and accepted this relationship (that's what re-peaked my interest again), Pace turf has promoted a version (MLSN)and many course supers who have employed this theory (based on the N:K and N) bases have reported being able to hold K values steady from year to year.
Don't get too tied up with the estimated numbers. That was my mistake. I didn't see the forest for the trees. Whether of not the estimated N:K ratio is actually 2:1 or 1:1 or 10:1 and universal for all turfs, really isn't important. Consider them just a in the ballpark starting point. The significance is that there is a relationship between N and the other nutrients. It is going to vary in large due to turf species, local climate and turf maintenance practices. The significant point is that the ratios of turf use for N, P and K should be determinable for an individual lawn by monitoring soil tests. Soil test observation should reveal this usage ratio allowing maintenance fertilizer rates to be reasonably calculated. Once determined, that calculation, in conjunction with sufficient soil sink/bank nutrient values should provide the nutrients needed for optimal growth.

 

[BenC]

On thst mskrs sense. Im just unsure of how long things last in the soil. I know that my yard had lime applied to it to raise pH. I'm just wondering how soon i'll gave to apply it again.

What you're asking will show up in a soil report as pH buffer capacity. Not all labs report it but they can. The higher the buffering capacity the more frequently you'll have to apply your pH amendment. Nutrients just come out of the soil solution at the rate whatever plant uses it at. The google term might be: crop nutrient requirement, or nutrient uptake. International plant nutrition institute (IPNI) keeps ok data set per crop, don't know if they have turf. I think they have an app also

 

[BenC]

One thing about lime: it takes about 750 gallons of water to put 2lbs of lime into solution. If it's mounded up on top of itself and crusts over it might never go into solution. The pro of split apps is that it won't be laying around all year. Always get the finest grade you can to expedite the process.

 

[Greendoc]

I am looking for a sanity check on these recommendations: 90lb of lime and 1lb of potash per 1k.

Concerning the lime: 90lb of lime per 1,000 sqft, limited to 50lb per application, spaced apart by 4-6 months, until I get to 90lb worth applied. Is there any benefit to splitting this into 30lb and spreading it out, or just go ahead and hit it with 50lb now and then 40lb in October? I assume I should use pelletized dolomitic lime du to the Ca/Mg ratio.

Concerning the K20 recommendation - Why would I get a recommendation to apply potassium oxide, which I assume means to apply potash? Is this based on an assumption that I'm bagging clippings? It has been a long time since chemistry class. Will adding potassium free up calcium, and therefore push the pH towards basic? Does the source of K matter, ie sulfate of potash vs muriate of potash? What about doing potassium nitrate?

Concerning all the elements on the soil test - I figured dolomitic lime would push the Ca and Mg. Ammonium sulfate will address the N and S source. It looks like I'm good on P, K(which is why I'm surprised by the recommendation) Mn, Fe (it's possible to have enough?!), and Zn. Lastly, any benefit to applying a multi-pack of micros to push up the Boron, Copper, and Iron?

The Axilo Mix 5 contains:
0.5% Boron
1.5% Copper
4.0% Iron
3.0% Magnesium
4.0% Manganese
0.1% Molybdenum
1.5% Zinc

Loveland's FEature 6-0-0 contains
1% Magnesium
8% Sulfur
10% Iron
2.5% Manganese

It almost looks like some AS, some dolomitic lime, and the axilo mix 5 would address everything.

It is good to split lime applications into smaller ones rather than put it all down at once. Otherwise an extremely alkaline layer will be formed on top of the soil that can interfere with uptake of other nutrients in addition to causing Nitrogen to become volatile.

If I need to apply Nitrogen to a soil that tends to be acid, I stop applying Ammonium Sulfate. My Nitrogen sources become Urea and or Calcium Nitrate. Ammonium Sulfate is what I apply most often because the particular site has soil with a pH over 7. No way would I apply Ammonium Sulfate to a low pH soil unless I was maintaining Centipede grass.

Potassium serves many roles in grass. Potassium affects how well grass resists diseases, drought, and mowing. As @Ridgerunner stated, grass typically uses Potassium in a 4:1:2 ratio. When clippings are collected, one must be extremely aware of how P and K are harvested from the lawn with every mowing. If not lost from collecting clippings, some can be leached by heavy rains or irrigation. The typical Hawaii lawn does not have it good. Clippings are collected every time and the lawn is watered a lot or else it is raining. My preferred Potassium source is either Potassium Sulfate or Potassium Nitrate. Unless the soil is extremely sandy, Potassium Chloride will add salt to the soil that will not go away. When salt builds up. grass will struggle to grow. Due to the soluble nature of Potassium, I like to see it applied regularly rather than a single high dose once a year. After all, this is a lawn we are talking about. Not a forest re plant site where there is only one opportunity to apply anything.

The TLDR version of this is: 25 lb of finely ground Dolomite applied 3 times a year. 1 lb by weight of Urea or 2.5 lb Calcium Nitrate+label rate FEature+label rate Axilo+1/2 lb Potassium Nitrate or Potassium Sulfate applied monthly. The fertilizer amounts are per 1000 sq ft. If you go with the Calcium Nitrate, just know that it is not compatible with any Phosphate or Sulfate based fertilizers. I have mixed it with Potassium Nitrate no problems.

 

[Ridgerunner]

@Movingshrub I was wondering if you have any explanation for your elevated Mn levels (284 ppm)? Is that common for your area (you could contact your local Ag Extension)?

 

[Movingshrub]

@Movingshrub I was wondering if you have any explanation for your elevated Mn levels (284 ppm)? Is that common for your area (you could contact your local Ag Extension)?

I read through this http://www.aces.edu/anr/soillab/forms/documents/ay-324A.pdf
On page 5 -"Manganese is high in almost all Alabama soils and is not recommended for any crop."

I did find this http://www.aces.edu/pubs/docs/A/ANR-0449/ where there is a breakdown of nutrient usage by crop. Yes, I know Bermuda grass isn't on there but I want to use this as an example for discussion. Lets assume all clippings are collected. The category for Bermudagrass hay asserts that 32lb of Sulfur per acre will be consumed. If my soil is showing sulfur at 20ppm (so 40lb per acre?) wouldn't I be apt to run into a shortage of sulfur if the Bermuda grass will consume 32lb per acre? Granted, I have no clue how much Bermuda grass turf will use compared to a hay field.

Also, I went and reviewed my soil tests from the Auburn University soil lab.

These measurements are all in pounds per acre.
6-16-2015 (Front yard) Auburn University Mehlich-1 extract; No amendments had been placed on the yard in 3+ years
pH 6.0
P 136lb/A
K 138lb/A
Mg 373lb/A
Ca 3008lb/A

10-12-2016 (Back yard) Auburn University Mehlich-1 extract; No amendments had been placed on the yard in 3+ years
pH 6.3
P 189lb/A
K 493lb/A
Mg 534lb/A
Ca 4579lb/A

2-6-2018 (Back yard) Auburn University Mehlich-1 extract; Only thing applied between previous test and this test was lots of AS and urea fert, along with all purpose fert.
pH 6.0
P 211lb/A
K 511lb/A
Mg 330lb/A
Ca 2002lb/A

6-15-2018 (Back yard) Waypoint test
pH 5.5
P 242lb/A
K 502lb/A
Mg 292lb/A
Ca 2660lb/A

So are these swings different due to poor sampling? Top dressing with sand? Spreading lots of stump wood chip debris upon the ground which then decomposed prior to sprigging? Applying 13lb of N of Ammonium Sulfate + Urea blend in one growing season (39lb of 33%N product per 1,000 sqft)? Applying 3lb of N-P-K (nitrogen is accounted for in that 13lb) in one growing season?

@ridgerunner
Briefly onto the pH impact of all the fert I applied - if I put down 40lb per 1k of Ammonium Sulfate, with an impact of -110/100lb CCE, wouldn't that have moved the pH about half a point? 6 to 5.5? I also applied 15lb per 1k of all purpose, some 15-15-15, some 10-10-10, some 19-19-19. I'm just trying to make sure I under how to anticipate how my pH is going to be impacted by whatever fert I'm applying this year, and whether I should switch from AS+urea blend to straight urea, or switch to something like Calcium or potassium nitrate?
Furthermore, I'm also trying to confirm that the pH result from waypoint is reflective, ie, does the math add up on what I applied last season taking my pH from 6.0 to 5.5?

 

[Ridgerunner]

I read through this http://www.aces.edu/anr/soillab/forms/d ... y-324A.pdf
Before we proceed, Keep in mind we are throwing hand grenades not darts.
On page 5 -"Manganese is high in almost all Alabama soils and is not recommended for any crop."

The only statement I can make with even some confidence is that Mn has an antagonistic relationship with Mg. Mn can interfere with the plant uptake/use of Mg. Otherwise, articles have stated that there is no known toxic level for Mn, that Mn levels can become toxic at low soil pH levels, that Mn deficiencies are more likely as soil pH levels raise above 6, that Mn sufficiency levels for turf should be greater than 30 ppm (Carrow, et al. sufficiency guidelines https://www.paceturf.org/PTRI/Documents/Soil_tis/0309ref.pdf), to Mn levels below 50 ppm are sufficient and levels above 50 ppm are excessive and tissue levels below 20 ppm are often deficient, levels of 30 to 200 ppm are optimal and levels exceeding 300 ppm are often detrimental/excessive or toxic (Cornell Fact Sheet on Crops http://nmsp.cals.cornell.edu/publications/factsheets/factsheet49.pdf). The take-away: with a Mn level of 284 ppm, you might be well advised to avoid adding any source of Mn in the future.

I did find this http://www.aces.edu/pubs/docs/A/ANR-0449/ where there is a breakdown of nutrient usage by crop. Yes, I know Bermuda grass isn't on there but I want to use this as an example for discussion. Lets assume all clippings are collected. The category for Bermudagrass hay asserts that 32lb of Sulfur per acre will be consumed. If my soil is showing sulfur at 20ppm (so 40lb per acre?) wouldn't I be apt to run into a shortage of sulfur if the Bermuda grass will consume 32lb per acre? Granted, I have no clue how much Bermuda grass turf will use compared to a hay field.

For guidance, see the Carrow site above where recommended sufficiency range levels for sulfur is 15-40 ppm and this for usage rate:



Annual maintenance nutrient (N and K or any sulfate containing ammendment) applications can be used as your sulfur source.

Also, I went and reviewed my soil tests from the Auburn University soil lab.

These measurements are all in pounds per acre.
6-16-2015 (Front yard) Auburn University Mehlich-1 extract; No amendments had been placed on the yard in 3+ years
pH 6.0
P 136lb/A
K 138lb/A
Mg 373lb/A
Ca 3008lb/A

10-12-2016 (Back yard) Auburn University Mehlich-1 extract; No amendments had been placed on the yard in 3+ years
pH 6.3
P 189lb/A
K 493lb/A
Mg 534lb/A
Ca 4579lb/A

2-6-2018 (Back yard) Auburn University Mehlich-1 extract; Only thing applied between previous test and this test was lots of AS and urea fert, along with all purpose fert.
pH 6.0
P 211lb/A
K 511lb/A
Mg 330lb/A
Ca 2002lb/A

6-15-2018 (Back yard) Waypoint test
pH 5.5
P 242lb/A
K 502lb/A
Mg 292lb/A
Ca 2660lb/A

Comparing results from different labs (no matter how good the labs) and especially between tests using different extraction methods, isn't advisable for drawing reliable conclusions. My understanding is that Results from the same lab on the very same soil sample using the same methods can vary by 5% if done the same month using the same extract batches and can vary as much as 10% when preformed 6-12 months later.

So are these swings different due to poor sampling? Top dressing with sand? Spreading lots of stump wood chip debris upon the ground which then decomposed prior to sprigging? Applying 13lb of N of Ammonium Sulfate + Urea blend in one growing season (39lb of 33%N product per 1,000 sqft)? Applying 3lb of N-P-K (nitrogen is accounted for in that 13lb) in one growing season?

Maybe. That and more, including what I tend to classify as "soil dynamics" (rainfall, temperature, irrigation, irrigation pH etc., etc., etc.) That's why it's so important to eliminate as many variables as possible by taking numerous samples, mixing them well,, keeping depth as consistant as possible, taking samples in the same month each year, etc.) (I like using mah exceteras :lol: ).

Briefly onto the pH impact of all the fert I applied - if I put down 40lb per 1k of Ammonium Sulfate, with an impact of -110/100lb CCE, wouldn't that have moved the pH about half a point? 6 to 5.5? I also applied 15lb per 1k of all purpose, some 15-15-15, some 10-10-10, some 19-19-19. I'm just trying to make sure I under how to anticipate how my pH is going to be impacted by whatever fert I'm applying this year, and whether I should switch from AS+urea blend to straight urea, or switch to something like Calcium or potassium nitrate?

Soil pH is the result of the equilibrium between H+ in solution and on Cation sites. Considering that labs and soil scientists can calculate the meq of H+ held on soil exchange sites based on Buffer pH and calculate the resultant soil solution pH, I'm pretty confidant that one could determine the amount of H+ needed down to the atom for pH level and the amount of a substance needed to supply that amount of H+. However, due to "soil dynamics", that ends up just an estimate. For example: the calculation for lime amount needed to neutralize H+ is only accurate to within 500 lbs (some claim 50)/ acre or + or - 10 lbs/M in the field. Neither my knowledge base, skill level nor size of my brain is sufficient to make those calculations.

Furthermore, I'm also trying to confirm that the pH result from waypoint is reflective, ie, does the math add up on what I applied last season taking my pH from 6.0 to 5.5?

I trust no one. I don't know what Buffer pH test Waypoint uses to determine that reported buffer pH. If it were me, I'd call them and ask, and ask them if they could refer you to the LRI index they use to determine the lime recommendation for those Buffer pH results. (LRI charts for all the major tests used to be readily available on the net, but are hard to find these days for some reason).
@Movingshrub I wanted to add that the results from having a buffer pH test can be a double check on the accuracy of the reported soil solution pH, but to use it , you need to know what test was performed and it helps to have the LRI too.

Hope some of that was of help.