Yet another soil test from UMass

[GrassWillGrow]

Just recieved my soil test results from UMass this evening. The first column is from 2/08 sample sent to A&L Eastern Labs. Aside from the lime recommendation for the back, what else can/should be done? FYI, I'm moving towards a 75% organic/ 25% synthetic fert program next year. This year I dropped roughly 800 lb grains over 7300 sqft. Thanks for the help in advance

Soil test results 1-Feb-08; 10-7-09 Front; 10-7-09 Back
Phosphorus 42.00; 8.00 ; 3.00
Potassium 207.0 ; 232.00 ; 172.00
Magnesium 145.00; 201.00 ; 132.00
Calcium 750.00 ;931.00 ; 741.00
Sulfur 9.00 ;NA ; NA
Zinc NA ;0.80; 0.40
Manganese NA ;2.80; 6.00
Iron NA ;0.90; 1.70
Copper NA ;0.20; 0.20
Boron NA ;0.20; 0.10
Soduim NA ;NA; NA
pH 6.00 ;6.50; 5.80
Buffer pH NA ;7.20; 6.90
Acidity(H meq/100g) 1.00 ;NA; NA
CEC (meq/100g) 6.50 ;6.70; 6.30
K % 8.20 ;8.60; 6.30
Mg % 18.60 ;23.90; 15.40
Ca % 57.80 ;67.60; 52.50
Na % NA ;NA; NA
H % 15.40 ;NA; NA
Organic matter % 2.20 ;3.70 ; 3.60
Nitrogen (NO3-N ppm) NA ;15.00; 13.00
Chloride (Cl ppm) NA ;NA ; NA
Extractable Aluminum NA ;10; 28

[MorpheusPA]

I'm not sure which P test to believe...before I say anything and insert my foot into my mouth, can you verify those numbers? Or does anybody have any insight on whether the A&L was testing total P and UMass tests available P. as I suspect?

Other than that, Andy will want you to buy some pretty sand.

I'll want you to lime the back. And the iron is way off, so you and Milorganite are going to be excellent friends. Since that'll help raise your OM levels too, so much the better (although they're coming up on their own!)

[GrassWillGrow]

Yeah, that stuck out to me too. I checked a few times before posting, and just re-checked now. The P numbers are what's reported. I'll be dropping the lime this weekend. I was surprised at how low the iron was. I shouldn't be, but I'm surprised how slowly the OM change can take.

[andy10917]

Do you already have the Lime? If not, make sure it's Calcitic, and not Dolomitic. Let me know if you don't know how to get Calcitic. The Ca:Mg ratio needs to go UP.

Do you want to play with the micro's or not?

[GrassWillGrow]

Do you already have the Lime? If not, make sure it's Calcitic, and not Dolomitic. Let me know if you don't know how to get Calcitic. The Ca:Mg ratio needs to go UP.

Do you want to play with the micro's or not?

No, I haven't got the lime yet. Where do I get the Calcitic lime? I haven't looked, but I don't remember that being offered at HD/Lowes or my local feed store. I absolutely want to play with the micros! I'm looking to hit the sweet spot in a few years, so my immediate goal is to get them to better levels. Slow, but consistant progress is fine by me.

[andy10917]

Jonathan Green makes Mir-A-Cal and Mag-I-Cal, and there is a JG dealer in Reistertown, MD called "Glyndon Gardens" about 8 miles from you. They should have it - but call. There are other JG dealers near you - use the Dealer Locator.

Calcitic Lime will "seem" way more expensive, but since you only need 10% as much, its actually cheaper and you don't break your back. And it works WAY faster. The goal is to get the Ca:Mg ratio between 7:1 and 10:1.

[texasweed]

but I'm surprised how slowly the OM change can take.

Most folks are surprized how long it takes. It takes decades to make any significant change.

[GrassWillGrow]

Calcitic Lime will "seem" way more expensive, but since you only need 10% as much, its actually cheaper and you don't break your back. And it works WAY faster. The goal is to get the Ca:Mg ratio between 7:1 and 10:1.

I was just going to ask if I use 10% of what UMass recommended, but then I reread the soil results and they already suggest Calcitic Lime, so I'm back to the original 25 lb/1000. I can't quite read how many lb are in the Mag-I-Cal bags. The website says the available sizes are 5000 & 10000 sqft coverage. Any idea on the weight of each?

[andy10917]

Don't bother with what your soil test said. Put it down at the "heavy rate" that's on the bag. That's the maximum that you should do at once. When putting it down, wear a cheshire-cat grin that says "I'm going to like the new pH this coming Spring".

[MorpheusPA]

OK, I did some research:

"Phosphorus - This test measures phosphorus that is readily available to plants. The optimum level will vary with plant, yield and soil types. 40 to 100 ppm is adequate for most lawn and garden plants. Certain specialty plants may need higher levels" (spelling and spacing errors corrected for clarity by yours truly)

from: http://al-labs-eastern.com/forms/LawnGa ... lained.pdf

So the test is in line with UMass' results, where I'm more familiar with the numbers. Your phosphorus is low. Actually, rather low; 6 PPM and 3 PPM are kind of bad, actually. Since P is used to build DNA and RNA, plus is heavily involved in energy transfer, this is limiting the health of your lawn (and gardens as well, most likely, if you have gardens). For your pH, 20 PPM would be reasonable (on the UMass test).

Since you're in Maryland and still well over a month from winterizing, I'd drop starter fertilizer at the bag rate and then do it again in spring--and do it a week after you lime, if it rains. Wait longer if it doesn't. Phosphorus can bind to calcium.

By the numbers, to raise you to 20 PPM is going to take about 4 pounds of actual phosphorus, so you can expect to add starter a grand total of 4 to 5 times, depending on which one you choose.

I don't care for your sulfur levels, but I'm ignoring those for now. I don't want to push your pH down.

Iron...welcome to the Milorganite Club, since that'll add both organic matter and iron at 4% of the bag weight. You can apply Milorganite any time, any weather, any season, for any reason. Monthly would be good, and you won't have too much trouble with the iron binding up on you with the pH on the acidic side. At first, you'll note the color from the Milorganite's iron doesn't last long, but that will slowly increase.

OM: Milorganite will help, as will any other organic material you can get your hands on. TW's right, significant change can take a while unless you're slamming the soil with organic material. Topdressing with compost would help, but that tends to be a pretty big job. Don't be afraid to apply everything you can get free or cheap, though, to help enhance your organic material levels. This will also raise your CEC from...rather low, actually.

[texasweed]

TW's right, significant change can take a while unless you're slamming the soil with organic material.

Here is my experience with OM over the years. Unless you are talking adding something like 4 to 6 inches and tilling it in like for a garden every year, OM does not change much. When I say significant I mean something like 1 percentage point. So for example if you are at say 3%, it is going to take several years (decade or more)to get to that magic 5 or 6%.

[GrassWillGrow]

Morph - I dropped some Vigoro Super Green prior to reading your post. I have some chlorosis, knowing I'm low on Fe, I went with that.

What ranges are you and Andy looking for in P & K? I'm reading a book by Nick Christians, in which he indicates most university recommendations on soil samples generally overestimate the amount of P and underestimate the amount of K needed for turf. For P, he uses the following: 0-5 ppm - very low; 6-10 ppm - low; 10-20 ppm - adequate; 20+ ppm - high. For K, he uses the following: 0-40 ppm - very low; 41-175 ppm - low; 175-250 ppm - adequate; 250+ ppm - high.

[andy10917]

For Potassium, I personally believe that the Optimal Zone is 191 - 300. Phosphorus is more complex because different tests are used. The Bray Test is used for soils that have a pH of 7.1 or higher. Values of 26 - 40 are Optimal. The Olsen Test is used at pH lower than 7.1, and has an Optimal Zone of 16 - 24. So, for your soil, 16 to 24 is right.

[MorpheusPA]

Roughly, I'm using the same standard Andy is. If P were 15, I'd be a little edgy, but not much. 20 and I'm fine with it. 25 and I'll tell you to retest next year and not add any. For you anyway, with soil well under the borderline for phosphorus issues. For me, 25 is what I'm considering the minimum with a pH of 7.2 and 30 would make me happier.

For K, I personally prefer the 250 to 300 range. It's not considered a pollutant, it binds to soil pretty well, and it's cheap besides.

Vigoro Super Green is fine if that's what you want to use. I use it myself as my Winterizer step since organics aren't effective here in November.

[GrassWillGrow]

Since P doesn't move well in the soil, and therefore shouldn't be a problem environmentally in my case, I'm planning on dropping a starter as my winterizer app. I'll probably use some cracked corn in the spring (I don't like to hit it with much N until late May), then drop some starter to help with the P.

So assuming my Mag-I-Cal fixes my pH issue in the back (I'm sure it will) and we already have a plan for the P, I'd say my next issue to fix is the Fe. Everyone agree with that one?

[MorpheusPA]

P isn't mobile, but can erode away. Particularly if it's on thin grass that sees a heavy rainfall while the ground is still partially frozen. I usually don't recommend heavy P fertilization within at least a month of ground freeze.

It sounds like Fe is up, and it's not like you can't work on two things at once. You. Milorganite. Good friends.

[andy10917]

Not trying to start an argument, but I don't like to raise false expectations. P and K are quite immobile in a Loam or Clay soil. With so many less exchange sites, Sand is a different story. To stick with our ongoing China Syndrome analogy, neither P nor K ever ride the Express Bullet Train to China, but there are aren't many train platforms in GWG's 6.5 CEC soil either. Choo-choo!!!! Next stop, Beijing!!!

[MorpheusPA]

Ah, no argument, I forgot about that. Yeah, with the Orient Express going on there, I absolutely, positively wouldn't risk putting P down as winterizer, nor would I bother smashing it until I had the CEC up using organics.

[GrassWillGrow]

No worries. I can wait till spring and next fall to drop the starter. And the Milorganite will slowly help the P issue as well. 4 lb actual P to get me to 20 ppm. If my math's right, each bag of Milorganite will give me 0.04 lb actual P/1000. Good thing starter is available (0.87 lb actual P/1000/bag). Of course with the starter, I also get 1.48 lb N/1000/bag @ 18% slow release. Might focus the starter in the fall and use the Milorganite until then.

Any idea on how many lb of Fe I need to get to optimal?

Is there a book out there that helps with these calcs? I never would have known I needed 4 lb actual P to raise my levels to 20 ppm.

[MorpheusPA]

That's actually a rough guess--based on an article about Minnesota soil.

Very roughly, 100 pounds of iron per acre (2.3 pounds per thousand) will raise soil levels by 10.5 ppm. Very roughly. I repeat: very roughly. A high/low pH will alter the actual numbers, as will excessive P, and half a dozen other things.

http://woodleaffarm.wordpress.com/about/

This link has some bits about how much of what to add, but I'd definitely not consider that completely accurate, especially when dealing with the micro-elements.