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On top of Brush Mountain, Pa.

Does anyone have any information on what the toxic levels are for Ca, Mg, K and phosphate? From what I have been able to find relative to levels in parts per million there are no toxic levels for phosphate though 100 PPM is considered adequate, a potassium level over 800 PPM may be toxic (some say 350 PPM), Magnesium levels over 300 may be toxic and a calcium level greater than 2500 is considered to be high. We are all adding various things to our soil and getting soil tests but when is enough enough or too much. As an example, my phosphate level in pounds per acre is 3646 and in parts per million 796. Is this too high. Is it toxic?
My calcium is at 15,244 pounds per acre and 5480 parts per million (thank you gypsum. Many other growers have similar levels and are growing big pumpkins. When is enough enough and when is it too much. Any thoughts on when to stop?

10/24/2004 11:47:18 AM

Ctpumpkin@optonline.net

Hey Marv,

It's hard to imagine any but Phosphorus getting to toxic levels.

Even at 800PPM, Potassium isn't really "toxic" since it's a trasient nutrient that plants don't luxury feed or absorb in surplus. But the sources we apply can lead to Cl or S04 toxicity from surplus chloride or sulphate levels in the soil solute.

I've now tested some amazing soils. One "Hitter" I tested was over 800PPM of K. But like you, the Calcium was so high things stayed in balance. The PhD at my lab was flabergasted when I consulted him on this test. When I first started sharing data & consulting him he used phrases like "soil torture". Today I have him convinced & he has rethought his position away from normal agronomics & sustainable agriculture & is now sitting in the court of competition grade soil management practices.

This hasn't been easy for either of us. I always recommend corrections to "the minumums first" then "the ratios". But today I have reset the thresholds in my soil test tracking software to reflect new minimums that are higher than my old maximums.

Our most likely source of trouble comes from knocking availability of certain non-deficient elements out availability with suplus levels of others. The most likely issues are the Ca:K02:Mg ratios. But micronutrient problems with Iron & Manganese are frequently seen around here. Thus I promote the use of a special Sulfate of Potash that has both Iron & Manganese Sucrate blended with it in one bag to offset this local problem. My emplyer developed it for sand based pitting greens, but if fits our local pumpkin conditions like a hand in glove.

I'm a firm believer in good soil Calcium. But 15,000 lbs per acre is WAY beyond the levels that any Atlantic Giant can really use in a growing season. LOL

You can safely ease off on the Gypsum for a while. :o)

I'll see if I can find the real threshold data for Magnesium tomorrow.

10/25/2004 11:46:04 PM

On top of Brush Mountain, Pa.

Thank you for the reply. I anxiously await the rest of your response. For awhile I thought I might not get an answer from anyone. I have asked some of the most successful giant pumpkin growers I know what the toxic levels are for Mg, Ca, P and K but I never really got an answer that made me feel comfortable. Most everyone will tell you what they are doing and about balancing your Ca-Mg-K according to the Albrecht Formula, about the various ratios based on pounds per acre or parts per million of nutrients but not when you have gone too far and should just sit. Even the organic growers will say add rock phosphate, greensand and compost or manure to maintain your garden and gypsum to "soften" your soil and remove excess water soluble fertilizers and salts but never will say exactly when you might have stepped over or are getting close to the line. Most growers seem to be focused on soil deficiencies and balancing their soil but not on toxic levels of nutrients. I would like to know for certain that I am not killing my plants with "kindness."

10/26/2004 8:51:13 AM

Ctpumpkin@optonline.net

Magnesium toxicity appears to also be a myth. Most often incorrectly diagnosed as a Calcium deficiency due simply to the occupation of available soil cations. Se we're back to the balances.

Besides a paid subsriber site, this was the best resource I could find online:

http://www.rngr.net/Publications/fnn/Summer%201996

10/26/2004 10:17:22 AM

On top of Brush Mountain, Pa.

I went to the site you mentioned and read the article about magnesium. Although it was interesting it didn't mention what levels in a soil test might be concerning. Also, in your discussion about calcium levels you did not give me an answer as to what the toxic levels are. I sort of feel like I am right where I started. No numbers for Ca, Mg, K or P as to txicity. Are you saying that there are no toxic levels for Ca and Mg? And that you have no numbers for K or P?

10/26/2004 2:24:21 PM

On top of Brush Mountain, Pa.

Hey Tremor. I thought you were going to enlighten me on the toxic levels. I am disappointed. It looked like you were having a strong start but then you seemed to lose interest. Are you holding out on me or is there no answer to my question? Come on, I really need you help.

10/27/2004 5:34:22 PM

Ctpumpkin@optonline.net

I've polled some fairly talented people who all hold the same opinion. There are no known values with respect to modern agriculture practices. Truly tortured soils can be found. But more often than not, the conditions are changed with the re-balancing of the other elements or drafting down with alternate crops.

Bottom line: If salt indeces are respected, then almost no nutrient surplus can't be balanced back into production.

10/27/2004 7:08:41 PM

On top of Brush Mountain, Pa.

So you are saying that the toxic levels are unknown for Ca, K, Mg and P or that there are no toxic levels? You hinted that high phosphate might be a problem. By salt indices that we are to respect are you talking about the Albrecht Formula or something else like sodium. There is more literature out there, I believe, that says the Albrecht Formula is a bunch of hooey than there is supporting it. Do you think the Albrecht Formula is helpful or do you just believe that having adequate amounts of nutrients is the important factor. Also what does your last statement, "If salt indeces are respected, then almost no nutrient surplus can't be balanced back into production" mean? I just don't get it. You need to make it clearer to me as chemistry is not my bright spot. And should the word can't have been can? Please do make it clearer. I want to understand this concept so that I can use it. Also are you saying that once there is a surplus of some nutrient in the soil that nothing can be done? Also what is a "tortured soil." Does that mean one that is out of balance or has one nutrient that is particularly high? My soil right now has a CEC of 19.4 with saturations of K 4.6%, Mg 18.2% and Ca 77.2%. Is this good enough? I know the magnesium is a bit high but I guess not toxic. Just give me a little more help. I am close.

10/27/2004 7:50:19 PM

Eugene, OR

If Steve doesn't mind me jumping in here, I believe he's saying that as long as the salt levels in your soil are at an acceptable level, the Ca, Mg, P, and K levels can always be put back into balance to allow uptake regardless of their levels. In other words, as long as the ratios are correct to allow proper uptake we don't have to worry about a "surplus." Is that right Steve?

I started out with an Mg saturation of 33.3% this Spring and the plants and pumpkins seemed to do just fine. My potassium level was above 2200 ppm while the Mg level was over 1600 ppm. Not even close to the proper Ca ratios but definitely not toxic either. I bet other growers out there have much higher levels than I. Andy Wolf could help in that area.

10/27/2004 8:00:01 PM

berkshire M.A.

What is the rest of your soil test look like .How's the pH .By adding gypsum i assume that in is in the range . These are some things i would do for my soil . I would try to get the cec higher ,work on natural organic N,P,K and Ca .i would try to lay off on the Mg in the soil prep and feed as much as i could .Everything works together .My second year my salt levels were somewhat high (the more on fertilizer feed ).Ya it works but later down the road it will catch up with you..Steve is a very helpful Grower he knows what he is talking about.

10/27/2004 8:32:28 PM

On top of Brush Mountain, Pa.

Brian:
Thanks for your response to my question. I'd still like to hear from Tremor. But, Brian, when you say salt level are you talking about sodium chloride or sodium or what. There are a lot of things that are considered salts. Also, from what you are saying about your soil and the success you had may just be another indicator tha the Albrecht Formula does not apply to pumpkins. What do you think? The Albrecht Formula is not written in stone and there are people who think it doesn't hold true.

10/27/2004 8:34:16 PM

Eugene, OR

I'm only just starting to learn the basics of soil, balancing, and what's considered ideal for AG's(Thanks to Steve) so he would be the guy to talk to for sure. Regarding your question, I believe we're most concerned with the soluble salts.

From what other growers have told me, I do believe the Albrecht Formula could be considered close to "ideal" for pumpkin growth. According to the formula, the Ca:Mg ratio is around 7:1 and the Mg:K ratio is around 2:1. Don Langevin considers these levels to be pretty darn close to what we're after for optimum calcium and potassium uptake. However, these plants are pretty amazing and can probably tolerate various conditions and do pretty well.

For all I know, the Ca:Mg ratio being so far off could have resulted in poor uptake directly from the soil. To be sure there was enough available calcium and potassium after pollination, I used a liquid calcium chelate as well as Neptune's Fish+Seaweed and a liquid kelp product. Could this have helped the plant by making up for the imbalance?? I have no clue....but I bet it didn't hurt.

Steve and other more experienced growers would be able to help you more. I'm just a rookie trying to get a handle on all this soil stuff. Good stuff to think about though.

10/28/2004 1:53:39 AM

On top of Brush Mountain, Pa.

Actually I am waiting to see what Tremor has to say. He must be busy as we speak working in his patch. Last night I went to the Atlantic Giant Genetics Site and reviewed the soil tests of many of the successful growers. It was of interest to note that some of them had very high levels of nutrients and many had soils that did not come near the range of the Albrecht Formula for "balanced soil." Yet they are growing huge pumpkins. Nic Welth reported an organic matter level of 25.6% in one garden (WOW). Quinn Werner also had a Ca level of 7558 PPM in one test while Zunnino in California had a Mg level of 956 PPM in another patch. Nic Welty also reported a Mg level of 840 PPM and K level of 1271 PPM. These are very high values but apparently not toxic as these individuals are growing the big ones.

10/28/2004 9:13:33 AM

Ctpumpkin@optonline.net

No Marv, just busy bringing home the bacon. See the related post at:

http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=20&p=93721

I always recommend amendments (or chemical fertilizers) to the "minimum standards" first. The ratios are less important as previously stated.

The Cation nutrients don't really "burn" or become toxic when they're held in the soil solution. But as indicated by the now 50 year old Albrecht Formula, the cation nutrients can interfere with one another. At extremes, surplus induced deficiencies are a reality. Usually short term.

That said, the ratios are no where near as critical as Mr. Albrecht once had us thinking. The early New Jersey forage crop data yielded some hard dying myths that haunt us to this day.

Albrecht felt a 10% Hydrogen level (which yields a pH of 6.0) was the ideal. Do we still subscribe to this theory?

No.

So what part of Albrect shall we pick & choose as our gospel?

I have evidence that Andy Wolfe has collected as well as my own, that 1000+ lb fruit have been grown on soils whose cation nutrient ratios have varied from 3:1 all the way up to 9:1.

My reasonable range then is 4.5 - 7:1. This shouldn't be considered carved-in-stone gospel. It's just a fair target.

It's a good thing Mr. Albrecht never grew AG's.

That's all I have time for now. More later.

10/28/2004 9:34:03 AM

Ohio

Just out of interest, since you guys are giving so much advise, what are your personal bests? The proof needs to be in the pudding. Or, at least it should be. Tremor, how many have you grown that weighed over 1000 pounds? How about you Lubadub? You have been mostly asking questions but I wonder have you had any real success? Myself, I know very little and am just beginning to get into it. But I would like to know if my coaches have ever really been in the game.

10/30/2004 9:36:54 PM

Ontario, Canada.

Willie, what kind of question is that? Just out of interest why don't you watch and read some more before you post. Do the Research yourself. Many growers on this forum have not attained these levels yet due to many factors. Your question is confrontational. Watch and learn. Start here and then move onto the books if you can't trust the informaton you receive here. We have lost many Heavy Hitters here at BP.com due activity like your last post. Steve has been around for a long time and willing gives out spot on advice and he is tremendously well respected.

10/31/2004 8:15:24 AM

Appalachian Mtns.

Do you have any idea how hard it is to grow a 1000+?
Alot of folks think it's not that hard...inexperince and ignorance breed that attitude.
There's been guys growing 10+ years and still haven't grown that size. They know more about soil and pumpkins than you'll ever know.
Think before you ask.

10/31/2004 10:46:00 AM

Ctpumpkin@optonline.net

How do Willie? That's some greeting. Are all Columbus growers so cordial?

You're right. This rocket scientist hasn't walked on the moon yet so we'd better forget all those years wasted in school! LOL Disregard everything I've said.

281.6 is the best we've put on a scale these past 2 years. The ones I've blown up weigh more than my truck but they don't count.

Marv's been kicking my butt since 1996 so maybe his opinion counts. We'll let him spill his own guts if he feels obliged to do that.

10/31/2004 10:52:27 AM

Ctpumpkin@optonline.net

Yikes! According to AGGC Howard Dill's PB is only 980! There goes the sport!

10/31/2004 12:07:54 PM

Hobbiton New Zealand

I am always amazed at about the same time every year a name I have not seen takes a shot at someone on here who is nothing but helpful and is more than willing to answer any fert/soil based question no matter how big or small the question is. Cant wait for later on when it starts to real real angry in here!

10/31/2004 2:06:25 PM

Long Island,New York

Geez...That George Lloyd must be terrible too.....willie-do you know matfox???..............

10/31/2004 2:09:51 PM

Ohio

WIld Willie rides again. I guess pumpkin growers are like fat girls. Weight is something that cannot be discussed. Okay, sorry I asked. But, I don't think asking who has grown what is so confrontational. You guys are very sensitive. Tremor has not grown one over 300 pounds? Yet, he is an expert? I guess so. But there are answers and there are answers. Who knows what is correct? In pumpkin growing isn't size the only thing that counts? Did the Emperor have no clothes. Back to Lubadub's question (and pumpkin growing rather than bashing),there are no known toxic levels fo P, K, Mg or Calcium. There have to be toxic levels as you could not grow anything in pure P, K, Mg or Ca but the levels we are going to attain in our gardens are most likely not going to be toxic. Balanced nutrients are important but the Albrecht formula is not written in stone. If I offended anyone I apologize. P.S. Lubadub, have you grown one over 1000?

10/31/2004 7:13:09 PM

Appalachian Mtns.

My soil test results go way over what most of you would call toxic...my best is 620, and that was 1st years beginners luck. My plants are'nt freaking out, and grow just fine and normal so I don't believe in levels that are "toxic". My problem is my skill level...it ain't there yet.

10/31/2004 7:31:29 PM

Eugene, OR

Willie, By your reasoning we shouldn't confer with the majority of soil scientists working at labs across the country because they don't grow AG's and have probably never grown a 1000 pounder? Soil science is just that....a science. Steve is a professional working in the agriculture field and he's shown time and time again that he knows his stuff. Regardless of personal bests, every last grower here deserves your respect. However, you've just proven beyond a doubt that you're the exception to that rule.

11/1/2004 1:52:40 PM

On top of Brush Mountain, Pa.

Okay. I'm back. I asked about nutrient toxicity and it looks like the postings got toxic. Anyway, Willie is saying that we don't have to be too concerned about reaching toxic levels in our gardens and that the Albrecht formula is nice but only a guideline. Does everyone agree with this?

11/1/2004 6:41:49 PM

Appalachian Mtns.

Yes

11/1/2004 6:46:43 PM

Utah

wiLLie - according to your own rule - none of us should listen to anything that you say ... because you are a self admitted new grower who hasn't grown anything, is that correct ?
I've been growing off and on for 8 years but I've never reached 1,000 lb. Does that mean I don't know anything? Does that mean I've never learned anything in all those years?

11/2/2004 9:04:28 AM

Covington, WA

Hey Willie, to use a sports analogy, some of the best coaches and managers in baseball and football were mediocre players in their careers. But they understood the game whether they had all the physical tools to play it or not. Pumpkin growing is a lot like that. You don't need to be a consistant heavy hitter to know how to do this well, and this isn't baking where you throw the ingredients together and put it in the oven at 375 for an hour and it all comes out perfect. You can learn a lot here from growers with lots of experience and not much to show for it as well as those who learned all they could and put it to use in a very short time. If your looking for a personal mentor check the attitude when you log on. This is the off season and things can get ugly fast.
And my best answer for Marv is balance in the nutrient levels whatever the numbers are. My understanding is the higher they are, the harder it is to maintain that balance without locking nutrients up or blocking nutrients. Calcium can interfere with Potassium and vice versa, both are needed in varying degrees at different stages. Phosphorus can get bound up and not be available despite what the numbers are supposed to be. Tissue analysis is the only real measure of what is making it into the plant.

11/3/2004 2:40:23 AM