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  #21  
Old 07-25-2009, 03:18 PM
Kiril Kiril is offline
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Originally Posted by muddstopper View Post
Saturation levels cannot exceed 100%.
A solution can become supersaturated with an ion (i.e. > 100% or SI > 0) if the conditions are right.

I started to write a long reply explaining why this is not as simple as you are trying to make it, and some of it is just wrong, but instead I will just point you to the docs I have previously referenced.

http://lawr.ucdavis.edu/classes/ssc102/

Pay particular attention to sections 3, 6-8.

With respect to P, please check up on solubility constants of different P species/compounds and how that may or may not affect availability at low pH. Once again, these micro/macro nutrient problems with respect to high soil P are mostly associated with high pH soils, not low, as is the case here.


Quote:
Originally Posted by muddstopper View Post
As you said, soil fertility is more than CEC. All soils start out from rock and nutrient levels are derived from the parent material. You have rock,then gravel, sand, silt, clay and then humis. Since humis resist decay, it also has the strongest ability to hold onto nutrients. It also will have the greatest diversity of nutrients. A tomato plant planted in a clay soil will outperform a tomato plant planted in pure humis, while a tomatoe planted in a mixture of clay and humis will outperform either. Soils with high humis levels, (over 7%), are generally nomore productive than soils with low humis levels, (2%) when the same amount of imputs are applied. I doubt that there is any soild rule of thumb on exactly how much humis is to much because of the various soil types
SOC (soil organic carbon) is not comprised of strictly humus (humic compounds). Also, you cannot compare a "soil" comprised strictly of humus to one that is a mix of humus and mineral components. Where are you getting this information?

Also your same inputs and productivity example does not pan out. Why would you apply the same inputs on a soil with a higher CEC (i.e. nutrient retention) as a soil with low CEC?

I think the more important relationship to draw is fewer inputs are required to get the same level of productivity in soils with higher CEC/SOM strictly due to better nutrient retention, soil structure, etc.... If anything, I would expect a decline in productivity in a strictly humus soil if fertilized at the same rate as, say a sandy soil, due to the potential for nutrient toxicity over time.

@Bill

Just because no "visible" improvement is noted does not mean there is not an improvement. More likely that not, a "visible" improvement was not noted because there were no limiting nutrients (i.e. luxury consumption was the case) or limiting conditions, not because the SOM was at 9%.

While we are at it, please define "enough available OM". Available for what?
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  #22  
Old 07-25-2009, 06:12 PM
growingdeeprootsorganicly growingdeeprootsorganicly is offline
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soil test... sul-po-mag + lime plus lots of post, that guys area receives lots of rain each year so to me mineral augmenting would be wise

a soil with high P and low pH one would think not have a micro nute issue simply because of the soil's pH. no?

pure clay soil vs humus soil...? mudd, i respectfully disagree again

bills little story? bill what are you telling people???
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  #23  
Old 07-26-2009, 01:04 PM
ICT Bill ICT Bill is offline
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Quote:
Originally Posted by Kiril View Post
@Bill

Just because no "visible" improvement is noted does not mean there is not an improvement. More likely that not, a "visible" improvement was not noted because there were no limiting nutrients (i.e. luxury consumption was the case) or limiting conditions, not because the SOM was at 9%.

While we are at it, please define "enough available OM". Available for what?
I agree with you completely, what I was trying to point out was the point of view of the customer and how simple and flat the thought process was, I should probably move this to another thread.

Although these are some very bright folks with degrees and obviously smart business folks it still came down to one thing "I didn't SEE any improvement" and was told that compost obviously does not have the affects that I told them it did.

The customer still had the fertilizer mentality, apply something at 8AM and by 4PM its green. directly feeding the plant rather than growing soil fertility

No I did not go into a porosity, CEC, cation debate with them
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  #24  
Old 07-26-2009, 03:29 PM
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muddstopper muddstopper is offline
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Quote:
Originally Posted by Kiril View Post
A solution can become supersaturated with an ion (i.e. > 100% or SI > 0) if the conditions are right.

I started to write a long reply explaining why this is not as simple as you are trying to make it, and some of it is just wrong, but instead I will just point you to the docs I have previously referenced.

http://lawr.ucdavis.edu/classes/ssc102/

Pay particular attention to sections 3, 6-8.

With respect to P, please check up on solubility constants of different P species/compounds and how that may or may not affect availability at low pH. Once again, these micro/macro nutrient problems with respect to high soil P are mostly associated with high pH soils, not low, as is the case here.

With respect to current ph, this is a non factor simply because once you start applying the liming materail, the ph is going to change and should go up. Also when applying the lime the tripple negatively charged P is going to start attaching to the double positively charged just applied free calcium. This isnot going to change the ppm found of P, it is simply going to make some of that P a little harder for the plants to pickup. High ph is usually associtated with soils with either high Ca or Mg levels altho Na as well as K can also cause high ph readings.



SOC (soil organic carbon) is not comprised of strictly humus (humic compounds). Also, you cannot compare a "soil" comprised strictly of humus to one that is a mix of humus and mineral components. Where are you getting this information?

Also your same inputs and productivity example does not pan out. Why would you apply the same inputs on a soil with a higher CEC (i.e. nutrient retention) as a soil with low CEC?
A sandy soil can have very high CEC simply because of the high Om content and some clays can have low CEC because of a low Om content. If the CEC is the same for both soils, which would be the most fertile?


I think the more important relationship to draw is fewer inputs are required to get the same level of productivity in soils with higher CEC/SOM strictly due to better nutrient retention, soil structure, etc.... If anything, I would expect a decline in productivity in a strictly humus soil if fertilized at the same rate as, say a sandy soil, due to the potential for nutrient toxicity over time.

@Bill

Just because no "visible" improvement is noted does not mean there is not an improvement. More likely that not, a "visible" improvement was not noted because there were no limiting nutrients (i.e. luxury consumption was the case) or limiting conditions, not because the SOM was at 9%.

While we are at it, please define "enough available OM". Available for what?

Quote:
growingdeeprootsorganicly soil test... sul-po-mag + lime plus lots of post, that guys area receives lots of rain each year so to me mineral augmenting would be wise

a soil with high P and low pH one would think not have a micro nute issue simply because of the soil's pH. no?

pure clay soil vs humus soil...? mudd, i respectfully disagree again
And you just made a recommendation to apply sulfur without any reguard to the soiltest results. (Hint, sulfur was not reported on the soil test shown) So for that I will respectfully disagree with your recommendations.

Actually the addition of sulfur would probably also be necessary, I am just disagreeing because S was not a part of this soil sample and therefore it isnt possible to say whether or not S or any other nutrient is needed.

As for the clay and humis part of this discussion. Clay has about half the nutrient holding ability of pure humis and it isnt to likely that anybody would plant anything in a pure humis solution, altho I have in my greenhouse and results support my statements that plants potted in clay will outperform the plants potted in the humis. My point is simply that a mixture of humis and clay will make a better growing median than either of the materials by themselfs. There is a point of demished returns on how much humis is enough, for me its generaly around 7%, which seems to also be supported by ICTbills little story. Once enough has been applied, anything else would be a luxury and not necessary more productive.
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  #25  
Old 07-27-2009, 12:57 PM
Kiril Kiril is offline
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Quote:
Originally Posted by muddstopper View Post
With respect to current ph, this is a non factor simply because once you start applying the liming materail, the ph is going to change and should go up. Also when applying the lime the tripple negatively charged P is going to start attaching to the double positively charged just applied free calcium. This isnot going to change the ppm found of P, it is simply going to make some of that P a little harder for the plants to pickup.
There is only a need for about a half unit change in pH to bring it within "acceptable" levels (around 6.00). I would not be concerned about P availability until the pH is around 7.00 and higher, or below 5.00. Regardless of what species P forms with other cations at that pH (~ 6.00), IMO they will still largely be plant available (i.e. not locked up in "insoluble" compounds) at the current and potential target pH.

Quote:
Originally Posted by muddstopper View Post
High ph is usually associtated with soils with either high Ca or Mg levels altho Na as well as K can also cause high ph readings.
Once again, these cations do not change/cause pH.

Quote:
Originally Posted by muddstopper View Post
A sandy soil can have very high CEC simply because of the high Om content and some clays can have low CEC because of a low Om content. If the CEC is the same for both soils, which would be the most fertile?
You have not considered pH. Organic matter carries a pH dependent charge, which increases with increasing pH. Clays can be either pH dependent, permanent, or both, however is typically more stable with respect to CEC and changes in pH. While organic matter may potentially contribute more to a soils CEC (pH dependent), it alone does not define what a soils CEC is.

You also have not considered soil structure and parent material contributions to plant available nutrients. Once again, you do not judge a soils fertility on CEC alone. Now if you have said, which soil can retain nutrients better, then that would have been better, but still depends on other dynamics of the system such as soil moisture & other water relations, temperature, gaseous exchange, pH, structure, etc...

Quote:
Originally Posted by muddstopper View Post
As for the clay and humis part of this discussion. Clay has about half the nutrient holding ability of pure humis
This may or may not be true. Could you please define humus as you see it?
IMO, compost is not humus (per SSSA), however it can/will contain humic substances.
Compost: Organic residues, or a mixture of organic residues and soil, that have been mixed, piled, and moistened, with or without addition of fertilizer and lime, and generally allowed to undergo thermophilic decomposition until the original organic materials have been substantially altered or decomposed. Sometimes called "artificial manure" or "synthetic manure." In Europe, the term may refer to a potting mix for container-grown plants.

Humus: The well decomposed, more or less stable part of the organic matter in mineral soils. Humas is an organic soil material which is also one of the USDA textures of muck (sapric soil material), mucky peat (hemic soil material), or peat (fibric soil material.) Most likely it is muck.

Humic Substances: A series of relatively high-molecular-weight, yellow to black colored organic substances formed by secondary synthesis reactions in soils. The term is used in a generic sense to describe the colored material or its fractions obtained on the basis of solubility characteristics. These materials are distinctive to soil environments in that they are dissimilar to the biopolymers of microorganisms and higher plants (including lignin). See also humic acid, fulvic acid, and humin.
Quote:
Originally Posted by muddstopper View Post
and it isnt to likely that anybody would plant anything in a pure humis solution, altho I have in my greenhouse and results support my statements that plants potted in clay will outperform the plants potted in the humis. My point is simply that a mixture of humis and clay will make a better growing median than either of the materials by themselfs. There is a point of demished returns on how much humis is enough, for me its generaly around 7%, which seems to also be supported by ICTbills little story. Once enough has been applied, anything else would be a luxury and not necessary more productive.
This is anecdotal, not scientific. To state the above you need to present methodology, environmental conditions, data, etc... to support that statement. Just as in Bills case, an "observation" without knowing why is meaningless. Your observation could be completely unrelated to OM%. One example might be higher soluble salts in one over the other leading to lower productivity.

Furthermore, you have presented an unrealistic scenario, one of all "humus" (I assume you mean compost), and one of all clay (I assume you mean your native soil). We will never have an all compost case in a landscape .... well at least I would hope that will never happen, so why would you make that comparison?

With respect to Bills story, it illustrates nothing more than an unscientific conclusion made about the virtue of compost based on a "visual" assessment. Lets not even mention that the vast majority of the months between application and this "observation" were in the winter when essentially nothing was going on, microbially or otherwise. The conclusion they drew is nothing short of ridiculous.

Do you know of any published studies that supports your OM > 7% results in a negative impact on productivity?

I'm not trying to bust your balls here, and generally I agree with most everything you post, however sometimes you speak in absolutes which are not appropriate given the complexity of the systems we are talking about.
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  #26  
Old 07-30-2009, 10:10 PM
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muddstopper muddstopper is offline
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Quote:
Originally Posted by Kiril View Post
Originally Posted by muddstopper
With respect to current ph, this is a non factor simply because once you start applying the liming materail, the ph is going to change and should go up. Also when applying the lime the tripple negatively charged P is going to start attaching to the double positively charged just applied free calcium. This isnot going to change the ppm found of P, it is simply going to make some of that P a little harder for the plants to pickup.

There is only a need for about a half unit change in pH to bring it within "acceptable" levels (around 6.00). I would not be concerned about P availability until the pH is around 7.00 and higher, or below 5.00. Regardless of what species P forms with other cations at that pH (~ 6.00), IMO they will still largely be plant available (i.e. not locked up in "insoluble" compounds) at the current and potential target pH.


Quote:
Originally Posted by muddstopper
High ph is usually associtated with soils with either high Ca or Mg levels altho Na as well as K can also cause high ph readings.

Once again, these cations do not change/cause pH.
In the above quote concerning ph, while i will agree with your statement that Ca, Mg, Na, K alone will not effect ph as they would need to be in a carbonate form. Lets not forget or overlook that my statement was concerning the application of a limeing material, specificly dolomite which is calcium and magnesium carbonate. Also if using this material to raise the base saturation to a specific level, once that specific level of saturation is achieved, the ph is going to raise more than one point. Your suggestion that ph6 is adequate might be true, but ph6 might not be optimum.


Quote:
Originally Posted by muddstopper
A sandy soil can have very high CEC simply because of the high Om content and some clays can have low CEC because of a low Om content. If the CEC is the same for both soils, which would be the most fertile?

You have not considered pH. Organic matter carries a pH dependent charge, which increases with increasing pH. Clays can be either pH dependent, permanent, or both, however is typically more stable with respect to CEC and changes in pH. While organic matter may potentially contribute more to a soils CEC (pH dependent), it alone does not define what a soils CEC is.

You also have not considered soil structure and parent material contributions to plant available nutrients. Once again, you do not judge a soils fertility on CEC alone. Now if you have said, which soil can retain nutrients better, then that would have been better, but still depends on other dynamics of the system such as soil moisture & other water relations, temperature, gaseous exchange, pH, structure, etc...
. You are exactly right, my point being that just using the CEC and organic content isnt a good way to judge soil fertility and therefore there is noway of giving the correct answer to my question, simply not enough information has been provided. Even with the soil test results that where provide, some here have made recommendations to use certain products that the soiltest results in no way supports or provides enough information to make a proper determination if those amendments are even needed.

Quote:
Originally Posted by muddstopper
As for the clay and humis part of this discussion. Clay has about half the nutrient holding ability of pure humis

This may or may not be true. Could you please define humus as you see it?
IMO, compost is not humus (per SSSA), however it can/will contain humic substances.

Compost: Organic residues, or a mixture of organic residues and soil, that have been mixed, piled, and moistened, with or without addition of fertilizer and lime, and generally allowed to undergo thermophilic decomposition until the original organic materials have been substantially altered or decomposed. Sometimes called "artificial manure" or "synthetic manure." In Europe, the term may refer to a potting mix for container-grown plants.

Humus: The well decomposed, more or less stable part of the organic matter in mineral soils. Humas is an organic soil material which is also one of the USDA textures of muck (sapric soil material), mucky peat (hemic soil material), or peat (fibric soil material.) Most likely it is muck.

My definition of humis more or less is the same as the one you provided

Humic Substances: A series of relatively high-molecular-weight, yellow to black colored organic substances formed by secondary synthesis reactions in soils. The term is used in a generic sense to describe the colored material or its fractions obtained on the basis of solubility characteristics. These materials are distinctive to soil environments in that they are dissimilar to the biopolymers of microorganisms and higher plants (including lignin). See also humic acid, fulvic acid, and humin.
Quote:
Originally Posted by muddstopper
and it isnt to likely that anybody would plant anything in a pure humis solution, altho I have in my greenhouse and results support my statements that plants potted in clay will outperform the plants potted in the humis. My point is simply that a mixture of humis and clay will make a better growing median than either of the materials by themselfs. There is a point of demished returns on how much humis is enough, for me its generaly around 7%, which seems to also be supported by ICTbills little story. Once enough has been applied, anything else would be a luxury and not necessary more productive.

This is anecdotal, not scientific. To state the above you need to present methodology, environmental conditions, data, etc... to support that statement. Just as in Bills case, an "observation" without knowing why is meaningless. Your observation could be completely unrelated to OM%. One example might be higher soluble salts in one over the other leading to lower productivity.

Furthermore, you have presented an unrealistic scenario, one of all "humus" (I assume you mean compost), I didnot mean compost, I meant humis as in your definiton above, or at least as close as i could find.and one of all clay (I assume you mean your native soil).There are many types of clay, but yes, I am refering to my native soil. We will never have an all compost case in a landscape .... well at least I would hope that will never happen, so why would you make that comparison?

With respect to Bills story, it illustrates nothing more than an unscientific conclusion made about the virtue of compost based on a "visual" assessment. Lets not even mention that the vast majority of the months between application and this "observation" were in the winter when essentially nothing was going on, microbially or otherwise. The conclusion they drew is nothing short of ridiculous.

This observation can be seen in situations when using all the curealls, one lb treats an acre, biostimulants and humate products. In soils with extremely low organic matter, some of the magic products will work to some extent and benefits are obtained, but once that same product is applied to a high Om soil, which already contains sufficient humic substances, the additional benefits never materialize. Simply put, if your soil already has a high Om content, it already contains the humic fractions found in the products you are applying, therefore, a few ounces of addition material, is pretty much a waste of time and money. Visul differences are what most people judge the effectiveness of any product, whether its chemical ferts or compost. Raiseing Om content with the use of these product from 7%, or from even 4% by a .00000something% is at best a feelgood, Ive done something for the enviroment so now I am green, folley. I am not calling all those advertised curealls a snakeoil product, but one needs to understand when these products might and mightnot work and why they do and donot work for different users.

Do you know of any published studies that supports your OM > 7% results in a negative impact on productivity? It might take me a little research to find this information source again, not sure it was a published study, but I will look and see if I can supply a link.

I'm not trying to bust your balls here, and generally I agree with most everything you post, however sometimes you speak in absolutes which are not appropriate given the complexity of the systems we are talking about.

Good point about the absolutes, not my intentions to make everything seem so black and white. A case of hardheadness I guess. In the same sentence, not all of us can interpet all those chemical equations you like to provide. You could provide a link to the perfect solution to all of our fertility problems, but if that information is written in chinese, it is of no use to a lot of us here. Not busting your balls on what you do, because the information you provide is valuable, its just usually over my educational level. I do attempt to read an try to understand most of it. It usually takes me a while and a lot more research to do so. Maybe sometime you could take the time to simplify or explain what some of the material is actually saying.

............
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  #27  
Old 07-31-2009, 12:22 AM
Kiril Kiril is offline
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Originally Posted by muddstopper View Post
Your suggestion that ph6 is adequate might be true, but ph6 might not be optimum.
IMO, for landscapes it doesn't have to be optimum, or anything even close to optimum. Get your pH to a level where your inputs are reduced. If your soils already have the nutrients there, then there is no need to add more. Anything in the 5.7-6.3 range generally speaking is good enough IMHO.

Quote:
Originally Posted by muddstopper View Post
Also if using this material to raise the base saturation to a specific level, once that specific level of saturation is achieved, the ph is going to raise more than one point.
You think? It doesn't have to be a perfect ratio, that "rule" is an extremely general one. The target here should be getting pH to around 6, not achieving the perfect base saturation. I thought you were in the SLAN camp anyhow ... why would you care about optimal base saturation?

Quote:
Originally Posted by muddstopper View Post
Even with the soil test results that where provide, some here have made recommendations to use certain products that the soiltest results in no way supports or provides enough information to make a proper determination if those amendments are even needed.
Agree.

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Originally Posted by muddstopper View Post
but once that same product is applied to a high Om soil, which already contains sufficient humic substances, the additional benefits never materialize.
I asked Bill this, but I'll ask you as well. What is sufficient, in what type of soil, and to what depth? Personally I would like to see a consistent OM% in at least the top 8-12", regardless of what you are growing. You may have "sufficient" OM in the top 1-2", but we don't want our effective roots zones to be restricted to that depth, do we? Part of effective land management is utilizing the native soils and the resources they have to offer. This means promoting and developing good soils at a depth greater than 1-2". The only way to achieve this is by continued inputs of organic matter, assuming your typical mineral landscape soil with almost no OM.

Quote:
Originally Posted by muddstopper View Post
Visul differences are what most people judge the effectiveness of any product, whether its chemical ferts or compost.
While this may unfortunately be true, it doesn't make it right. We as industry professionals, who should know better, should not cater to public misperception. In my eyes, if I can go an entire season with zero inputs, or even a 75% reduction, due to a compost application with an over seed in the fall, that is a major benefit which not only continues to promote soil health and development, but saves money.

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Maybe sometime you could take the time to simplify or explain what some of the material is actually saying.
I have tried to think of a way to put it simpler, without much success.
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  #28  
Old 07-31-2009, 09:34 AM
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Originally Posted by Kiril View Post
IMO, for landscapes it doesn't have to be optimum, or anything even close to optimum. Get your pH to a level where your inputs are reduced. If your soils already have the nutrients there, then there is no need to add more. Anything in the 5.7-6.3 range generally speaking is good enough IMHO.
I can agree with that, up to a point, but I can get a ph of 6.3 using sodium in a acid soil. Just because a soil has a good ph doesnot mean that soil is fertile. One must look at what element is driving those ph numbers. One could apply dolomite lime to the point that the Mg is driving the ph upward and still not have sufficient calcium to support good plant growth, even tho the ph would be considered perfect



You think? It doesn't have to be a perfect ratio, that "rule" is an extremely general one. The target here should be getting pH to around 6, not achieving the perfect base saturation. I thought you were in the SLAN camp anyhow ... why would you care about optimal base saturation?
What is the SLAN camp? not sure what you mean . At anyrate, I study the Abretch Method of soil fertility which is based on base saturations and having enough available nutrients without excesses. Where each nutrient has a direct effect on other nutrients. Where not only the laws of minimum nutrients apply, but also the laws of the maximums. ratios are meaningless if you dont have enough of either nutrient to provide nurishment to the plant. What good is a perfect ph if it is being driven by the wrong nutrients.







I asked Bill this, but I'll ask you as well. What is sufficient, in what type of soil, and to what depth? Personally I would like to see a consistent OM% in at least the top 8-12", regardless of what you are growing. You may have "sufficient" OM in the top 1-2", but we don't want our effective roots zones to be restricted to that depth, do we? Part of effective land management is utilizing the native soils and the resources they have to offer. This means promoting and developing good soils at a depth greater than 1-2". The only way to achieve this is by continued inputs of organic matter, assuming your typical mineral landscape soil with almost no OM.
You can build OM faster farming microbes than you can adding compost. Om depth inthe soil is limited to how deep the air supply can go. The top few inches is usually where the most abundance of O2 can be found, decreaseing with depth. Anything that can be done to increase O2 in the lower levels of the soil will increase the biology in the soil. The plowing of fields increases O2 levels in the soil and stimulates microbial activity, resulting in a decrease in soil humis due to microbial consumption. The net result is a loss of carbon thru O2 to CO2 conversions. The trick is to increase microbial levels without a decrease in carbon. This requires extra imputs of food source for the microbes. Compost is one tool. Considering that an acre of soil 6 inches deep weighs around 2million lbs, raiseing the OM by even 1% is going to take a lot of organic materials. When you also factor in the conversion and weight loss from the breakdown of organic materials to compost and then down to humis, this amount needed is way more than one would apply and could be cost prohibiting if you arenot making it yourself. Correcting a soils chemical makeup will improve the physical characteristis and promote a better enviroment for the biology, but microbes are just like humans in a sense, you cant feed them pure sugar and expect them to have a healthy population. And just because you are using compost to feed your soil doesnt mean you are suppling all the proper nutrients. If the organic material from which the compost is derived from is lacking in a specific nutrient, so then will the compost. Ask youself this, would you rather have compost made from lumbershavings? or from the tree bark? Or both? Which material would have the better balance of nutrients?



While this may unfortunately be true, it doesn't make it right. We as industry professionals, who should know better, should not cater to public misperception. In my eyes, if I can go an entire season with zero inputs, or even a 75% reduction, due to a compost application with an over seed in the fall, that is a major benefit which not only continues to promote soil health and development, but saves money.



I have tried to think of a way to put it simpler, without much success.
............
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  #29  
Old 07-31-2009, 12:09 PM
Kiril Kiril is offline
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Originally Posted by muddstopper View Post
I can agree with that, up to a point, but I can get a ph of 6.3 using sodium in a acid soil.
Perhaps, if you use sodium (bi)carbonate.

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Originally Posted by muddstopper View Post
Just because a soil has a good ph doesnot mean that soil is fertile.
Who said anything to the contrary? I will add here that just because you have an "ideal" base saturation also does not mean a soil is fertile.

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Originally Posted by muddstopper View Post
One must look at what element is driving those ph numbers.
HUH? What elements other than hydrogen are an option when we are talking acidity? The point in adding lime is to remove hydrogen from the exchanger so it can react with the carbonate, which essentially removes it from the active pool (i.e. it no longer contributes to the acidity of the soil).

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Originally Posted by muddstopper View Post
One could apply dolomite lime to the point that the Mg is driving the ph upward and still not have sufficient calcium to support good plant growth, even tho the ph would be considered perfect
There is already more than enough Ca for turf, so it is not a concern. In fact, the only reported nutrient that I see which has the potential to become limiting in the short term is potassium.

Quote:
Originally Posted by muddstopper View Post
What is the SLAN camp? not sure what you mean
Sufficient Levels of Available Nutrients - i.e. determine what is needed by individual nutrient analysis, not using ideal base cation ratios.

Not that I am one to typically use the USGA as a reference (damn turf promoters), but this pub covers the issue.

http://www.usga.org/turf/green_secti...saturation.pdf

Quote:
Originally Posted by muddstopper View Post
At anyrate, I study the Abretch Method of soil fertility which is based on base saturations and having enough available nutrients without excesses. Where each nutrient has a direct effect on other nutrients. Where not only the laws of minimum nutrients apply, but also the laws of the maximums. ratios are meaningless if you dont have enough of either nutrient to provide nurishment to the plant. What good is a perfect ph if it is being driven by the wrong nutrients.
Not following you Mudd. Why are you hung up on providing sufficient nutrients (SLAN) if your approach is management via base saturation (BCSR)? The two approaches are not the same. Either you follow Albrecht's theory or you don't. IMO base saturation is more important with respect to soil structure and subsequently overall soil health than it is for nutrients. You yourself have said on many occasions just because you have the correct ratio does not mean you have sufficient nutrients. Personally I use both methods when making management decisions based on a soil test. SLAN to address nutrient needs, BCSR for overall soil structure and health.

So lets look at the OP's soil again. What would be the reason for adding lime if it was not for raising pH? Just to get your base saturation "optimal"? Is there a visible Ca deficiency in the ops turf? Is there a problem with soil structure due to high levels of Mg or Na? No indication of either has been given by the OP or the soil test.

If you really want to play the ratio game, both Ca and Mg levels are sufficient for turf (ppm) and the ratio is 6:1, which is close enough to "ideal" IMO. The only good reason for adding lime would be to increase pH which will lead to better overall nutrient availability. As a bonus you get your base saturation into a more "ideal" range, if that is what you are concerned with. Doesn't really matter how you look at it ... correcting one "problem" will correct both.

Now one needs to understand here that an addition of lime in this case needs to come with an addition of potassium as well because the addition of lime will more likely than not result in potassium becoming limiting. If you want to kill two birds with one stone, then amend with wood ashes.

BTW, "nutrients" don't necessarily drive a systems acidity. Potential causes of soil acidity are environment (areas of high precipitation), decomposition of SOM (CO2), parent material & soil type, management practices, etc.... Soils low in OM & clay are more likely to be acid in areas where rain is plentiful because they are highly leached.

Quote:
Originally Posted by muddstopper View Post
You can build OM faster farming microbes than you can adding compost.
HUH! Compost not only adds microbes but adds a food source too. Can't have a microbe farm and build SOM without food source now can you?

Quote:
Originally Posted by muddstopper View Post
The top few inches is usually where the most abundance of O2 can be found, decreaseing with depth.
Generally true, but HIGHLY dependent on the soil type and structure. With respect to the rest ... ?

Compost is applied primarily as a source of SOM/SOC, secondarily as a source of nutrients. If the compost is lacking in a particular nutrient that is needed, then obviously that will need to be addressed. The reason why you keep applying it is because it does take a lot to make a difference to a sufficient depth.

Top dressing compost is the typical practice in landscapes, which means vertical movement of OM will take a long time, how long depends on the soil and environmental conditions. You cannot promote better soil structure and subsequent microbial activity if you don't have a continued source of OM.

Might I also point out once again we are talking about landscapes here, NOT Ag.

Ideal/optimal soil available nutrients is NOT a requirement for landscapes. There is absolutely NO need to manage a landscapes soil (with respect to nutrients) the same as you would in Ag.
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Old 07-31-2009, 02:18 PM
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DUSTYCEDAR DUSTYCEDAR is offline
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compost always seems to help but it takes time
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