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Cubguy
09-09-2007, 04:53 PM
Do to alkaline clay soil I was told to use pine mulch around a southern magnolia to help make the soil more acidic. Also used it around some crept Myrtle trees. Now I hear the pine mulch ties up up nutrients in the soil. These are new plantings on that we are trying to get max growth.

Thanks for any help on this!

Paul

Marcos
09-09-2007, 05:29 PM
It does. I worked at an arboretum here in southern OH for a number of years and they used nothing but Scotch pine needles in the volunteer beds. They CONSTANTLY had to foliar feed due to the effects of the mixing of the acidic needles with the soil. Man, it's worth it though. They last FOREVER if you're careful not to blow them away with a blower. That's what I use at my place now, almost everywhere. I only mulch my front yard areas once every 5-6 years, and I have living mulch-machines growing in the back!

Focal Point Landscapes
09-09-2007, 11:00 PM
What is the source of your info ? I know empirically that pinestraw has been used for mulch throughout the south for decades with no negative effects on plant growth , for all types of plants .

Marcos
09-10-2007, 11:08 AM
What is the source of your info ? I know empirically that pinestraw has been used for mulch throughout the south for decades with no negative effects on plant growth , for all types of plants .

Well. To expand on the point: The plants, perennials mostly, were lackluster and yellow in the margins. The arboretum director and I had worked with CLC Labs in Westerville OH on the issue, and Chuck Darrah at CLC used a number of the very high pH samples ( probably 7.7 to 7.9) taken from the arboretum to draw his conclusion. We also sent plant tissue samples to Ohio State University to clarify the exact nutrients that were deficient. O.S.U. determined in writing that unless measures were not made to lower pH (which wasn't going to happen because of certain stupid politics at the time) that supplemmetal feedings of micronutrients of Fe, Mn, Mg, would be needed. This is an area of limestone / dolomite subsoil and bedrock and we sit at the very southernmost edge of the last glacial advance, so it's important to ask CLC for help when there's an issue like this. The conlusion was and is that it works HERE.

YardPro
09-10-2007, 09:22 PM
Marcos,
the pine needles were NOT the cause of the problems they had...

pine needles will acidify the soils but break down very rapidly. If your soil is already acidic pH<5.5 then they would not be a good choice because they would further acidify the soil and would "tie up" certain micronutrients.

If you have a high pH like the one Marcos is describing then pine needles are a great choice. The reason marcos's plants were yellow is because at that high of a pH Iron is sequestered and unavailable to the plant. The chlorophyll molecule has an iron molecule at it's core just like hemoglobin. Less iron = less chlorophyll= less green............the reason had nothing to do with pine needles, it was the conditions that you described in the second post.

We fight high pH soils here all the time our soil is 7.5-9.... pine needles are a good way to acidify the soils..


to determine if the needles are good or bad for you check your pH.

Focal Point Landscapes
09-10-2007, 09:49 PM
Thanks for the explanation , Yardpro .

Marcos
09-11-2007, 01:03 AM
Marcos,


pine needles will acidify the soils but break down very rapidly.
to determine if the needles are good or bad for you check your pH.

Well, first of all. I never said the pine needles were the CAUSE of the problem.
I simply indicated that they were the PREFERENCE of the volunteers at the arboretum then (and myself now). On the contrary, we knew the pH was high, and tried like hell to talk the volunteer committee into using split pea sulfur in several split applications in an attempt to help lower it in addition to the gradual natural work of the pine straw. But if you've ever worked with groups of SENIOR CITIZEN VOLUNTEERS..... :cry: :dizzy: you get the picture? Also: Up here, Scotch pine needles tend to be MUCH more rot resistant than anything I've ever seen, incuding Austian or White pine.

Cubguy
09-11-2007, 11:46 PM
Thanks for the input guys. Down here in South Texas the pine mulch readily available is lumber byproducts from the lumber mills it looks like ground up lumber. I guess from the posts that it only becomes a problem when the PH gets too acidic.

Cubguy

YardPro
09-12-2007, 07:41 AM
Well, first of all. I never said the pine needles were the CAUSE of the problem.
I simply indicated that they were the PREFERENCE of the volunteers at the arboretum then (and myself now). On the contrary, we knew the pH was high, and tried like hell to talk the volunteer committee into using split pea sulfur in several split applications in an attempt to help lower it in addition to the gradual natural work of the pine straw. But if you've ever worked with groups of SENIOR CITIZEN VOLUNTEERS..... :cry: :dizzy: you get the picture? Also: Up here, Scotch pine needles tend to be MUCH more rot resistant than anything I've ever seen, incuding Austian or White pine.


yes you did... read the very first sentence of your original post....you responded that pine needles do tie up nutrients.........

they do not, especially in alkaline soils

Marcos
09-12-2007, 11:15 AM
yes you did... read the very first sentence of your original post....you responded that pine needles do tie up nutrients.........

they do not, especially in alkaline soils

Hey! The 'Last Word Syndrome' looms large here!!! Has my ex wife taken up the handle of Yard Pro ??? :laugh: :laugh: :laugh:

Smallaxe
09-13-2007, 10:14 AM
One last word :) Any raw material 'in" the soil that is in the process of decay ties up N. Mulch on "top" of the soil should not impact root zones in that sense.

YardPro
09-14-2007, 06:54 PM
not accurate.

the reason you would make that statement is that the material you describe has yet to have it's N released by the nitrogen fixing bacteria.

the material would have no effect on N already present in the soil.

jeffinsgf
09-14-2007, 07:14 PM
Thanks for the input guys. Down here in South Texas the pine mulch readily available is lumber byproducts from the lumber mills it looks like ground up lumber. I guess from the posts that it only becomes a problem when the PH gets too acidic.

Cubguy

In a thread that has seen some serious confusion, here is some more.

Ground up construction lumber is among the worst mulch you can buy, and an open invitation to termites.

When someone recommended pine mulch to you, they were talking about pine straw -- which is pine needles gathered and baled like straw or hay. It is a very attractive, easily managed mulching material, found predominantly in the South. It will acidify the soil, as will any evergreen mulch, and since they break down very slowly, they do not rob nitrogen from the soil at the same rate as hardwood mulch.

I love pine straw, but I am north of where it is readily available. Every time I have an empty trailer in the South, I pick some up. When that's not convenient, I use Eastern Red Cedar (juniper) chips that I run through my chipper shredder.

Smallaxe
09-15-2007, 11:06 AM
not accurate.

the reason you would make that statement is that the material you describe has yet to have it's N released by the nitrogen fixing bacteria.

the material would have no effect on N already present in the soil.

This is the first time I have ever heard that. I have always heard what the previous poster stated "rob nitrogen from the soil".
Is there a website or something that would provide a definitive answer?

YardPro
09-15-2007, 09:17 PM
LOL, not true...

my degrees are in biology ( physiology, anatomy, and cellular biology).....I got this all from my classes...

nitrogen becomes available to plants after nitrogen fixing bacteria process material. Nitrogen is a waste product of most animals (and about 76% or the air in the atmosphere). the bacteria convert the nitrogen to forms that plants can uptake.
once the nitrogen is converted ( remember it is a waste product... bacteria poop), it is no longer used by the bacteria.

the only thing that would affect the available nitrogen in the soil after that would be soil chemistry. some forms of nitrogen (NO3-, and NH4+) are ionic and will react with polar molecules in the soil. one of the other forms (NH3) is a gas and escapes into the atmosphere. microbial activity has no affect on them as they are the end products of bacterial activity.

Smallaxe
09-16-2007, 10:12 AM
That logic makes sense to me. I had always heard it the other way and everyone seemed to agree that it was true, but never heard 'how' it happens.
I do notice however that when I stir in a new batch of woodchips that the weed are more pale in those areas. The garden seems ok by the following spring. I assumed the tied up N during breakdown.
If not that, what would be the cause? Same soil in the same garden, but paler weeds in the new chip area?
I'm curious now. :)

YardPro
09-16-2007, 02:47 PM
That logic makes sense to me. I had always heard it the other way and everyone seemed to agree that it was true, but never heard 'how' it happens.
I do notice however that when I stir in a new batch of woodchips that the weed are more pale in those areas. The garden seems ok by the following spring. I assumed the tied up N during breakdown.
If not that, what would be the cause? Same soil in the same garden, but paler weeds in the new chip area?
I'm curious now. :)


this happens for a few reasons.

one is lower oxygen penetration in the subsoils (very temporary).

any mulch will absorb rainfall ( a frequent source of nitrogen. Rain passes through the air which is 76% N, and absorbs a significant amount of N.) This can slow the nitrogen incorperation into the soil. Also if fertilizer is applied on top of new mulch the mulch will absorb some of the water that has fertilizer dissolved in it, so for these two examples yes, it can tie up these sources of N.

Back to the reason for the yellowing weeds, as you apply new mulch the new roots of weeds grow up towards the surface where there are less nutrients (decomposed material)