ADHD in Research

[Smallaxe]

While looking for Articles about Charcoal, by Nick Christians, I come across this:

http://www.turfgrasstrends.com/turfgrasstrends/Fertilizer/Is-Reducing-Soil-pH-Possible/ArticleLong/Article/detail/64595?contextCategoryId=1413

** "Acidity in the soil results from the leaching of exchangeable base-forming cations calcium (Ca+2), magnesium (Mg+2), potassium (K+) and sodium (Na+) from the upper soil horizon. Hydrogen (H+) and aluminum (Al+3) remain as the primary cations in these soils."

So the point here is that acid soils are 'acid' because they are long on H+ and Al+3 cations.

** "Under strong acidic soil conditions (a pH of less than 5) adsorbed Al+3 solubilizes and enters soil solution where it reacts with water to form aluminum hydroxide (Al(OH)+2) and H+.
...the acidity generated by iron is much less than that of aluminum. Adsorbed H+ actually contributes little to the pH of acid soils because it's tightly bound to organic matter...

Is this the reason for the popular idea, that OM is a great buffer, against the extremes of pH?

Now if *(Al(OH)+2) and H+.*, is formed with water, like they say... doesn't that mean that some H+ ions are being used in the acid and the rest is being bound up in the OM?
Is that how we come to the definition of - "Low pH" or "Low potential Hydrogen"?

Any answer that could help me wrap my mind around some of this stuff would be helpful. :)

[Smallaxe]

Well that stinks... How about this then.

Is this statement true?

"Alfalfa and sweet clover would grow well on slightly acidic soils provided they were supplied with calcium, and acid-loving plants could thrive under alkaline soil conditions if supplied with micronutrients (Tisdale et al., 1993).

"Turfgrass and landscape managers are usually overly concerned about the pH of the alkaline soils that they are managing... ...usually not necessary."

This would be good for us to know if we are to be able, as a Pro, to give proper advice and treatment.

[Kiril]

Don't know what you are looking for Axe. Your questions have already been answered in this forum on several occasions, in threads I am sure you have seen and possibly even participated in.

[Smallaxe]

Don't know what you are looking for Axe. Your questions have already been answered in this forum on several occasions, in threads I am sure you have seen and possibly even participated in.

That is very true. Those discussions convinced me I didn't know, even the little bit I thought I knew, about the essentials of pH. I don't remember a consensus on many things being arrived at, which left me more confused, than enlightened.

So at this point, I am trying to put together a picture in my mind's eye, as to what is actually taking place at the molecular level, which is causing this phenomena... but perhaps, that is not necessary.

If higher OM can buffer pH adequately, and we can simply apply more nutrients to the turf, more often, to achieve the desired end; then pH really becomes a non-factor in our management programs. Getting the nutrients to the plant, b4 they get tied in the soil, due to pH issues, seems to be the challenge... is that true?

I do not communicate thoughts very well, sometimes, so if this is nothing more than a rambling to you, I understand. :)

[Kiril]

That is very true. Those discussions convinced me I didn't know, even the little bit I thought I knew, about the essentials of pH. I don't remember a consensus on many things being arrived at, which left me more confused, than enlightened.

So at this point, I am trying to put together a picture in my mind's eye, as to what is actually taking place at the molecular level, which is causing this phenomena... but perhaps, that is not necessary.

If higher OM can buffer pH adequately, and we can simply apply more nutrients to the turf, more often, to achieve the desired end; then pH really becomes a non-factor in our management programs.

Well, yes and no. Personally I don't fixate on pH, however in order to manage a soil you need to be aware of what a given pH will do to nutrient availability. The reason why OM buffers pH well is due to it's high pH dependent CEC.

Getting the nutrients to the plant, b4 they get tied in the soil, due to pH issues, seems to be the challenge... is that true?

Keeping adequate levels of exchangeable nutrients is more the challenge IMO.

I've posted this before, but if you really want to know what is going on you should try to understand this.

http://lawr.ucdavis.edu/classes/ssc102/Section7.pdf

[Smallaxe]

Well, yes and no. Personally I don't fixate on pH, however in order to manage a soil you need to be aware of what a given pH will do to nutrient availability. The reason why OM buffers pH well is due to it's high pH dependent CEC.



Keeping adequate levels of exchangeable nutrients is more the challenge IMO.

I've posted this before, but if you really want to know what is going on you should try to understand this.

http://lawr.ucdavis.edu/classes/ssc102/Section7.pdf

Thanks, I'll study this.

[ecoguy]

A while back we were discussing whether or not a lawn could be sustained by compost alone. I asked Paul Tukey this same question and he said that because compost has little to no nitrogen it is important to insure the grass still has an adequate N supply. He said by recycling the clippings you will be supplying 25%-50% of the N for the year. I'm a spring application of CGM could supply the rest as well as deter potential crabgrass/dandelions. Sounds like a natural system to me.

Btw - this note probably doesn't belong here...:)

[phasthound]

A while back we were discussing whether or not a lawn could be sustained by compost alone. I asked Paul Tukey this same question and he said that because compost has little to no nitrogen it is important to insure the grass still has an adequate N supply. He said by recycling the clippings you will be supplying 25%-50% of the N for the year. I'm a spring application of CGM could supply the rest as well as deter potential crabgrass/dandelions. Sounds like a natural system to me.

Btw - this note probably doesn't belong here...:)

That's pretty much the same program touted by Mike McGrath on NPR's You Bet Your Garden. CGM in spring, leave clippings all year, compost top dress & seed in fall.

[Smallaxe]

A while back we were discussing whether or not a lawn could be sustained by compost alone. I asked Paul Tukey this same question and he said that because compost has little to no nitrogen it is important to insure the grass still has an adequate N supply. He said by recycling the clippings you will be supplying 25%-50% of the N for the year. I'm a spring application of CGM could supply the rest as well as deter potential crabgrass/dandelions. Sounds like a natural system to me.

Btw - this note probably doesn't belong here...:)

Corn has become anything , but eco-friendly, especially, since it isn't even natural anymore. All the fossil fuels, NPK, huge amounts of herbicide, etc. etc., and you believe its is eco friendly, to ship it to your house, so that you can let it rot on the ground.

It doesn't bother me personally, but it is antithetical to the whole eco ideal. Don't ya think?