Need pH help!

stormymater · July 8, 2009

I purchased a topsoil blend this spring to go into 3 4x12 foot raised beds we built. The topsoil blend was supposedly - topsoil, compost, 10% turkey manure - pH adjusted to 6.5.
Loaded & prepped beds & used it in my many grow bags. Plants just sat there - looking green & healthy but no real growth. The black tomatoes were planted in one of our old beds - loamy sand (it is the beach) augmented with compost from leaves, pine needles, horse manure & untreated wood shavings. The black tomato plants are 4 feet tall & loaded with tomatoes (up to 20+ on some plants - not the Cherokee Chocolate though) while the pink, red & bi-colored beds are 2- 2 1/2 feet tall with only 3 plants out of 30 having set any fruit at all. Same minimal growth in the grow bags loaded with the black soil.
All plants were planted with Tomato-Tone & Epsom salts in their planting holes. I sent soil in for soil analysis & have partial results on-line today. My pH in the black soil is 8 in the original unused pile (I had some leftover) & 7.7 & 7.6 in my pink & red tomato beds. The lab's recs are for - 1.0 lbs Nitrogen or equiv per 1000 SQ FT.

My 3 old beds have pH 7.4 & 2 beds are recommended to get - (7.0 lbs 15-0-14 or EQUIV PER 1000 SQ FT) - while the third bed recs are (12.5 lbs 8-0-24 or EQUIV PER 1000 SQ FT.

Questions - 1. what do I do to correct the pH/nitrogenopenia without burning up my plants?
2. How does pH affect nitrogen availability? Or, asked another way, can turkeys poop nitrogenopenic poop?
3. Think the place I bought the 14 cubic yards of soil from ought to make it right - eg, a log unit of pH closer to what they said the product would be (pH 6.5)

Any advice/recs greatly appreciated! TIA!

habitat_gardener · July 8, 2009

Did I misunderstand, or do the results recommend 7.5 pounds of N for the only bed that is producing greenies? That makes me question the validity of the whole report. I'd be looking for differences between the soil in the black-tomato bed vs. all the other soil to figure out what's going on.

Could the epsom salts have skewed the pH results?

My solution for all garden soil is compost and mulch. Compost will bring acidic/basic soil back toward neutral.

For the soil food web, anything over 10-10-10 is deleterious.

dice · July 8, 2009

High pH won't interfere with nitrogen uptake directly, but it
inhibits iron uptake and encourages phosphorus to become
insoluble dicalcium phosphate.

There is a guide for how much sulfur to use to lower pH with
Espoma Garden Sulfur at the bottom of this page:
http://homeharvest.com/soilconditionerspH.htm

(I would forget the fertilizer recommendations from the soil
test. What exactly are they expecting you to grow there, for
example? Lettuce, lemons, tomatoes, or none of the above?
Each would have different targets for final N-P-K ppm.)

stormymater · July 8, 2009

Thanks folks!
hg - I cut & pasted those recs 7# of 15-0-14 per 1000 sq feet - that would be divided by 20 for my 48 sq ft bed so 0.35# 15-0-14.

dice - thanks for the link - I have a 50# bag of magnesium sulfate. The report simply said "garden, vegetables" though I listed tomatoes for 4 of the 6 samples (beans & peppers for the other 2 specimens).

Can't figure how the N can be low in a mix that supposedly contained 10% poultry manure.

I put a call into the state soil sciences lab & will be speaking with one of the agronomist's next Monday (she's OOT until then). Will hold off on any dabbling until after we chat.

I also called the source of the soil - they reported their April 2009 pH test revealed a pH of 7.6. The salesman was flummoxed when I brought up the log scale difference between the purported pH at time of sale (6.5), my realities (8, 7.7, 7.6) & their confirmed test - 7.6. We'll see what happens.

dice · July 9, 2009

Magnesium sulfate (epsom salts) is not the same as "garden
sulfur", which is just sulfur. Sulfur is commonly used to lower
soil pH without changing the quantities of other nutrients
already present. Epsom salts are a near-neutral salt used
to add magnesium and sulfur without changing soil pH
significantly.

You can doubtless find sulfur in bulk at the same place that
had the 50# bag of magnesium sulfate, and if the soil supplier
offers a pH adjustment at their expense, that is probably what
they will send you.

hasshoes · July 9, 2009

I just skimmed and didn't see this added. . .

I think I read somewhere that the wrong ph for tomatoes can increase the likelihood of blossem end rot.

ps- wanted to add that I used an espoma product to lower my ph for rapsberries very quickly and it has worked REALLY great so far.

stormymater · July 9, 2009

thanks dice - I was uncertain of that. I have used garden sulfur for my blueberries last fall & then surrounded them with a deep pine needle mulch - they seemed to like it alot. If I hadn't tested the soil in the leftover pile (on a tarp behind the garden fence) I would've been wondering about the well water contributing to the alkalinity. The well taps a freshwater lens in coquina rock (limestone essentially).
hasshoes - I like Espoma products - have used 2 bags of Tomato Tone thus far this year LOL.

dice · July 9, 2009

As far as the nitrogen and potassium recommendations, I think
many of these soil tests can only detect what is soluble in the
soil right now. They may be able to make a guess as to how
much will weather out of rock sources of nutrients like rock
phosphate, greensand, langbeinite, granite dust, etc, based
on what percentages of the soil samples are those kinds of
rock, but they have no way to assess how much nitrogen
and potassium will be released by soils high in organic matter
as that organic matter decays (at least not without a lot more
expensive tests).

Those recommendations might make sense for a mostly
inorganic soil (sand and clay), where nothing much is going
to become available that is not already soluble in the soil.
That does not mean that the nitrogen and potassium
recommendations make sense for a mostly organic soil
enriched with compost and manure.

July 8, 2009	#1
stormymater Tomatovillian™ Join Date: Dec 2008 Location: Pleasure Island, NC 8a Posts: 1,162	Need pH help! I purchased a topsoil blend this spring to go into 3 4x12 foot raised beds we built. The topsoil blend was supposedly - topsoil, compost, 10% turkey manure - pH adjusted to 6.5. Loaded & prepped beds & used it in my many grow bags. Plants just sat there - looking green & healthy but no real growth. The black tomatoes were planted in one of our old beds - loamy sand (it is the beach) augmented with compost from leaves, pine needles, horse manure & untreated wood shavings. The black tomato plants are 4 feet tall & loaded with tomatoes (up to 20+ on some plants - not the Cherokee Chocolate though) while the pink, red & bi-colored beds are 2- 2 1/2 feet tall with only 3 plants out of 30 having set any fruit at all. Same minimal growth in the grow bags loaded with the black soil. All plants were planted with Tomato-Tone & Epsom salts in their planting holes. I sent soil in for soil analysis & have partial results on-line today. My pH in the black soil is 8 in the original unused pile (I had some leftover) & 7.7 & 7.6 in my pink & red tomato beds. The lab's recs are for - 1.0 lbs Nitrogen or equiv per 1000 SQ FT. My 3 old beds have pH 7.4 & 2 beds are recommended to get - (7.0 lbs 15-0-14 or EQUIV PER 1000 SQ FT) - while the third bed recs are (12.5 lbs 8-0-24 or EQUIV PER 1000 SQ FT. Questions - 1. what do I do to correct the pH/nitrogenopenia without burning up my plants? 2. How does pH affect nitrogen availability? Or, asked another way, can turkeys poop nitrogenopenic poop? 3. Think the place I bought the 14 cubic yards of soil from ought to make it right - eg, a log unit of pH closer to what they said the product would be (pH 6.5) Any advice/recs greatly appreciated! TIA!

July 8, 2009	#3
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	High pH won't interfere with nitrogen uptake directly, but it inhibits iron uptake and encourages phosphorus to become insoluble dicalcium phosphate. There is a guide for how much sulfur to use to lower pH with Espoma Garden Sulfur at the bottom of this page: http://homeharvest.com/soilconditionerspH.htm (I would forget the fertilizer recommendations from the soil test. What exactly are they expecting you to grow there, for example? Lettuce, lemons, tomatoes, or none of the above? Each would have different targets for final N-P-K ppm.) __________________ -- alias

July 9, 2009	#5
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	Magnesium sulfate (epsom salts) is not the same as "garden sulfur", which is just sulfur. Sulfur is commonly used to lower soil pH without changing the quantities of other nutrients already present. Epsom salts are a near-neutral salt used to add magnesium and sulfur without changing soil pH significantly. You can doubtless find sulfur in bulk at the same place that had the 50# bag of magnesium sulfate, and if the soil supplier offers a pH adjustment at their expense, that is probably what they will send you. __________________ -- alias

July 9, 2009	#6
hasshoes Tomatovillian™ Join Date: Jan 2007 Location: MT Posts: 438	I just skimmed and didn't see this added. . . I think I read somewhere that the wrong ph for tomatoes can increase the likelihood of blossem end rot. ps- wanted to add that I used an espoma product to lower my ph for rapsberries very quickly and it has worked REALLY great so far. __________________ Sara

July 9, 2009	#8
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	As far as the nitrogen and potassium recommendations, I think many of these soil tests can only detect what is soluble in the soil right now. They may be able to make a guess as to how much will weather out of rock sources of nutrients like rock phosphate, greensand, langbeinite, granite dust, etc, based on what percentages of the soil samples are those kinds of rock, but they have no way to assess how much nitrogen and potassium will be released by soils high in organic matter as that organic matter decays (at least not without a lot more expensive tests). Those recommendations might make sense for a mostly inorganic soil (sand and clay), where nothing much is going to become available that is not already soluble in the soil. That does not mean that the nitrogen and potassium recommendations make sense for a mostly organic soil enriched with compost and manure. __________________ -- alias

July 8, 2009	#2
habitat_gardener Tomatovillian™ Join Date: Apr 2008 Location: California Central Valley Posts: 2,540	Did I misunderstand, or do the results recommend 7.5 pounds of N for the only bed that is producing greenies? That makes me question the validity of the whole report. I'd be looking for differences between the soil in the black-tomato bed vs. all the other soil to figure out what's going on. Could the epsom salts have skewed the pH results? My solution for all garden soil is compost and mulch. Compost will bring acidic/basic soil back toward neutral. For the soil food web, anything over 10-10-10 is deleterious.