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Rochester

I know growers that add organic matter every year. If you fail to get a soil test done annually I would assume you can overdue it.what are the consequences of too much organic matter?

4/3/2019 12:03:41 PM

Colorado

More likely to get some fungal root diseases with OM super high.I consider 15% or higher super high.

4/3/2019 2:33:45 PM

Deer Park, WI

Mr. Scherber's comment about susceptibility to root diseases is spot on.

It also becomes more difficult to manage nutrients cost effectively. OM, by virtue of its properties, allows your soil to hold a higher amount of plant nutrients. Generally speaking, this is a good thing. However, if there is a significant imbalance in your nutrients, it will make it much more difficult & expensive to balance.

I continue to preach that 4-6% OM is the "goldilocks" sweet spot. Less this this, you may not hold enuf nutrient to meet plant need. More than this, you run into the issues described above.

4/3/2019 3:32:33 PM

Bethlehem CT

Good information, thanks Joe and Joze

4/3/2019 4:48:55 PM

Grittyville, WA

Question about OM: Is it really the amount of uncomposted OM that is the issue? Because if the uncomposted stuff is more than 3-5 % it can cause pathogens. But once its broken down to humus is why would there be any limit?

4/3/2019 5:52:52 PM

Grittyville, WA

Just to stir up trouble I think if I couldnt fertigate and had to go with what was in the soil, I would not be able to get enough nutrient resources unless the OM was 20%. Are most growers relying on chemical fertilizer for bulk of nutrients?

4/3/2019 5:59:00 PM

Grittyville, WA

I assume so!

4/3/2019 6:00:56 PM

Ireland

World records in the past 8 years have been grown on soil with 16% OM

4/3/2019 6:21:22 PM

JACKSON, WISCONSIN. ; )

16 % peat dirt... or another non soil growing media .. 6-8 % is very common

4/3/2019 9:23:49 PM

Morgantown, WV

I like the first couple comments. Too high, and water retention becomes an issue. Organic matter also holds far more cations (fertilizer molecules) than sand or silt, with clay holding the most, and far more than any other type of soil. This means, as Joe said, more amendments to cause the same effect.

If you are worried about soggy soil, or too much organic matter, tilling several times over a season can increase the decomposition of the OM that is there until you get to a better range. If your patch is low lying, digging will not help, build above grade.

If you'd like to start testing your soil on somewhat of a budget, send me an email. My lab runs full micronutrients panel and OM for $16.50, and I get results 3 days from mailing.

For what it's worth, I'm around 5% OM to start this year.

4/3/2019 10:15:19 PM

On top of Brush Mountain, Pa.

Joe, I don't agree with you about this. What you have not given enough consideration to is what the soil is like to begin with. I have almost no clay in my soil. So, to get my cation exchange content up I add a lot of organic matter to the soil. Without this higher level of organic matter my soil would not hold on to any nutrients and they would wash right through. I would not disagree with what you are saying if a grower has enough clay content to give a decent cation exchange number. I will be interested in your thoughts.

4/4/2019 8:38:26 AM

Wixom MI.

I have high og.of 14.4 soil ph is 7.7 and my manganese is very low at 2 calcium is high at 3853 and boron is high at 1.8

What is the best product for me to use. Is their a good sulfer product to use and if so were can i buy it ? And would epsom salts be good enough or not ? Im bad at the soil game i will post my soil test in my diary under Wixom Grower.

4/4/2019 10:07:37 AM

Grittyville, WA

I dont think Epsom changes ph.

4/4/2019 3:01:55 PM

Team Canuckle Heads

No but the S will. 13% in the Epsom salt.

I messed around with this in the winter. Sent 2 soil tests to A & L Labs. The first was off the shelf mixture mostly OM. The second was the same only I added a bunch of organic ferts. The only S I added was the Epsom salt and the S went from 94 ppm in the first sample to 1634 in the second and the pH went from 7.3 to 6.5

4/4/2019 3:25:40 PM

Team Canuckle Heads

I grew a tomato plant in the second sample, pulled the plant and sent the soil and the plant at the same time. Tissue test looks great.

4/4/2019 3:57:21 PM

On top of Brush Mountain, Pa.

Chris: Here is my suggestion for you:
SOIL PRESCRIPTION
1.    Compost: 1 inch of good compost spread over the surface of the soil. (Compost is more about adding organic matter than nutrients.)
2.    Humic Acid: 1 pound per 100 square feet.
3.    Kelp meal or azomite: 1 pound per 100 square feet. You could use one one year and the other the next.
4.    Fulvic Acid: 1 pound per 100 square feet.
5.    Nitrogen: 1 pound of feather meal and 1 pound of alfalfa meal per 100 square feet.


Agricultural Sulfur: 150 grams per 100 square feet
Soft Phosphorus Rock: 4 pounds per 100 square feet
Potassium Sulfate: 150 grams per 100 square feet
Manganese Sulfate: 300 grams per 100 square feet
Zinc Sulfate: 60 grams per 100 square feet

Conversion factors:
1 pound = 454 grams
1 PPA = 1 gram per 100 square feet

This is per 100 square feet so multiply it by the proper number and it will be for your entire garden. When you are putting it together to put it on, mix it well in a bucket.

What do you think?

4/4/2019 4:49:04 PM

Wixom MI.

Thanks marv very helpful now i have to see if i can find these products.....

4/4/2019 6:56:24 PM

Oak Grove, Mn

I think the ideal OM is dependent on your soil type. If you have a sand base..somewhere in the teens is safe. Mine was about 15% last year..It was the first year I did not struggle with retention of moisture. If you are in clay...to avoid disease, it would be much safer to keep it lower. I am sure there are other variables to consider to pick the right number for your garden.

4/4/2019 8:03:49 PM

Deer Park, WI

Marv- Great point. I acknowledge my suggested range is generally applicable to loamy soil types and may not be the ideal fit for soils at either end of the texture spectrum. I respect your experience regarding high sand/low-no clay soils and how the OM requirement there is far greater than the values I've suggested, thank you for challenging me on that.

Zeke- With all do respect, it is widely published that sulfate (SO4) in both epsom salt as well as gypsum has no impact on pH. I certainly do not question that your soil sulfur levels showed a change, as they should with the addition of sulfur/sulfate based amendments. However, the change in pH you observed was due to factors other than the addition of epsom salt. other organic ferts and/or simple sampling variation are likely sources of the change you saw.

Glenoma- OM is composed of three fractions: the living (15%), the dead (~35%) and the very dead (humus) (50%).

All three stages of OM can be hosts for bad guys: living fraction IS/can be the bad guys, dead fraction is food for bad guys (especially in saturated, low oxygen environments), and very dead (humus) stores the nutrients the bad guys feed on. So you can see what is good for the plant can also be good for the bad guys. Striking balance is key.

4/5/2019 7:15:31 PM

On top of Brush Mountain, Pa.

Thank you Joe. It relieves me that your OM answer fits in with what I thought I knew. Actually with my low clay content soil I was considering adding clay to bring the cation exchange content up even higher than it is though I would really need a lot of clay, more than I want to deal with.

4/5/2019 8:32:12 PM

Pittsburgh, PA

Stop on over Marv. Lots of clay in my patch. Haha

4/5/2019 8:59:44 PM

Central NY

....it’s pretty much science

4/5/2019 9:06:29 PM

Central Illinois

correct me if I am wrong sulfate makes sulfur availible to the palnts but does not change PH ,elemental sulfur is not plant avialible but does change PH

4/6/2019 8:09:59 AM

On top of Brush Mountain, Pa.

Elemental sulfur is converted into sulfuric acid in the soil which lowers the soil pH and then the sulfate portion of the sulfuric acid is used by the plants.

4/6/2019 8:20:44 AM

On top of Brush Mountain, Pa.

Elemental sulfur is converted into sulfuric acid in the soil which lowers the soil pH and then the sulfate portion of the sulfuric acid is used by the plants.

4/6/2019 8:20:57 AM

On top of Brush Mountain, Pa.

Third time is a charm!

4/6/2019 12:07:46 PM

Gone With The Win

Chops!!! I knew you were going to say that...I love it... did you get a microscope to check your tea brews?

4/6/2019 9:15:41 PM

Lymington UK

For me the real problem with adding organic matter is putting it on without testing for nutrients first.
Eg It's so easy to add manure and end up with phosphate levels through the roof.
Believe me Stuart and I have the T shirt and you try getting rid on the phosphate.
Perhaps the question we need to ask is "Are we putting om into our patch because we want to amend our fertility or do we want to improve the structure".
We don't all live on beautiful deep loamy soil.
If you buy a plant from your local supermarket you will find that it is in SUPER FLUFFY compost which is where I feel we need to be going.
We dig our patch next week in our own over the top style and I'll put a short video on instagram to show what we're looking for.
Exciting times ahead Ian

4/7/2019 7:12:39 AM