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minnesota

The post By Tremor on "percent organic material" was very interesting, but I am confused as to what constitutes OM. I have been composting in my patch for 3 yrs(raised the level about 16 inches}thinking I have been adding tons of OM, evidently I was wrong. If compost and manure are not pure OM what else are they? Does anyone know what percent OM pure manure is? how about pure compost? What soil ammendment would have the highest percentage of OM? I think this pumpkin growing stuff might be over my head.

11/16/2002 6:27:45 PM

Kentucky - USA

hehe..it's over my head too smallpatch..

Anybody care fill us in on this?

Thanks..

11/16/2002 6:51:10 PM

Deer Park WA

Add Leaves/manure/cover crops, whatever, the idea behind OM is to make a wide variety of nutrients readily avalable to the plant at the cation exchange level. Many factors play into this like soil type, friability, soil compaction, basically I have never in 30 plus years of gardening seen too much organic matterial in any garden, it just melts away to fast...

11/16/2002 8:17:02 PM

Ctpumpkin@optonline.net

Check out this website for the best easily understandable definition I was able to find.

http://www.noble.org/ag/Soils/OrganicMatter/Index.htm

Simply stated. We add organic material to soils to improve their nutrient holding capacity, moisture rentention capability, add space for oxygen to reside in, and reduce compactablility. The organic material we add can be leaves or grass clippings & other yard wastes. Compost from municipalites or our own yard recycling can even include degradable organic table scraps. Animal manures of various forms are also very good because they run higher in elemental plant nutrients.
In time, organic "material" is eventually converted by microorganisms & oxydation into "stable organic matter". It takes a lot of organic material to become a little organic matter.
I think a lot of the confusion centers around the "Percent Organic Matter" (%OM) that we see on soil test results. It is listed on the printed results by WEIGHT. Yet I have seen other "Giant Pumpkin" websites that suggest tilling 4 inches of organic material into the top 12 inches of soil to end up at a 25% organic material content. That is completey wrong. The end result would be a 20% (short term/before compaction) increase in VOLUME. But only the volume of organic material. In the first season, only a small amount of the added material will be converted into matter. And remember, matter is tested for by weight.

I THINK this is where the confusion comes from. Does the explaination help? Or did I just make things even worse?

Steve

11/16/2002 9:29:57 PM

Cornwall UK.(50N 5W)300ft.

Small patch
The organic matter % of soil is calculated by weighing a sample of dried soil burning it and then weighing the ash.
The difference in the 2 weights is turned into a %.

11/17/2002 1:50:23 AM

Caceres, Spain

Smallpatch did you get it? You have now a lot of good information. I only want to add one think to clear any darkness:
WATER + ORGANIC MATTER + ASHES
that's all you can find in any manure, compost, amendment. Many packets don't reffers on the water content, because it varies a lot, but if you find in a compost 20% OM, don't think that the remainders 80% are ashes (inorganic)
I would dare to affirm the highest percentage is in peat, but...

11/17/2002 2:29:04 AM

Connecticut

small patch I checked out the web page that tremor recomended and it explained it in easy to understand manner

11/17/2002 9:56:32 AM

minnesota

Thanks for the feedback. I have an awful lot still to learn.

11/17/2002 2:51:32 PM