Re: yet more on composting - to be or not to be

Dick:  thanks for your usual insightful response.

I had heard about dung beetles etc. from Australia and the southern 
US, and I very clearly recall an undergrad field trip (this is from 
several centuries ago when I **was** an undergrad) at UC Davis to a 
tomato processing plant that was irrigating their wastewater onto a 
nearby hayfield which had been "seeded" with specific microbes to 
break down and clean up the water sufficiently for it to drain into 
municipal tiles.  The notion that the soil can and should be managed 
to accept/process/cycle the "returns" from human ingestion is valid 
and appropriate.

What I am not clear on is how doing this in situ, in the field, is 
more advantageous than doing it in a compost windrow on an organic 
dairy or beef farm.  I am trying to recall a study reported by 
Herbert Koepf (biodynamic, German, most recently with the Michael 
Fields Institute) when he came up and spoke here several years ago.  
If recollection serves, the study involved the same quantity of 
manure, land applied in two ways - one as raw manure and the other 
after composting.  Composting lost about half of the C and N, I 
think, prior to land application, which is typical.  I don't recall 
for how many years this was done.  But the take home message was the 
the soil was "healthier" - in various measured parameters - when the 
manure had been applied composted rather than raw.  I think this 
included soil OM, but can't remember what all else, or when it was 

    Koepf's composted manure had, I think, been treated with a 
biodynamic preparation as well.  I recall another most amazing study, 
Swedish I think, that tested the effect of the biodynamic preparation 
on composting and soil quality thereafter.  It was an old paper, and 
unreplicated I think, but surprisingly to me, the biodynamic 
preparation did something distinctly different than other treatments. 
It was a soil study, and involved detailed measurements at multiple 
locations within unreplicated plots.  

    The upshot is that composting ahead of time - whether due to the 
composting itself or the BD prep in some way - enhanced the soil 
improving properties of livestock manure.  As noted by one respondant 
in this dialogue, this is an area that would seem to need research, 
because as you originally noted, there are many logistical and 
economic reasons to compost material **before** hauling it out to the 
field.  It would be worthwhile to determine if the in-situ benefits 
outweigh the pre-application benefits.  Ann

Dr. E. Ann Clark
Associate Professor
Crop Science
University of Guelph
Guelph, ON  N1G 2W1
Phone:  519-824-4120 Ext. 2508
FAX:  519 763-8933