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[compost_tea] Re: high active bacteria, low total bacteria, low active and total fungi - possible reasons?



Chris-with my amateurish amount of experience working with
mycorrhizae 
in ornamental nursery plants, I'd say a good bit of the problem might 
be a history of "inorganic" fertilizer application.

Mycos are very sensitive to free phosphate (which is apparently very 
rare in soil under "natural" conditions).  Myco innoculant 
manufacturers all recommend using NPK ferts with a low middle number, 
always under 10, or applying reduced rates.  With both high nitrate 
and phosphate levels in the soil test, I wonder if any myco has 
persisted on the roots of your roses.  As an aside, I doubt that the 
SFI active/total fungi numbers reflect myco, altho they point to a
non 
fungi-friendly soil. I believe a separate root analysis is needed to 
determine how much colonization  of myco is there.

With high levels of nutrients in your soil, I imagine that adding 
organic matter will be all that's needed in the future...my 2 cents! 

Glen 

--- In compost_tea@yahoogroups.com, chris reid <reidchris@e...> wrote:
> On a recent soil test, the results showed a mid-range total 
bacterial
> biomass, and of that high active bacterial biomass (137.7, where a 
range of
> 5-15 is desired range).  Total fungal biomass is low (139, with 
desired
> range 200 - 300), and active fungal biomass is at 16 of 139.
> 
> Does anybody have suggested causes of this big difference?  Soil 
tests show
> 5.1 pH, high available nitrate nitrogen, low available ammonium, 
high to
> very high phosphorus, very high potassium, very high calcium,
medium 
high
> magnesium.  "Crop" is hybrid tea roses (formal rose garden).  It is 
next to
> a lawn and a boxwood hedge, but the area is level and based on the 
pH, I
> don't think the roses are getting lawn runoff (especially since 
they've been
> liming the lawns indiscriminately for years...).
> 
> PHC on their website has a chart of the effect of various
fungicides 
on
> mycorrhizae.  I'm told that the two most common ones used on roses 
would be
> Maneb and Mancozeb. They are not supposed to do much harm to the
> mycorrhizae.
> 
> So, the scenarios that occur to me are:  excess triple super 
phosphate used



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