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Compost tea and SOM content

Grasssales2001

LawnSite Member
Location
Shreveport,LA
Does anyone have any research on the long term effects of compost tea on SOM content? Will an increase in microbial populations withouth the addition of some form of organic matter lead to a decrease in SOM content?
 

ICT Bill

LawnSite Platinum Member
Location
Howard County MD
Does anyone have any research on the long term effects of compost tea on SOM content? Will an increase in microbial populations withouth the addition of some form of organic matter lead to a decrease in SOM content?
Send me an email and I can share some data with you, it is soil food web testing done by a national lawn care franchise. It is not public information so I am unable to share it here. The stuff I have is testing on turf on 9 different lawns in 9 regionally different areas

This is not peer review stuff but testing data

bill@ictorganics.com

It definately increases, that is because of root mass increases and active organic matter goes up
 

terrapro

LawnSite Bronze Member
Location
mid-mich
Send me an email and I can share some data with you, it is soil food web testing done by a national lawn care franchise. It is not public information so I am unable to share it here. The stuff I have is testing on turf on 9 different lawns in 9 regionally different areas

This is not peer review stuff but testing data

bill@ictorganics.com

It definately increases, that is because of root mass increases and active organic matter goes up
Bill is there any way I could get that info also? Thanks.
 

Kiril

LawnSite Fanatic
Location
District 9 CA
It definately increases, that is because of root mass increases and active organic matter goes up
This may be true with regard to root biomass, and perhaps even organic matter active fraction, as it applies to root exudates and root mortality, assuming an increase in rooting density/depth. The question is, is it statistically significant? What is it being compared to? How is it being measured (root biomass and organic matter active fraction)? Is this a result of the nutrients contained in the CT, or is it a result of increased microbial nutrient turnover? These are a few important questions the need to be addressed.

Mass balance dictates that unless there is C input equivalent to (or greater than) that which is lost (through a variety of mechanisms), then the net result will be a reduction in SOC/SOM.

@OP

I personally have not seen any journal publications that address CT and its impact on soils (i.e. as a soil drench or applied on turf). I have seen several trials that do measure some soil and turf characteristics (variable and conflicting results), however the published research I have seen on CT is predominately focused on foliar disease control, not on use as a soil drench.
 

ICT Bill

LawnSite Platinum Member
Location
Howard County MD
This may be true with regard to root biomass, and perhaps even organic matter active fraction, as it applies to root exudates and root mortality, assuming an increase in rooting density/depth. The question is, is it statistically significant? What is it being compared to? How is it being measured (root biomass and organic matter active fraction)? Is this a result of the nutrients contained in the CT, or is it a result of increased microbial nutrient turnover? These are a few important questions the need to be addressed.
You make a good point, and yes it does need more detail, the testing data is a typical soil test just giving a percentage reading of SOM, I can make some guesses but that is all that they are

I personally have not seen any journal publications that address CT and its impact on soils (i.e. as a soil drench or applied on turf). I have seen several trials that do measure some soil and turf characteristics (variable and conflicting results), however the published research I have seen on CT is predominately focused on foliar disease control, not on use as a soil drench.
AACT (in Ag) is typically sprayed as a foliar for disease supression not used as a soil amendment, most large scale compost tea users either make a ferment of fish, kelp, humate, with other foods based on the type of plant or soil needs or use extracted compost, it scales easier than brewing and has some organic matter content rather than AACT that has very little
 
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