[USCC] compost and road salt

[Chaney, Rufus]

Kathy Powell et al.:

A more direct answer about compost and road salt is that increased soil
organic matter reduces the toxicity of soluble salts in soils. It does
this by increasing the amount of water retained by the soil, so the
concentration of salt in the soil water is lower than for soils with
lower soil organic matter.

At the same time, some composts are relatively high in salts and can
cause salt accumulation in dryland agriculture without irrigation.
Manure composts and biosolids composts are high in soluble salts. High
cumulative applications over time without rainfall or irrigation
leaching can eventually cause salinity. Some manure can also cause SAR
risk from the high K and Na present in the manure or manure compost.
That is rare and only reported for experiments with massive single rates
of application.

So, in general, if soils have received composts or other organic matter
resources and developed increased stable soil organic matter, road salt
and other salt is a lower risk than for the same soil without increased
OM.

Another reason compost is favorable for soil quality.

Rufus Chaney
Beltsville, MD

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Kathy Powell <Powellk at co.portage.wi.us> wrote:
  To the USCC List Serve

Is anyone familiar with how rad salt affects compost used in erosion 
control (berms, socks or blankets)t?

Is it possible for salt laden water running through berms or filter
socks 
to be captured in the cation exchange process or does it flow on
through?

Any protection for plants from salt damage as a result of using compost?

Kathy Powell