How to convert empirical P soil data for InVEST NDR


I have some empirical P values for soil matter where P in soil is expressed as µg / g of soil. Is there any methodology to convert these spot values to usable input NDR P-Load values in the biophysical table for the different LULC classes? The only methods I can find currently are for water samples, not soil.
Many thanks,

Can anyone at NatCap help me with this please? Still hoping for some help

Hi @Lisa3,

Thanks for the question, we’ve reached out to see if any of our science leads had thoughts on this. We’ll post back when hear from them!

~ Doug

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Hi @Lisa3 -

Sorry for the long delay. None of us here have made use of the kind of data you’re describing, but our hydrologist suggests not doing it. P in the soil can come from many processes and is not comparable to the P that is available for runoff. For instance, you can have a soil with lots of P fixed in the matrix, but this P is stuck there and won’t go anywhere with precipitation. It probably would be exported if the soil is eroded but this is not considered in the model.

~ Stacie