View the resource guide here: https://online.maryville.edu/blog/soil-conservation/   This guide dives into topics such as:
Working with managers, Rocky Moutain Research Station researchers have evaluated the available treatments for short-term rehabilitation of both smaller, hand-built and larger, machine-built burn piles. For the smaller piles, they found that both soil nitrogen and plant cover recovered to a level similar to that of the surrounding forest within two years, indicating that these scars may not need rehabilitation unless in a sensitive area.

An Oklahoma Cooperative Extension Service publication, this Extension Fact Sheet describes soil reclamation options. 

This Natural Resources Conservation Service Technical Note provides information on: characterization of saline and sodic soils;effect of salinity on plants; management of salinity problems; planting in saline-sodic soils;and species selection for salt affected areas.

This document lists various laboratories in the western United States that perform soil testing.