I have shown that: (1) Sodic soils, sodic materials, or mixtures of soil
and sodic materials having high SAR values that are detrimental to soil
performance and which may also exceed published regulatory threshold
levels can, by means of treatment with chelating agents that cause
release of calcium and magnesium, be ameliorated so that SAR values fall
to non-detrimental levels, without at the same time causing unsuitable
increase in salinity (EC). (2) Permeability of sodic soil markedly
improved after treatment with chelating agents. (3) Using the synthetic
chelating agent EDTA, the low SAR values of treated sodic materials were
persistent. (4) EDTA added to sodic, alkaline drilling cuttings did not
decompose during a test using conditions simulating actual drilling. (5)
Sodic soil treated with EDTA was non-toxic in the Microtox.TM. bioassay.