Effects of Drilling Fluids on Soils and Plants: II. Complete Drilling Fluid Mixtures

Six typical drilling fluids (muds) and a drilling fluid base were mixed with six soils at ratios of 1:1 and 1:4 volumes of liquid mud/soil; these mixtures were tested for their effects on plant growth. Green beans ( Phaseolus vulgaris ) and sweet corn [ Zea mays var. succharata (Sturtev.) Bailey] in pots in the greenhouse grew normally in a few mixtures, but in most instances plants had reduced growth when compared to those growing in soil alone (controls). It was concluded that high levels of soluble salts or the high exchangeable sodium percentages were the primary causes of reduced plant growth. The high salt content in some fluids was mostly from added potassium chloride, sodium hydroxide, and sodium dichromate. Dispersion of mud‐treated soils caused by high exchangeable sodium percentages occurred in these samples because of the sodium hydroxide and sodium dichromate added to typical muds.