soil testing:

pH level:
site one - 6.99
site two - 7.09
site three - 6.59
site four - 6.62

presence of salt:
site one - 2 drops - high
site two - 4 drops - medium
site three - 2 drops - high
site four - 1 drop - high

moisture content:
site one - 15%
site two - 28%
site three - 19%
site four - 11%

parent material:
site one - sandstone
site two - sandstone
site three - sandstone
site four - sandstone