can i stick 6ga wire directly in earth instead of using grounding rod?
&quot;Buried wire ground&quot; is possible, but that's a ground ring &quot;not smaller than 2AWG, at least 20 feet long&quot; buried 30 inches or more deep around the building.
If you are building the building, providing a concrete encased electrode (usually an electrical connection to the reinforcing steel) as part of the building footings is inexpensive and very effective.
You can stick your 6Ga wire a couple of feet in the ground and clamp it to a ground rod driven from the bottom of the hole (which makes it more effective) but no, you can't just stick a 6Ga wire in the ground and call it a day. If this is your only grounding conductor, you should extend a trench so that you can drive a second grounding rod a minimum of 6 feet (more is fine) from the first rod (it's far less expensive than doing the measurement with the fancy equipment you won't have to determine if one ground rod is adequate.)
You may also need to protect the grounding wire with conduit where it is &quot;exposed to damage&quot; aboveground.