i can see where, your thought pattern is going,
me personally, i'd like to get a front end loader in there, and remove all the grass, [ a backhoe would work perfect,,, remove the grass, and using the bucket you could bust your ground with it, ]
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i just dont see a lawn mower / harrow attachment doing that plot any good, it looks like some '' TOUGH'' grass,
use yo0ur redneck ingenouity,,,,,,,i got confidence, that you will do what it takes to make this mission happen<