Okay, here's what I think you could do (but I'm no expert either):
Decrease resolution to 0.5 for the "Resolution Per Unit" value in the "Lagoa Emit Grid"
Disconnect the "Resolution to Substeps" from the "Lagoa Simulate Multiphysics"
(unsure about this, but I like to control it "by hand")
Set "Resolution to Substeps" to 2
And for something more dirt-looking: lose the sphere-shape. At least plugin an instance shape into your "Lagoa Emit Grid", preferably with a small group of slightly irregular objects, or at least with something like an "Icosahedron". The look of the sphere obviously does not "cut it", especially if your "Resolution Per Unit" is so high to begin with...