Subsoil Moisture

I had a septic tank evaluation to do yesterday.  The significance is that I need to bore 3 holes 5 feet deep.  In addition to the evaluation for filter field suitability,i9t gives me a chance to evaluate subsoill moisture.  Trees are very efficient at taking water out of the soil.  All my borings were near trees.  I was still finding moisture below 6 inches.  Does this mean that cropland has decent subsoil moisture.  I would say yes.  I would also say that the heat will still stress the crop, but early corn should be in shape to make a decent crop.  The jury is still out on corn planted after May 1 in our area.