Can you spot the grid pattern throughout the field? Those are 1”wide by 9” deep sand channels that will aid the soil in absorbing standing water. The sand removes the water from the surface so the top soil won’t get muddy and also holds moisture within the soil so the lawn can absorb water slowly.
Last week, the field was reseeded so new grass will grow and fill in the sand channel grid. It takes about eight weeks for the seeds to germinate, take root and establish itself.