Right now, on very small blocks of his vineyards, which ride the ridge between Half Moon Bay and Woodside, underground probes are monitoring water absorption rates and radioing that information to a central computer, which then relays it to irrigation valves powered by thumbnail-size solar panels. “In a typical vineyard, you can find plants that are dying for water and undercropping, and you can find plants that are waterlogged and producing poor-quality fruit,” said Rodgers. The resulting technology — which Rodgers is starting to sell through his startup company WaterBit Inc.