A subsurface emitter includes a valve both preventing water from draining from the system and blocking the entry of roots and soil into the emitter body. A nozzle is present at one or both ends of a vertical tube. A piston is held in a normally closed position by a spring in the absence of water pressure, covering at least one port in the nozzle. When sufficient water pressure in provided, the spring is compressed and the nozzle uncovers the port providing a subsurface spray of water. The spray of water is sufficient to clear mineral deposits which otherwise may accumulate and block the port.