Drip irrigation increases tomato yields in salt-affected soil of San Joaquin Valley

This study evaluated the potential for subsurface drip irrigation in processing tomato to reduce subsurface drainage, control soil salinity and increase farm profits in areas affected by saline, shallow groundwater. Subsurface drip irrigation systems were installed in three fields of fine-textured, salt-affected soil along the West Side of the San Joaquin Valley. No subsurface drainage systems were installed in these fields. Yield and quality of processing tomato were compared with sprinkler irrigation systems. Yields increased 5.4 tons per acre to 10.1 tons per acre in the drip systems with similar amounts of applied water. The solids content of drip-irrigated processing tomato was acceptable. Water-table levels showed that properly managed drip systems could reduce percolation below the root zone, reducing subsurface drainage. Yields of the drip systems were also similar over a range of soil salinity levels.