Impact of organic matter amendments on soil and tree water status in a California orchard

•Fall-applied CM led to more complete decomposition and greater C stabilization.•Fall-applied CM significantly increased volumetric water content by 22% in year one.•Fall-applied CM increased soil water retention between 0 to ˜100 kPa by 13%.•The greatest benefit from OMA use may be when irrigation supplies are limited.•OMA use in young orchards could have a long-term impact on orchard productivity.