Effects of organic mulching and regulated deficit irrigation on crop water status, soil and yield features in an orange orchard under Mediterranean climate

The adoption of soil and water conservation measures (SWCM) is essential for improving the use of natural resources and making the agro-systems more resilient to climate change. In this context, a three-years trial was carried-out in an orange orchard characterized by different soil management (SM, i.e., bare and organic mulched soils) and water regimes (WR, i.e., full irrigation, FI, and regulated deficit irrigation, RDI). In response to the applied SWCM, crop water status (CWS), soil and yield main features were explored using multiple soil-plant-atmosphere continuum (SPAC) monitoring approaches. Overall average water saving of 24 % was achieved under RDI in comparison to FI. The stem water potential revealed a year-dependent behaviour in accordance to the patterns of the main ancillary physiological indicators. The adoption of additional plant-based measurements provided continuous information on the CWS, both in terms of trunk water potential (TWP) and sap flow fluxes, resulting in higher absolute values of TWP (-0.93 ± 0.01 MPa versus -0.83 ± 0.00 MPa) and lower transpiration rates (0.64 ± 0.00 mm d