Irrigation scheduling using continuously monitored data of soil volumetric water content

Multiple depth capacitance sensors, capable for continuous measurements of soil water content at different depths, were used for on-farm comparative evaluation of two different irrigation scheduling methodologies: a) ‘gaiasense’, a commercial available new irrigation tool which has been recently developed and b) ‘control’ irrigation which is the irrigation strategy empirically used by farmers. Comparison of the two irrigation methodologies was performed in grapevine and cotton plants using both soil water content data as well as measurements of plants’ hydrodynamic (leaf water potential) and physiological parameters (gas exchange) during successive irrigation cycles. Indices derived from soil water content measurements and plants’ physiological parameters were estimated for the assessment of each irrigation methodology performance. In particular, irrigation efficiency (%) and water stress integral (Sψ) calculated from soil water content and predawn water potential measurements respectively were used. Results indicated that ‘gaiasense’ protocol maintains higher values of stomatal conductance throughout the experimental period in both crops compared to control irrigation. Water stress integral (Sψ) in control plants exhibited significantly higher values in both crops examined. In addition, irrigation efficiency index was significantly higher in ‘gaiasense’ treatment (89.3 and 86.4% for cotton and grapevines respectively) compared to the control (75.2 and 73.1%). These results indicate that ‘gaiasense’ protocol could be effective for optimization of irrigation management in these crops.