Electrical resistivity imaging for monitoring soil water motion patterns under different drip irrigation scenarios

Daniela Vanella,Juan Miguel Ramírez-Cuesta,Giuseppe Longo-Minnolo,Simona Consoli,Alessandro Sacco,Giuseppe Luigi Cirelli

doi:10.1007/s00271-020-00699-8

Daniela Vanella, Juan Miguel Ramírez-Cuesta + Show 4 more

Open Access

https://doi.org/10.1007/s00271-020-00699-8

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Abstract

The use of hydrogeophysical methods provides insights for supporting optimal irrigation design and management. In the present study, the electrical resistivity imaging (ERI) was applied for monitoring the soil water motion patterns resulting from the adoption of water deficit scenarios in a micro-irrigated orange orchard (Eastern Sicily, Italy). The relationship of ERI with independent ancillary data of soil water content (SWC), plant transpiration (T) and in situ measurements of hydraulic conductivity at saturation (Ks, i.e., using the falling head method, FH) was evaluated. The soil water motion patterns and the maximum wet depths in the soil profile identified by ERI were quite dependent on SWC (R2 = 0.79 and 0.82, respectively). Moreover, ERI was able to detect T in the severe deficit irrigation treatment (electrical resistivity increases of about 20%), whereas this phenomenon was masked at higher SWC conditions. Ks rates derived from ERI and FH approaches revealed different patterns and magnitudes among the irrigation treatments, as consequence of their different measurement scales and the methodological specificity. Finally, ERI has been proved suitable for identifying the soil wetting/drying patterns and the geometrical characteristics of wet bulbs, which represent some of the most influential variables for the optimal design and management of micro-irrigation systems.

Highlights

In semi-arid and arid regions, irrigation management practices depend on the accurate characterization of temporal and spatial soil water content (SWC) dynamics (Vereecken et al 2008)
Following the homogeneous structure of the soil and the climatic conditions at the field site (Fig. 3), it was shown that the driving factor explaining the decreasing trend in electrical resistivity (ER) is closely related to SWC changes induced by drip irrigation
electrical resistivity imaging (ERI) technique has allowed to evaluate the efficiency of the microirrigation through the simultaneous monitoring of the flow supplied by the different drippers, enabling the identification of potential failures in the irrigation system

Summary

Introduction

In semi-arid and arid regions, irrigation management practices depend on the accurate characterization of temporal and spatial soil water content (SWC) dynamics (Vereecken et al 2008). The main drawback of these SWC methods concerns their pointbased nature and the non-representativeness and restricted sampling volume (i.e., 10–100 c m3) These measurements strongly depend on sensors location in the soil profile (e.g., Bogena et al 2015; Robinson et al 2008). Mean ER values (Ω m) showed a decreasing trend of about 16% at all the treatments from the beginning (June) to the end (September) of the 2019 irrigation season (Fig. 5a–d). This ER decreasing pattern was higher in T1 (Fig. 5a) and T2 (Fig. 5b) (19% and 20%, respectively) and lower in T3 (Fig. 5c) and T4 (Fig. 5d) (10% and 14%, respectively)

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