Water-Repellent Soil Remediation by Surfactant Application Using a Drip-Irrigation System

This dataset contains data collected from field studies of water movement through the soil using electrical resistivity tomography (ERT), laboratory analysis of the soil's chemical properties, and wettability. The field is irrigated with wastewater, leading to the development of soil water repellency. This study investigated the drip application of a nonionic surfactant as a remediation approach to the soil water repellency with 0, 5, and 10 g/L surfactant concentrations.

***Study Objectives***
we investigated the effect of applying a nonionic surfactant to a water-repellent soil surface via a drip-irrigation system on SWR remediation. The efficacy of this treatment method was assessed based on (1) remediation of preferential flow pathways, and (2) spatial homogenization of soil moisture and chemical distribution within the soil profile.

*Instrumentation*
All ERT measurements were carried out using SYSCAL Junior (Iris Instruments, France) multi-electrode resistivity meter. Soil analysis was done in a commercial lab according to standard procedures.

*Data Description*
The data included in this data set has been organized into separate excel sheets according to the figure list below:

Figure 1 - Spatial variation of electrical resistivity over time in treated wastewater (TWW)-irrigated plots.
Figure 2 - Temporal changes in electrical resistivity (ER) measured before, during, and after irrigation in the treated wastewater (TWW)-irrigated plot treated with 0 mL/m2 surfactant #20 (2019).
Figure 3 - Temporal changes in electrical resistivity (ER) measured before, during, and after irrigation in the treated wastewater (TWW)-irrigated plot treated with 5 mL/m2 surfactant #20 (2019).
Figure 4 - Temporal changes in electrical resistivity (ER) measured before, during, and after irrigation in the treated wastewater (TWW)-irrigated plot treated with 10 mL/m2 surfactant #20 (2019).
Figure 5 - Temporal changes in electrical resistivity (ER) measured before, during, and after irrigation in the treated wastewater (TWW)-irrigated plot treated with 0 mL/m2 of surfactant #20 in 2020 and 2021.
Figure 6 - Temporal changes in electrical resistivity (ER) measured before, during, and after irrigation in the treated wastewater (TWW)-irrigated plot treated with 10 mL/m2 surfactant #20 in 2020 and 2021.
Figure 7 - Mean soil water content, saturation degree, soil organic matter (SOM), EC, Cl, N-NO3, Na, P-Olsen, K, Ca+Mg, SAR, and PAR, sampled from 0–20 cm and 20–40 cm.
Figure 8 - Mean values of saturation degree, soil EC, Na, Cl, N-NO3, P-Olsen, K, Ca+Mg, SAR, and PAR, sampled every 25 cm along a line transect from 0–40 cm depth.
Figure 9 - Average water drop penetration time (WDPT) across the soil surface for plots drip-treated and soil samples sprayed with 0, 5 and 10 (mL/L) surfactant #20.
Figure S1 - Temporal changes in electrical resistivity (ER) measured in 5 mL/m2 surfactant #20 in 2020 and 2021.
Figure S2 - Mean values according to treatment plots.