Spatial variability of soil water conductivity in root-zone of cotton filed under single and double-tube modes under mulched drip irrigation with brackish water
Soil water conductivity can directly characterize soluble salt status. To analyze the spatial distribution of soil salinity in cotton root zone under single-tube and double-tube modes under mulched drip irrigation with brackish water, WET probes were used to measure the soil water conductivity of selected soil profile from 0 to 60 cm in this study. The spatial distribution and variability of soil conductivity were evaluated by statistical eigenvalue analysis, semi-variance function construction and Kriging interpolation. The results showed that soil water conductivity varied moderately and the optimal semi-variance function fitting models were Gauss models under two drip irrigation modes. The spatial variation of the single-tube mode was more affected by structural factors than the double-tube mode. The salt accumulation was higher in the double-tube mode for the loam soil, which reached the significance level (P<0.05), and the single-tube mode was more capable of transversing seepage expansion. The results can provide some guidance for optimizing brackish water irrigation.