When cultivating a selected field crop (alfalfa), we aimed to examine its positive effects on the variability of soil infiltration capacity. A total of 21 monitoring points were proposed for investigating soil hydraulic conductivity on the targeted plot with a total area of 47.64 ha, divided between the irrigated and non-irrigated areas. The plot is located outside the village of Oponice (Slovak Republic) and is managed by VPP Kolíňany. The study of hydraulic conductivity has been ongoing on the selected plot for several years. The presented results come from a two-year experiment, during which work operations related to the cultivation of alfalfa were carried out on the plot. The unsaturated hydraulic conductivity of the soil was assessed several times a year using a Mini Disk Infiltrometer, while soil moisture at monitoring points and the dependence of the measurement date (work operations, weather conditions) were also monitored. The average soil moisture content in the pilot measurements reached 18.77% vol. (CV = 1.44%), in the secondary measurements 17.21% vol. (CV 20.49%), in tertiary measurements 15.27% vol. (CV = 10.38%), and in the last measurements 15.26% vol. (CV = 10%), which ultimately represents a positive result of soil moisture balance. To test the significance of the differences between measurements taken across the entire surveyed plot, a one-factor ANOVA analysis was used to compare the measurement dates. The results showed a statistically significant difference when examining the effect of the time period of soil infiltration capacity monitoring between all measurements (p = 0.004). The mutual combinations of individual measurement dates were mostly significant (p = 0.03 for IDM1, IDM2; p = 0.003 for IDM2, IDM3), except for one case without a significant difference (IDM3, IDM4; p = 0.52). The second hypothesis was confirmed only at some monitoring points, and it can be stated that the irrigated area had a more significant effect on the soil infiltration capacity. The results obtained by the Shapiro–Wilk test and Welch’s test in irrigated and non-irrigated areas at individual dates showed statistically insignificant differences in three cases (IDM1, p = 0.123; IDM3, p = 0.382; IDM4, p = 0.445) and statistically significant in one case (IDM2, p = 0.0175). Based on the hypotheses and the results obtained, it can be said that the work tasks performed have a decisive influence on the infiltration capacity of the soil. The phenomenon of “water resistance” did not manifest itself in our research on soil infiltration capacity. The results were also evaluated using ArcGIS software 10.0 to display the spatial variability of soil hydraulic conductivity. The last application used to evaluate the results was Orange software 3.40.0, using clustering maps and hierarchical clustering. The results also pointed to variability depending on the dates of monitoring.
Tkáč et al. (Thu,) studied this question.