Effect on Soil Hydrodynamic Parameters in Fields Mulched with Gravel for Different Periods of Time

Abstract

Soil-water characteristic curve (SWCC) and soil hydraulic conductivity are important soil hydrodynamic parameters, which are of great significance in production practice. In 128 soil samples collected from 0-20, 20-40 cm layers at sampling scales of 32×32 m, the authors determined the effect of different periods of time on SWCC and soil hydraulic conductivity in fields mulched gravel. The water holding capacity of soil changes dramatically throughout time, with NEW having the maximum water holding capacity. As the planting time increases, the soil water holding capacity decreases. Both van Genuchten (VG) and Gardner models can fit SWCC in different time periods well, but the fitting accuracy of the VG model is higher. Geostatistics and Kriging interpolation are used to study the spatial variability of the VG model parameters of the SWCCs. The parameters θs, α, and n show a strong spatial correlation as a whole and are slightly affected by random factors. The changing trend of soil unsaturated hydraulic conductivity (K(θ)) in gravel-mulched fields is faster than the CHECK, and the NEW has the fastest change trend. The data suggest that fields mulched with gravel retain more water, with the NEW having the most noticeable water retention effect. The study’s findings can be used to investigate the regional variations in soil hydrodynamic characteristics in gravel mulched fields in arid locations.