Conclusions
The dynamics
of soil
water movement and recharge to groundwater were studied in the Yellow
River irrigation area during the maize growing season by combined
physical and isotopic techniques. The results indicate
that the soil at 0-50 depth was
mainly influenced by precipitation infiltration and evaporation. The
entire profile of soil was affected by rapid infiltration from
irrigation while the soil water mainly moved downward in the mode of
piston flow. The maize root system had reached the depth of 100cm during
the tasseling periods according to SWPs decrease from 70 to 100cm. The
infiltration and capillary rise were totally 544.6 mm in 2020, which
were similar with that in 2019. However, the total deep
percolation(156.6mm) was smaller than that in 2019 due to the higher ET.
It can be concluded that the leakage of ditch was the major recharge
resource of groundwater for the fast water table rise.
The observed temporal variations of soil water in multiple soil layers
in two different land covers contribute toward the understanding of the
mechanism of soil water and recharge to groundwater in the irrigation
area of arid and semi-arid climates. The results provided critical
information for soil and water management to improve irrigation
efficiency and water use efficiency.