[Characteristics and source of soil condensation water in Guanzhong Plain, China]

We determined the quantity and source of soil water condensation versus atmospheric vapor condensation in Guanzhong Plain and explored their role in water balance, using three different types of hand-made micro-lysimeters (open-ends, top-seal, and bottom-seal designs). Field monitoring of the vapor condensation process was carried out from late September to late October in 2018 and from March to May in 2019 using the weighing method. Results showed that during the monitoring period, condensation occurred every day without rainfall event. The maximum daily condensation for the open-ends, top-seal and bottom-seal designs were 0.38, 0.27 and 0.16 mm, respectively, indicating that vapor flow in soil pores was the main source of soil water condensation, and that the measurement using the open-ended micro-lysimeter could faithfully reflect the amount of condensation in Guanzhong Plain. During the monitoring period, total soil water condensation reached 14.94 mm, accounting for 12.8% of the precipitation in the same period (116.4 mm), and the ratio of atmospheric vapor condensation to soil vapor condensation was 0.59:1.