Abstract
Abstract: Long-term soil salt accumulation could lead to salinization.
Aimed to prevent soil salinization, we investigated soil salt dynamics,
its interface with the groundwater table, rainfalls duration and the
impact periods when salt is mostly accumulated. Total soil salt
accumulation and dynamic distribution were monitored in the 0–80 cm
layer in alluvial farmland from 2018 to 2020. We found soil salt
contents increased by 0.15 g kg–1 and 0.07 g kg–1 in the 0–40 and
40–80 cm soil layers, respectively, which indicated that soil
salinization occurred. We defined the rainstorm impact period (RIP) as
period when soil salt dynamic distribution was affected by rainstorm
event. The salinity time-trend during RIP was sequentially characterized
by a first salt leaching, followed by a rapid and then slow salt
accumulation, which took the first 4 days, from day 4 to 10, and then
beyond, respectively. In the first leaching stage, salt migration
content was determined by rainfall (P < 0.05) which could
leach 41.5% of salt on average in the whole soil layer. In the rapid
accumulation stage, lots of salt accumulated due to high
evapotranspiration and shallow groundwater table. In the slow
accumulation stage, salt accumulation rate was inhibited by deeper
groundwater table. In addition, the total accumulated soil salt in the
whole soil layer increased by 0.14 g kg–1 in the RIPs, which comprised
only 14.5% of the overall study period, but the value accounted for
63.6% of the salt accumulation, thereby indicating that RIPs were the
main periods when salt accumulated during the soil salinization process.
Our results provided insights into soil salt dynamic distribution during
RIPs, thereby facilitating the effective prevention and control of soil
salinization.