Location: Watershed Management ResearchTitle: Modeling the effect of antecedent soil water storage on water and heat status in seasonally freezing and thawing agricultural soils) Author
Submitted to: Geoderma
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/16/2013
Publication Date: 5/25/2013
Citation: Li, R., Flerchinger, G.N., Shi, H., Fu, X., Li, Z. 2013. Modeling the effect of antecedent soil water storage on water and heat status in seasonally freezing and thawing agricultural soils. Geoderma. 206:70-74. Interpretive Summary: Irrigation during the autumn is a widespread practice to leach salinity from the soil and to store water in the soil profile for the following spring growing season. However, the efficiency of this practice for overwinter water storage can be a concern. The influence of autumn soil water content on soil water storage was simulated using the Simultaneous Heat and Water (SHAW) Model. Initially dry soil profiles increased their water storage over the winter, but were not effective at leaching salinity; wet soil profiles may effectively leach salinity, but they lost water over the winter season due to evaporation and percolation. These results are useful to determine proper autumn irrigation schemes to reduce salinity and efficiently store soil water over the winter season.
Technical Abstract: Taking Hetao Irrigation District of Inner Mongolia's agricultural production as a background and based on field observation data and field measured meteorological data, the influence of antecedent soil water storage (ASWS) on water and heat conditions was simulated and analyzed using the SHAW model during the seasonal freezing-thawing period. The results showed that the amount of ASWS prior to soil freezing can influence the depth of freezing and penetration of cold temperatures. When ASWS within the surface 1m is less than or equal to 150mm, soil water storage (SWS) was always increasing over the winter period. However, for ASWS greater than 150mm, SWS went through 3 phases, that was decline-increase-decline. During soil freezing, the amount of upward moisture transfer made up the deficit caused by evaporation and percolation for ASWS of less than or equal to 150mm. Conversely, the amount of percolation was greater than that of upward transfer for ASWS of greater 150mm. During soil thawing, moisture continued to transfer from lower soil layers to upper layers and overtook evaporation and percolation for ASWS less than or equal to 210mm. However, the amount of evaporation and percolation was greater than the upward transfer for ASWS of greater 210mm. These results are useful to determine proper irrigation scheme in autumn and can also be used in future research on reducing soil secondary salinization.