The Innovation Team of Soil Health Care of the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) , published a research paper entitled "Response of soil moisture to prewinter conditions and rainfall events at different distances to gully banks in the Mollisol region of China" in Earth Surface Processes and Landforms.

The Mollisol region is crucial for China's food security, yet active gully erosion has led to increasing arable land fragmentation. Soil moisture patterns are crucial factors in gully bank erosion and may significantly vary depending on the water conditions before winter freezing. Rainfall events can evoke different moisture responses throughout the soil profile of gullies. However, the relative importance of prewinter conditions and rainfall events to the soil moisture responses of gully banks in seasonally frozen regions remains unclear.

This study involved a field infiltration experiment of a gully bank with four prewinter soil moisture regimes and three replicates. We aimed to elucidate the temporal variations in moisture responses under different prewinter water treatments at various distances to the gully bank after three representative rainfall events in the following year. The results revealed that under wetter prewinter conditions, the mid-layer (30-50 cm) exhibited the greatest moisture response amplitude, while under drier prewinter conditions, the surface layer (0-30 cm) showed a larger response amplitude. The study quantified the contribution rates, with rainfall contributing 46%, soil depth contributing 10%, and prewinter conditions contributing 7%. The moisture response amplitude increased with increasing rainfall, and prewinter moisture contribution still dominated (18%) at the end of the rainy season.

This study increases the understanding of the heterogeneity in soil moisture responses and the relationship to rainfall events under different prewinter conditions on gully banks in the Mollisol region. Understanding subsurface hydrological processes and identifying the relative importance of prewinter conditions and rainfall are beneficial for building gully bank erosion models for seasonally frozen regions.

Assistant Researcher Wen Yanru and master's candidate Liu Bao contributed equally to this manuscript, Researcher Wu Wenbin and Associate Researcher Song Qian are co-corresponding authors. This achievement was supported by the National Key R&D Program series projects (2023YFD1501300, 2021YFD1500700, 2019YFA0607401).

Citation and Original Link:

Wen, Y., Liu, B., Yu, Q., Xu, Y., Lin, L., Zhang, B. et al. (2024) Response of soil moisture to prewinter conditions and rainfall events at different distances to gully banks in the Mollisol region of China. Earth Surface Processes and Landforms, 1–11.

Paper Link: https://doi.org/10.1002/esp.5803