Guo et al. (2026) Modeling Soil Salinity Dynamics in Paddy Fields Under Long-Term Return Flow Irrigation in the Yinbei Irrigation District

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Agriculture
• Year: 2026
• Date: 2026-01-15
• Authors: Hangyu Guo, Chao Shi, Alimu Abulaiti, Hongde Wang, Xiaoqin Sun
• DOI: 10.3390/agriculture16020222

Research Groups

Not explicitly stated in the provided text. The study was conducted in the Yinbei Irrigation District, Ningxia, northwest China.

Short Summary

This study evaluated the feasibility of using return flow for irrigation in the Yinbei Irrigation District, Ningxia, by analyzing water quality and simulating long-term soil salinity dynamics, finding that moderate return flow irrigation does not lead to soil salinity accumulation in the plough layer over 20 years.

Objective

• To evaluate the feasibility of using return flow for irrigation in the Yinbei Irrigation District, Ningxia, based on water quality analysis.
• To predict the long-term dynamics of soil salinity (over 20 years) under moderate return flow irrigation using field monitoring and model simulations.

Study Configuration

• Spatial Scale: Yinbei Irrigation District, Ningxia, northwest China; soil profile (0–100 cm), plough layer (0–40 cm).
• Temporal Scale: Two years of continuous field monitoring; 20-year prediction for long-term simulations.

Methodology and Data

• Models used: HYDRUS model.
• Data sources: Water samples collected from main and branch drainage ditches; two years of continuous field monitoring data.

Main Results

• The total salinity of the main return ditches consistently remained below the agricultural irrigation water quality standard of 2000 mg/L.
• Na$^+$ and SO$_4^{2-}$ were identified as the predominant ions in the return flow.
• Seasonal variations in return flow salinity were notable, with higher levels observed in spring compared to summer.
• Soil salinity displayed regular seasonal fluctuations: strong leaching during the rice-growing season kept salinity low in the plough layer (0–40 cm), while evaporation in autumn and winter led to increased surface soil salinity, creating annual peaks.
• Long-term simulations (20 years) showed that soil salinity throughout the entire profile (0–100 cm) followed a pattern of “slight increase—gradual decrease—dynamic stability.”
• Specifically, winter salinity peaks slightly increased during the first two years but then gradually declined, stabilizing after approximately 15 years.
• Long-term return-flow irrigation does not result in the accumulation of soil salinity in the plough layer (0–40 cm).

Contributions

• Provides a scientific basis for the utilization of unconventional water resources (return flow) in arid and semi-arid regions.
• Offers a comprehensive evaluation of return flow water quality for irrigation purposes.
• Presents long-term predictions of soil salinity dynamics under return flow irrigation, addressing concerns about soil degradation.
• Demonstrates that, under moderate conditions, long-term return flow irrigation can be sustainable without leading to soil salinity accumulation in the critical plough layer.

Funding

Not explicitly stated in the provided text.

Citation

@article{Guo2026Modeling,
  author = {Guo, Hangyu and Shi, Chao and Abulaiti, Alimu and Wang, Hongde and Sun, Xiaoqin},
  title = {Modeling Soil Salinity Dynamics in Paddy Fields Under Long-Term Return Flow Irrigation in the Yinbei Irrigation District},
  journal = {Agriculture},
  year = {2026},
  doi = {10.3390/agriculture16020222},
  url = {https://doi.org/10.3390/agriculture16020222}
}