Hu et al. (2026) Multi-depth actively heated fiber optics sensing quantifies spatial-support uncertainty in soil-water-balance evapotranspiration estimates under greenhouse subsurface drip irrigation

Identification

• Journal: Agricultural Water Management
• Year: 2026
• Date: 2026-07-10
• Authors: You Hu, Huaming Zhang, Sheng Deng, Lifeng Wu, Jinjin Zhu, Bingcheng Si, Min Li
• DOI: 10.1016/j.agwat.2026.110604

Research Groups

• Jiangxi Academy of Water Science and Engineering
• Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University
• Jiangxi Provincial Technology Innovation Center for Ecological Water Engineering in Poyang Lake Basin
• Ludong University
• Jiangxi University of Water Resources and Electric Power

Short Summary

This study evaluates the use of actively heated fiber optics (AHFO) sensing to quantify spatial-support uncertainty in soil-water-balance evapotranspiration estimates under greenhouse subsurface drip irrigation. The results show that AHFO can provide reliable soil water content measurements at multiple depths, reducing representativeness uncertainty and improving ETc act estimation accuracy.

Objective

• To evaluate the use of actively heated fiber optics (AHFO) sensing to quantify spatial-support uncertainty in soil-water-balance evapotranspiration estimates under greenhouse subsurface drip irrigation.
• To characterize horizontal and vertical soil water variability and identify time-stable representative support positions.
• To quantify how observation support scale affects root-zone water storage and soil-water-balance ETc act estimation across irrigation treatments.

Study Configuration

• Spatial Scale: Greenhouse plots (8.0 m long, 0.8 m wide) with subsurface drip irrigation system.
• Temporal Scale: Monitoring period from September 19 to November 14, 2020.

Methodology and Data

• Models used: Soil water content balance method for ETc act estimation.
• Data sources: Actively heated fiber optics (AHFO) sensing data, time-domain reflectometry (TDR) measurements, and irrigation schedule.

Main Results

• AHFO-derived soil water content agreed well with TDR measurements at 0.10–0.30 m depths, with R² values of 0.97–0.95.
• Multi-depth AHFO heatmap revealed strong depth-dependent and spatially heterogeneous soil water dynamics along the monitored transect.
• Irrigation events produced visible increases in soil water content, but responses were not uniform along the transect or across depths.

Contributions

• This study provides a novel approach to quantify spatial-support uncertainty in soil-water-balance ETc act estimation under greenhouse subsurface drip irrigation using AHFO sensing.
• The results highlight the importance of considering observation support scale when estimating ETc act, and demonstrate the potential of AHFO for improving ETc act accuracy.

Funding

• This research was funded by the Jiangxi Academy of Water Science and Engineering (Grant No. 2020-JAWS-E001).
• Additional funding was provided by the Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University (Grant No. 2020-KLASWE-A001).

Citation

@article{Hu2026Multidepth,
  author = {Hu, You and Zhang, Huaming and Deng, Sheng and Wu, Lifeng and Zhu, Jinjin and Liao, Cheng and Si, Bingcheng and Li, Min},
  title = {Multi-depth actively heated fiber optics sensing quantifies spatial-support uncertainty in soil-water-balance evapotranspiration estimates under greenhouse subsurface drip irrigation},
  journal = {Agricultural Water Management},
  year = {2026},
  doi = {10.1016/j.agwat.2026.110604},
  url = {https://doi.org/10.1016/j.agwat.2026.110604}
}