Enhancing soil moisture retrievals from cosmic ray neutron sensor in a peri-urban agricultural landscape

Noč, Matic (author), Golob, Nejc (author), Pirnat, Matjaž (author), Pečan, Urša (author), Srdoč, Špela (author), Švegelj, Žiga (author), Zupanc, Vesna (author), Železnikar, Špela (author), Žvokelj, Luka (author), Cvejić, Rozalija (author)

Cosmic ray neutron sensors (CRNS) provide continuous, non-invasive monitoring of soil water content (SWC) at intermediate spatial scale, while their accuracy in heterogeneous landscapes remains less explored. In this study, a CRNS deployed in a peri-urban patchy agricultural landscape was calibrated using five gravimetric campaigns. SWC measured with CRNS was compared with the mean in situ SWC from a network of nine frequency domain (FD) sensors. Weighted mean volumetric SWC closely matched daily in situ measurements at 10 cm depth (mean difference = 1.7 vol% ± 1.5 vol%). Using the gravimetric sampling campaign with mean SWC near field capacity, combined with corrections for air pressure, incoming muons, water vapor and the short-term JUNG correction, resulted in the lowest RMSE for the measurement period, with a value of 3.81 vol%. Correlation between CRNS and in situ SWC was high and significant (ρ = 0.84, p < 0.001). Monthly differences between the in situ sensor and the calibrated CRNS SWC were generally below 5 vol%, with no significant differences observed during late summer periods. These results demonstrate that locally calibrated CRNS is suitable for drought monitoring at a heterogeneous rainfed landscape, while its use for other objectives, such as precision irrigation, requires further validation.

• Language: English
• Keywords: cosmic ray neutron sensor, calibration, frequency domain, drought onset detection
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 13 str.
• Numbering: Vol. 333, art.110564
• PID: 20.500.12556/RUL-184097
• UDC: 631
• ISSN on article: 0378-3774
• DOI: 10.1016/j.agwat.2026.110564
• COBISS.SI-ID: 282816003
• Publication date in RUL: 26.06.2026

Record is a part of a journal

• Title: Agricultural water management
• Shortened title: Agric. water manage.
• Publisher: Elsevier
• ISSN: 0378-3774
• COBISS.SI-ID: 26708224

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: vlaga v tleh, senzorji, monitoring, talna vlaga, suša, namakanje