{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T15:31:19Z","timestamp":1787585479377,"version":"build-2736575974"},"reference-count":21,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"TUNGER 2+2 bilateral cooperation","award":["20_046"],"award-info":[{"award-number":["20_046"]}]},{"name":"German Federal Ministry of Education and Research"},{"id":[{"id":"https:\/\/ror.org\/04pz7b180","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Tunisian Ministry of Higher Education and Scientific Research"},{"name":"EcofertiSH project","award":["ANR-24-P013-0010"],"award-info":[{"award-number":["ANR-24-P013-0010"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Water scarcity in semi-arid regions makes efficient irrigation scheduling a priority, yet farm-level adoption of soil-moisture monitoring remains limited by the cost, low portability and installation complexity of commercial sensing systems. This study presents the development and field validation of WaziSense, a low-cost, solar-powered Internet-of-Things (IoT) smart tensiometer, developed within the OSIRRIS platform for soil-water monitoring and irrigation scheduling. The device couples a Watermark granular-matrix sensor and a DS18B20 temperature probe to an ATmega328P microcontroller (Arduino Pro-Mini, 3.3 V, 8 MHz) with long-range LoRa communication and a maximum-power-point-tracking (MPPT) solar-charging stage, logging soil matric potential and soil temperature every 15 min. An open-source edge\/cloud stack (WaziGate, WaziApp) retrieves weather forecasts from an open API and runs an automated machine learning (AutoML) regression pipeline that forecasts soil-water dynamics and the time to a user-defined threshold, from which irrigation is scheduled and its applied volume verified by a flow meter. The system was deployed at three bioclimatic sites in Tunisia (durum wheat at Cherfech, citrus at Nabeul, apple at Sbeitla), with tensiometers installed at 20 and 40 cm depths, and validated against commercial 10HS capacitive probes coupled to a ZL6 data logger, with which the co-located readings were significantly correlated (r = 0.81). Calibrated readings showed a strong relationship between soil\u2013water content and soil\u2013water potential (R2 = 0.99), and the edge forecasting model reproduced soil\u2013water dynamics on unseen data (Sbeitla apple site, 5-day horizon) with R2 = 0.73, RMSE = 0.35, MAE = 0.23 and MPE = 12.52%. With a material cost under about 90 EUR per node and fully open-source hardware and software, WaziSense is one to two orders of magnitude cheaper than commercial monitoring stations, offering an affordable, reproducible and scalable tool for data-driven irrigation in water-limited agriculture.<\/jats:p>","DOI":"10.3390\/s26175348","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T14:49:34Z","timestamp":1787582974000},"page":"5348","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Development and Field Validation of WaziSense, a Low-Cost Solar-Powered IoT Smart Tensiometer for Soil\u2013Water Monitoring and Irrigation Scheduling in Semi-Arid Agriculture"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4627-6526","authenticated-orcid":false,"given":"Hassine","family":"Ben Abdallah","sequence":"first","affiliation":[{"name":"National Institute for Research in Rural Engineering, Water and Forestry (INRGREF), University of Carthage, Ariana 2080, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-3072-806X","authenticated-orcid":false,"given":"Liliya","family":"Naui","sequence":"additional","affiliation":[{"name":"National Institute for Research in Rural Engineering, Water and Forestry (INRGREF), University of Carthage, Ariana 2080, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-9759-9832","authenticated-orcid":false,"given":"Mourad","family":"Bakri","sequence":"additional","affiliation":[{"name":"National Institute for Research in Rural Engineering, Water and Forestry (INRGREF), University of Carthage, Ariana 2080, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-4514-4085","authenticated-orcid":false,"given":"Felix","family":"Markwordt","sequence":"additional","affiliation":[{"name":"Waziup e.V., R\u00e4cknitzh\u00f6he 50\/52, 01217 Dresden, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed Abdur","family":"Rahim","sequence":"additional","affiliation":[{"name":"Waziup e.V., R\u00e4cknitzh\u00f6he 50\/52, 01217 Dresden, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9076-7613","authenticated-orcid":false,"given":"Corentin","family":"Dupont","sequence":"additional","affiliation":[{"name":"Waziup e.V., R\u00e4cknitzh\u00f6he 50\/52, 01217 Dresden, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4699-6483","authenticated-orcid":false,"given":"Mohamed Ali","family":"Ben Abdallah","sequence":"additional","affiliation":[{"name":"National Institute for Research in Rural Engineering, Water and Forestry (INRGREF), University of Carthage, Ariana 2080, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0908-7598","authenticated-orcid":false,"given":"Mourad","family":"Rezig","sequence":"additional","affiliation":[{"name":"National Institute for Research in Rural Engineering, Water and Forestry (INRGREF), University of Carthage, Ariana 2080, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Hardie, M. 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