E-ISSN 2705-3954 | ISSN 0794-4756
 

Original Research 


Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria

Donatus Obiajulu Onwuegbunam, Habibu Ismail, Nancy Esohe Onwuegbunam, Oluwaseyi Kayode Fadele, Akinrinshola Dare.


Abstract
The need for decision-support tools to aid well-informed water use has become a critical priority in irrigated agriculture as climate change effects prolong dry spells, increase variability in rainfall, and exacerbate the water scarcity situation. The study's objective is to evaluate the performance of the AquaCrop model (version 7.1) in simulating yield, biomass, and crop evapotranspiration (ET) of UC 82B tomato cultivar under drip irrigation in Kaduna, Nigeria. The methodology comprised a calibration of the model in the first irrigation season using field data from nine growth-stage-based deficit irrigation treatments and a full irrigation treatment, and its validation in the second season. The simulation results were evaluated using standard statistical indicators. Both calibration and validation results showed excellent agreement between measured and simulated values, with r2 values > 0.90 for fruit dry yield and biomass, and ≥ 0.90 for ET. The prediction errors were low: ≤ 5.4% for yield, 4.7% for biomass, and 5.2% for ET, implying very strong model performance. The Nash–Sutcliffe efficiency (NE) ≥ 0.80, normalized root mean square error (NRMSE) ≤ 5%, and confidence index (c) > 0.85 indicated a high simulation efficiency of AquaCrop 7.1 for UC 82B tomatoes, and a demonstration of its reliability in predicting tomato crop yield and water use under varied irrigation regimes. The calibration of AquaCrop 7.1 for UC 82B tomato is unique as it provides a cultivar- and region-specific model for drip-irrigated, growth-stage-based deficit conditions, appropriate for promoting sustainable water resources management within Nigeria's Northern Guinea Savanna agro-ecological zone.

Key words: Simulation, AquaCrop, Deficit irrigation, Tomato, Kaduna


 
ARTICLE TOOLS
Abstract
PDF Fulltext
How to cite this articleHow to cite this article
Citation Tools
Related Records
 Articles by Donatus Obiajulu Onwuegbunam
Articles by Habibu Ismail
Articles by Nancy Esohe Onwuegbunam
Articles by Oluwaseyi Kayode Fadele
Articles by Akinrinshola Dare
on Google
on Google Scholar

How to Cite this Article
Pubmed Style

Onwuegbunam DO, Ismail H, Onwuegbunam NE, Fadele OK, Dare A. Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. NJE. 2025; 32(3): 1-9.


Web Style

Onwuegbunam DO, Ismail H, Onwuegbunam NE, Fadele OK, Dare A. Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. https://www.njeabu.com.ng/?mno=277744 [Access: February 09, 2026].


AMA (American Medical Association) Style

Onwuegbunam DO, Ismail H, Onwuegbunam NE, Fadele OK, Dare A. Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. NJE. 2025; 32(3): 1-9.



Vancouver/ICMJE Style

Onwuegbunam DO, Ismail H, Onwuegbunam NE, Fadele OK, Dare A. Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. NJE. (2025), [cited February 09, 2026]; 32(3): 1-9.



Harvard Style

Onwuegbunam, D. O., Ismail, . H., Onwuegbunam, . N. E., Fadele, . O. K. & Dare, . A. (2025) Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. NJE, 32 (3), 1-9.



Turabian Style

Onwuegbunam, Donatus Obiajulu, Habibu Ismail, Nancy Esohe Onwuegbunam, Oluwaseyi Kayode Fadele, and Akinrinshola Dare. 2025. Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. Nigerian Journal of Engineering, 32 (3), 1-9.



Chicago Style

Onwuegbunam, Donatus Obiajulu, Habibu Ismail, Nancy Esohe Onwuegbunam, Oluwaseyi Kayode Fadele, and Akinrinshola Dare. "Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria." Nigerian Journal of Engineering 32 (2025), 1-9.



MLA (The Modern Language Association) Style

Onwuegbunam, Donatus Obiajulu, Habibu Ismail, Nancy Esohe Onwuegbunam, Oluwaseyi Kayode Fadele, and Akinrinshola Dare. "Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria." Nigerian Journal of Engineering 32.3 (2025), 1-9. Print.



APA (American Psychological Association) Style

Onwuegbunam, D. O., Ismail, . H., Onwuegbunam, . N. E., Fadele, . O. K. & Dare, . A. (2025) Calibration and Validation of the AquaCrop Model for Drip-Irrigated Tomato under Growth-Stage-Based Deficit Irrigation in Kaduna, Northern Guinea Savanna, Nigeria. Nigerian Journal of Engineering, 32 (3), 1-9.