Dissertation
Interpreting Uncalibrated Soil Water Content Sensors Dynamics for Irrigation Management
Washington State University
Doctor of Philosophy (PhD), Washington State University
2022
DOI:
https://doi.org/10.7273/000005228
Abstract
Soil moisture sensors used to monitor the soil water status are one of the keys to delivering the right amount of water at the right time to satisfy crop water requirements. However, installation, calibration, and maintenance of soil moisture sensing devices and interpretation of data are complicated and tedious for most farmers. Furthermore, the variability, heterogeneity, and complexity of soils and how that interacts with individual soil moisture sensors and those sensors’ installation results in inaccurate soil moisture information. The research aims to analyze the soil moisture data signals to estimate field capacity from soil moisture dynamics to assess the field capacity (FC) or "full point" and management allowable deficit (MAD) or "refill point" for irrigation management. The objectives of the research are to use soil moisture dynamics alone to estimate FC (full point) and MAD (refill points) for irrigation management; and to describe best practices for using soil moisture sensors alone to quantify ET and as well as some of the challenges. Results show that the developed algorithm, with simple interpretation and easy calculation, defines FC values from the soil water content sensor data that were reasonable as verified using data from soil water potential sensors co-located with the soil water content sensors. Using the method of estimating field capacity and literature values of FC, PWP, and MAD by different soil textures, we can also identify a usable refill point of the soil. Lastly, there are large uncertainties and inherent variabilities in measuring the consumptive use, or evapotranspiration (ET), using the soil water balance come from the uncertainties and unknowns in measuring deep percolation and capillary rise, and from installation, inaccuracies, and interpretation of soil water content sensors.
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Details
- Title
- Interpreting Uncalibrated Soil Water Content Sensors Dynamics for Irrigation Management
- Creators
- John Paulo Caraan Sacdalan
- Contributors
- R. Troy Peters (Advisor)Colin Campbell (Committee Member)Manoj Karkee (Committee Member)Kirti Rajagopalan (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 55
- Identifiers
- 99901019237501842
- Language
- English
- Resource Type
- Dissertation