Parameter settings of the control unit for automated drip irrigation for the use in the greenhouse using HYDRUS 2D/3D numerical simulations

B.Sc. Oluwatobi Ayodele Alamu, BSc

Master's thesis

Abstract:

As the population increase and the demand for water was getting higher, more focus was put on the agricultural sector to manage water efficiently while producing food. Drip irrigation technology offers the best control over the application of water. Drip irrigation technology demands for the optimization of the operational parameters such as duration of irrigation, frequency, and emitter discharge rate. Numerical simulation offers applicable approach to evaluate the efficiency of drip management practises. Numerical simulation was carried out with Hydrus 2D/3D to investigate the significant effect of moisture content, pressure head, volume of water applied, and soil hydraulic properties on different irrigation schemes. Good knowledge about the horizontal and vertical distances by which water spreads under a point source is important to the design efficient and effective surface drip irrigation. Two different irrigation schedules were made which were triggered irrigation and planned irrigation, Different irrigation schemes were simulated, one hour of irrigation and two hours of irrigation every day for 2 weeks was compared to evaluate the level of pressure head, moisture content and the effect of different hydraulic conductivity on the volume of water applied during irrigation. The simulation results show that the higher the hydraulic conductivity the higher the amount of water needed for the triggered irrigation, as water is transported fasted into the deeper parts of the profile. Planned irrigation scheme is not able to adjust to possible changes in saturated hydraulic conductivity within the vegetation season. Correlation between hydraulic conductivity value and the amount of water used was also observed for different irrigation duration and 2 hours irrigation every day for 2 weeks. Regular every day irrigation of 2 hours was found to be the best suitable considered greenhouse installations. Graphical and numerical outputs from the Hydrus simulation software offers a wide range of possible comparisons enabling comparisons of moisture contents and pressure head changes within the profile for given pre-set print times. As evapotranspiration was considered in the simulations, considerable moisture content changes were observed on the surface. For installations with high potential evapotranspiration rates, subsurface drip irrigation would be the most water-saving strategies reducing the evaporation and water requirements, because water can be delivered straight to the root zone.

Keywords

Surface Drip Irrigation, Numerical Simulation, Operational Parameters, Irrigation Frequency, HYDRUS 2D/3D

Language used: English

Date on which the thesis was submitted / produced: 27. 4. 2021

Thesis defence

• Supervisor: Ing. Kamila Báťková, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Natural Resources and Environment / Natural Resources and Environment