Modeling Water and Nutrient Movement in Sandy Soils Using HYDRUS-2D.

Area of Science:

• Environmental Science
• Soil Science
• Hydrology

Background:

• Environmental management systems benefit from predictive models for complex processes.
• Sandy soils in Florida require efficient irrigation and nutrient management strategies.

Purpose of the Study:

• Calibrate and validate the HYDRUS-2D model for water and solute transport in Candler and Immokalee fine sands.
• Investigate the movement of bromide, nitrate, and water under various irrigation and fertigation scenarios.

Main Methods:

• Model simulations using HYDRUS-2D with data from microsprinkler and drip irrigation.
• Calibration and validation against field data for soil water content and nutrient movement.
• Analysis of annual/seasonal weather data and variable fertigation scenarios.

Main Results:

• HYDRUS-2D demonstrated good agreement between simulated and measured values for soil water content (R²=0.87-1.00), bromide (R²=0.63-0.96), nitrate-N (R²=0.66-0.98), phosphorus (R²=0.25-0.78), and potassium (R²=0.44-0.99).
• The model successfully predicted nutrient leaching and water movement.

Conclusions:

• HYDRUS-2D is a reliable decision support system for managing water and nutrients in Florida's sandy soils.
• The model can aid in optimizing irrigation scheduling and predicting nutrient leaching for both microsprinkler and drip systems.