AquaCrop model simulation under different irrigation water and nitrogen strategies

Area of Science:

• Agricultural Science
• Crop Modeling
• Water Resource Management

Background:

• Irrigated agriculture accounts for 72% of global freshwater use.
• Deficit irrigation offers a strategy to conserve water while ensuring crop production.
• The AquaCrop model provides a robust, data-efficient simulation tool for irrigation and nitrogen management.

Purpose of the Study:

• To simulate canopy cover, grain yield, and water use efficiency (WUE) for soybean using the AquaCrop model.
• To evaluate the model's accuracy under various deficit irrigation and nitrogen application scenarios.
• To assess the utility of AquaCrop for optimizing soybean water productivity.

Main Methods:

• Field experiments with a line source sprinkler system were conducted over two seasons.
• Soybean was subjected to full and deficit irrigation with varying nitrogen fertilizer rates.
• The AquaCrop model was employed to simulate key crop parameters.

Main Results:

• The AquaCrop model accurately predicted soybean yield, canopy cover, and WUE, with errors below 23%.
• Simulated canopy progression closely matched measured data, achieving a Willmott's index of agreement ≥0.95.
• The model demonstrated proficiency in simulating WUE under diverse irrigation and nitrogen conditions.

Conclusions:

• The AquaCrop model is a valuable tool for simulating soybean growth and water use efficiency.
• It provides reliable predictions for managing irrigation and nitrogen, enhancing crop water productivity.
• The model supports informed decision-making in agricultural water resource management.