[Application of DNDC model in estimating cropland nitrate leaching]

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Nitrate leaching from agricultural fields poses environmental risks.
• Accurate modeling is crucial for managing nutrient loss in winter wheat cultivation.
• Lysimeter data provides direct measurements of soil water and nitrate movement.

Purpose of the Study:

• To measure soil water and nitrate leaching in a winter wheat field.
• To evaluate the feasibility of the DNDC model for simulating these processes.
• To identify factors influencing nitrate leaching and model accuracy.

Main Methods:

• Field measurements using lysimeters during the 2008 winter wheat growing season.
• Application and validation of the DNDC (DeNitrification-DeComposition) model.
• Sensitivity analysis of the DNDC model concerning environmental factors.

Main Results:

• The DNDC model showed acceptable accuracy in simulating soil water movement.
• Simulated nitrate leaching (18.35 kg N/hm²) exceeded observed values (14.89 kg N/hm²) by approximately 20%.
• Model sensitivity tests indicated irrigation and fertilization as key factors influencing nitrate leaching.

Conclusions:

• The DNDC model demonstrates applicability for simulating soil water and nitrate dynamics in the study area.
• Further refinement of model parameters is necessary to improve nitrate leaching simulation accuracy.
• Understanding the impact of irrigation and fertilization is vital for mitigating nitrate loss.