Numerical Modeling to Study the Fate of Nitrogen in Cropping Systems and Best Management Case Studies

Summary

Nitrogen (N) availability for crop uptake is dependent on various factors that influence the transformation of N sources and transport of N forms in soils. The fate and transport of N is site specific. Therefore evaluation of N dynamics under each condition is neither practical nor feasible. Simulation models which are adequately calibrated and tested can be used to estimate the fate and transport of N as well as crop responses under different production systems. These evaluations provide some guidelines as how to manage N and water efficiently to maximize the N uptake efficiency and minimize the losses. Thus, they contribute to the development of N and water best management practices. In this chapter, we discuss recent information on experimentally measuring the water and nutrient transport in soils as well as performing estimations using simulation models. The development and application of different simulation models for different production systems have been summarized. Some case studies on nitrogen and water best management practices are also discussed.

Key Words:

• Best management practices
• crop rotations
• fertigation
• leaching estimation and chemistry model
• nitrate leaching and economic analysis package
• nitrate leaching index
• nitrogen uptake efficiency
• optimal nitrogen
• rootzone water quality model
• simulation models
• water balance estimations