Evaluation of model-based site-specific nitrogen applications on wheat yield and environmental quality

摘要

Crop growth models have been used in the past to study causes of yield variability and to estimate the economic consequences of variable nitrogen rate prescriptions. In this study, the APOLLO model, which is based on the DSSAT crop growth model family, was implemented to develop optimum site-specific nitrogen management prescriptions for wheat. The nitrogen prescription was targeted to maximize the long-term marginal net return, which includes an economic penalty for leaving excess nitrogen in the root zone at harvest. By using two constraints (wheat yield and environmental quality), it is expected that the simulation can find prescriptions that maximize marginal net return while reducing the amount of nitrogen losses to surface and groundwater sources at the sub-field scale.