Model for planning site-specific nitrogen fertilization of barley in northern conditions

Nitrogen is essential for crop cultivation. Understanding the nitrogen cycle and the factors contributing to the availability of nitrogen for the crops enables estimating the need for additional fertilizer inputs during the growing season. Several computational models have been proposed for this purpose. We propose an alternative approach that predicts crop nitrogen uptake from estimated site-specific nitrogen uptake efficiency and soil moisture. We measured the model accuracy to predict crop yield and nitrogen content in barley, using data collected from two test sites during multiple growing seasons. The model achieved index of agreement of 0.97 for yield prediction and 0.93 for absolute nitrogen content. A global sensitivity analysis was further performed on the model to describe how its outputs can be attributed to the model inputs, showing the most and least influential variables in the model.