Modeling the effect of abrupt changes in nitrogen availability on lettuce growth, root-shoot partitioning and nitrate concentration

A simplified model, obtained by imposing a fixed RSR, gives predictions of shoot fresh mass, dry matter content, nitrate concentration and reduced-N content similar to the predictions of the model with variable RSR, except for extreme cases in which the plants are N-deprived throughout the whole growing period. This indicates that proper modeling of root-shoot partitioning is not essential for predicting the effect of abrupt changes of nitrogen availability on shoot growth and internal plant composition.