A bug causing uptake of mineral N from deeper soil layers after a plant was disappearing by some reasons like harvesting was discovered and corrected. The Update rate was causing losses from the soil but was not linked with any plant. This resulted in an error shown in the “Nitrogen Balance Check” output variable.
Another bug also shown in the “Nitrogen Balance Check” was caused by an error in the updating of the Growth Stage Index output variable. The Growth Stage Index was reset to 1 at year shift proving that it was below 2. This in turn caused an additional emergence that replaced current plant by a new initiated by a seed. The error in nitrogen balance was related to the difference in the actual carbon and nitrogen of plant compared to the new seed.
Thanks to Elsa Coucheney that identified this two bugs by a notice on the behaviour of the Nitrogen Balance Check output variable. If you have made simulations with plants with a dynamics Growth Stage Index lower than 2. Please make an inspection of your results and report your findings.