AgricultureAgronomyPlant SciencesPlant NutritionSoil FertilitySoil ScienceNitrogen AssimilationNitrogen CycleNutrient AvailabilitySoil Fertility EvaluationSoil Nutrient AvailabilitySoil-plant Nutrient RelationsCritical Nutrient Dilution CurveCritical Nutrient ThresholdsNitrogen Response ModelingPlant-available NitrogenSoil Nitrogen AssessmentSoil Nitrogen Availability AssessmentSoil Nitrogen Calibration Models