Changes of nitrogen content in sugar beet during vegetation and its uptake for yield formation

absorption de substances nutritives agronomic characters analisis analyse analyse chimique analysis anatomia anatomie anatomy biological production biomasa biomass biomasse chemical analysis composition contenido de materia seca crops cultivos dry matter content economic plants feuille fisiologia fonction physiologique hojas industrial crops leaves methode methods nitrogen content nutrient uptake physiological functions physiologie physiology plant anatomy plantas plantas azucareras plantas industriales plante plante de culture plante industrielle plante racine plants production production biologique productividad productivity profitability racine remolacha azucarera rendement rendimiento rentabilidad root crops roots storage organs sugar beet sugar crops teneur en azote yields