THE EFFECT OF NITROGEN INPUT ON POLARISED SUGAR PRODUCTION AND QUALITATIVE PARAMETERS OF SUGAR BEET

During 1998-2002, the application of different forms and doses of nitrogen on quantitative (polarised sugar production)and qualitative parameters (digestion, molasses forming components - potassium, sodium and α-amino nitrogen content) of sugar beet in vulnerable zones (Nitrate directive) was studied. Calculated input of nitrogen ranged from 12 kg up to 240 kg N.ha-1. By increasing input of N from FYM application into the soil causes an increases of α- amino nitrogen content in root, which in consequence causes a decreases the sugar content (negative correlation r= -0.8659+). The application of straw instead FYM of analogues treatments caused significant decrease (straw versus FYM) and highly significant decrease (straw plus N fertilizers versus FYM plus N fertilizers) of α-amino nitrogen content in sugar beet root living the productive parameters unchanged. The content of α-amino nitrogen in root of sugar beet indicate an environmentally friendly management practices with causal relation to water protection from nitrate