A fertilizing trial involving red head chicory was set up on anthropogenized garden soil in 1991. Investigations continued for three years and were copleted in 1993. The trial was carried out according to the Latin rectangle method with eight fertilizing variants in four replications. Apart from the unfertilized check variant, the trial included four nitrogen rates and two potassium rates, while phosphorus fertilization was uniform.
Investigation results indicate significant differences in the concentration of nitrates in the concentration of nitrates in chicory both per fertilizing variants and per investigation years. This was certainly influenced by the climate and soil as the main habitat factors, notably the prevailing weather conditions which considerably deviated from the average ones.
It is noteworthy for these investigations that, regardless of fertilization and ivestigation year, all the determined nitrate values of harvested chicory (555 - 1057 mg N03-/kg F. W.) were below tolerance according to international standards for this type of leafy vegetables (1500 - 2500 mg N03-/kg F. W.)

nitrogen fertilization; nitrates; amino acids; head chicory

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia