Spinach production is based on a conventional cultivation system. This form of culttvat1on,
due to excessive use of mineral fertilizers, pesticides and other inputs in production, can lead to
an unbalanced relation and disruption of natural processes in the soil. Due to this
fact, various spinach fertilization systems are being examined in order to ensure health value and
environmental protection. A two-factorial (locality and fertilization) one-year study was
conducted by random block schedule in four replications. The study examined the influence of
different localities (Krizevci in Croatia and Velika Kladusa in Bosnia and Herzegovina) and
fertilization systems (mineral, reduced mineral and organic) on yields and nitrate
concentrations, as well as the amount of vitamin C in the spinach variety Norvak. Analysis of
variance indicates a high and statistically justified (p < 0.05) influence of
localities and fertilization on height, spinach yield and nitrate concentration. Due
to economic and environmental justification, a reduced mineral fertilization system
should be applied in further practice, because the obtained yield and yield components do
not differ statistically from those obtained using mineral fertilization, and benefits are
multiple (better product quality and less environmental pollution).
Key words: mineral fertilization system, organic fertilization system, quality,
reduced mineral fertilization system, spinach, yield
