RESPONSE OF MAIZE TO PHOSPHORUS FERTILIZATION ON HYDROMORPHIC SOIL OF BOSNIAN POSAVINA AREA

In a four year experiment the effect of ameliorative phosphorus (P) fertilization (0, 750, 1250 and 1750 P2O5 kg ha-1 in the form of triple superphosphate containing 45% P2O5) on maize grain yields and maize nutrient status (the ear-leaf at silking) was examined. P fertilization resulted mainly in considerable yield increase being 17% (4-year means 2005-2008: 4.30 and 5.02 t ha-1, for control and ameliorative P-fertilized treatments, respectively). Yield increases were achieved mainly by application of the first step of P in level of 750 kg P2O5 ha-1, while differences among P treatments were significant only in the second year of testing. P application had significantly influence on P, Mg, Mn and Zn status in maize leaves (0.36 and 0.56% P, 0.61 and 0.77% Mg, 53.3 and 69.2 mg Mn kg-1, 68.0 and 41.1 mg Zn kg-1, for control and 1750 kg P2O5 kg ha-1, respectively), while differences in leaf K, Ca, S Fe and Cu were non-significant (means 1.05% K, 0.83% Ca, 0.23% S, 148 mg Fe kg-1 and 11.1 mg Cu kg-1). Protein, starch and oil contents in maize grain (2-year means: 8.83%, 72.04% and 3.78%,respectively) were independent on P fertilization.