Faculty of Agrobiotechnical Sciences Osijek and Agricultural Institute Osijek
Abstract
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.Istraživan je utjecaj melioracijske gnojidbe fosforom (0, 750, 1250 i 1750 P2O5 kg ha-1 u obliku trostrukoga superfosfata 45% P2O5) na prinose i stanje ishrane kukuruza (list ispod klipa u svilanju). Gnojidba fosforom povećala je prinose kukuruza u prosjeku za 17% (4-g prosjek 2005.-2008.: 4.30 i 5.02 t ha-1, na kontroli i na tretmanima gnojidbe fosforom). Povećanje prinosa uslijedilo je već primjenom 750 kg P2O5 ha-1, a statistički značajne razlike između pojedinih stepenica dodanoga P bile su evidentne samo u 2006. godini. Melioracijska gnojidba fosforom značajno je utjecala na koncentracije P, Mg, Mn i Zn u listu (0,36 i 0,56% P; 0,61 i 0,77% Mg; 53,3 i 69,2 mg Mn kg-1; 68,0 i 41,1 mg Zn kg-1 za kontrolu, odnosno 1750 kg P2O5 kg ha-1), dok su koncentracije K, Ca, S, Fe i Cu bile slične (prosjeci 1,05% K, 0,83% Ca, 0,23% S, 148 mg Fe kg-1 i 11.1 mg Cu kg-1). Sadržaj bjelančevina, škroba i ulja u zrnu (2-god. prosjeci: 8,83%, 72,04%, odnosno 3,78%) bili su neovisni o gnojidbi fosforom
