REAKCIJA KUKURUZA NA GNOJIDBU FOSFOROM NA HIDROMORFNOME TLU BOSANSKE POSAVINE

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

Interdependence of yield and soybean yield components

This paper presents the results of a two-year study of six selected soybean genotypes with the aim of examining which of the genotypes in the given production conditions give the best results in regards with the amount and quality of seed yield. All genotypes belong to a zero-maturity group. The correlation between the grain yield per plant and other studied traits was tested through linear (simple) correlations. The testing showed that the following traits had a positive highly significant impact on seed yield: the number of seeds per plant (0.917**), seed germination energy (0.897**), seed moisture content (0.803**), plant height (0.802**), seed germination (0.789**), the number of seeds in pods (0.696**), the number of harvested plants per m-2 (0.590**), the number of plants (phenophase 1-3 in the three-leaf stage) per m2 (0.550**), 1000 seed mass (0.471**), and the height to the first node (0.412**)

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

Comparative Study on Cavitation Erosion Resistance of A356 Alloy and A356FA5 Composite

In the present study, an aluminum alloy A356 composite with addition of 5 wt% fly ash was synthesized and subjected to the cavitation erosion resistance test in order to find out if this material can be used in conditions where the cavitation erosion resistance is expected. Obtained results were compared with that of as-cast aluminum A356 alloy, confirming that composite possessed better cavitation erosion resistance than original alloy and that fly ash can be used as an effective reinforcement in metal matrix composites production. Scanning electron microscopy and optical microscopy was used for microstructural analysis. Phase identification of fly ash was carried out using X-ray diffraction analysis. Several methods for monitoring the cavitation erosion resistance of A356 alloy and corresponding composite were applied, such as: mass loss (Delta m), volume loss (Delta V), level of surface degradatiom (P/Po) and pit depth