Authors:Zs. Szentpétery, M. Jolánkai, Cs. Kleinheincs, and G. Szöllősi
The effects of nitrogen (N) applications on Hungarian, French and Serbian winter wheat cultivars were studied in field trials, which were conducted from 1996 to 2003 in a central Hungarian region, Hatvan-Nagygombos. Nitrogen fertilizer rates of 0, 40, 80, 120, 40 + 40 and 80 + 40 were applied at tillering and after anthesis fazes (Feekes 3 and Feekes 10.5.). The nitrogen used was 36 % ammonium-nitrate in. Split-split plot design with four replications was used. In the experiment we analysed the changes of quantity and baking quality of yield. Amount of rainfall during the vegetation period had a significant effect on wheat yield. Differences in rainfall during the vegetation period — especially in April and May — had a significant effect, too. It turned out that in drought periods nitrogen top-dressing has a great importance. In the dry 2001–2003 years even the 40 kg/ha dose resulted in extra yield. 80 and 120 kg/ha fertilizer rates was even more effective. The increasing dose of nitrogen top-dressing and its division resulted in this trial in an outstanding quality improving effect in spite of the unfavourable ecological circumstances. Especially great improvement was observed in the case of foreign varieties. Nitrogen top-dressing stabilized the falling number values.
Authors:Attila Szöllősi, László Narr, Attila G. Kovács, and Gabriella Styevkó
Kinetics of growth and product formation of G. toluenoxydans DSMZ 19350 strain were investigated using sodium-acetate as substrate and Fe3+-ions and fumarate as electron acceptor. Response surface method was adapted for evaluation of growth of bacteria. Results showed that maximum growth was detected in the case of 2.2 g/L substrate concentration. Application of higher substrate concentration (>2.5 g/L sodium acetate) significantly inhibits the bacterial growth. Luong’s model was found to be the most suitable to determine kinetic parameters (μmax = 0.033 1/h, KS = 0.205 g/L) of growth of G.toluenoxydans strain, and the growth was completely inhibited at substrate concentration higher than 3.1 g/L. In the case of product formation the Haldane model was used and kinetic parameters are μPmax = 0.123 mg/h, KPS= 0.184 g/L. Correlation between microbial growth and product formation was observed using the Luedeking–Piret empirical method. Both factors (growth and number of cells) affected significantly iron(III)-reduction, thus the product formation. These results are important and open the possibility to design a continuous MFC setting operating with G. toluenoxydans as biocatalyst.
Authors:Zs. Szentpétery, Cs. Kleinheincz, G. Szöllősi, and M. Jolánkai
The effects of nitrogen (N) applications on Hungarian, French and Serbian winter wheat cultivars were studied in field trials conducted from 1996 to 2003 in a central Hungarian region, Hatvan-Nagygombos. Fertilizer rates of 0, 40, 80, 120, 40+40 and 80+40 kg ha-1 active ingredient were applied at tillering and after anthesis (Feekes 3 and Feekes 10.5). The N-fertilizer applied was ammonium-nitrate in 34% cc. Split-split plot design with four replications was used. In the experiment the changes of quantity and baking quality of the yield were analysed. Differences in rainfall during the vegetation period - especially in April and May - had a strong effect on wheat yield. In drought periods N top-dressing had a great importance. In the dry 2001-2003 years, the 80 and 120 kg ha-1 fertilizer doses were the most effective. The increasing dose of N top-dressing and its division resulted in this trial in an outstanding quality improvement in spite of the unfavourable ecological circumstances. Especially, great improvement was seen in case of foreign varieties that were of lower quality compared to the Hungarian ones. The top-dressing stabilized the falling number values in the 250-350 top range.