The effect of nitrogen fertilizer rates on green biomass and dry matter yield of Sorghum sp. at different growth stages

Abstract

The paper investigated the production properties of three sorghum genotypes: NS-Džin (forage sorghum), Zora (Sudan grass) and Siloking (interspecies hybrid) in terms of different nitrogen rates used in side dressing in 2009 and 2010. The subject of study was green biomass and dry matter yield in the stages of intensive growth and tasseling. The results have shown that there have been significant fluctuations in production indicators between the genotypes. In the total average, the lowest yield was recorded for the Sudan grass (85.41 t ha-1). Significantly higher yields were recorded for the interspecies hybrid (90.22 t ha-1) and the forage sorghum (93.51 t ha-1). Although the effect of nitrogen rates depended on weather conditions, i.e. rainfall distribution, the optimal nitrogen rate in both years was 180 kg ha-1.

U radu su proučavane produktivne osobine tri genotipa sirka i to: NS-Džin (krmni sirak), Zora (sudanska trava) i Siloking (interspecijes hibrid) u zavisnosti od upotrebljenih količina azota za dopunsku ishranu biljaka tokom 2009. i 2010. godine. Ispitivani su prinos zelene mase u fazama intezivnog porasta i metličenja. Između ispitivanih genotipova postoje značajna variranja u pokazateljima produktivnosti. U ukupnom proseku najmanji prinos dala je sudanska trava 85,41 t ha-1. Značajno viši prinos bio je kod interspecijes hibrida (90,22 t ha-1) i krmnog sirka (93,51 t ha-1). Iako je efekat upotrebljenog azota zavisio od vremenskih uslova, odnosno od rasporeda padavina, u obe godine optimalna količina azota bila je 180 kg ha-1.