THE EFFECT OF NITROGEN FERTILISERS ON THE GRAIN YIELD OF DIFFERENT CULTIVARS OF WINTER WHEAT

Abstract

The article deals with the effect of nitrogen fertilizer on the yield of different cultivars of winter wheat. Field experiments were conducted in 2011–2013 at the Experimental Station of Aleksandras Stulginskis University in carbonate shallow gleyic leached soil, (Calc(ar)i-Epihypogleyic Luvisol). The object of the investigation was winter wheat cultivars ‘Zentos’ and ‘Ada’. In sowing time the wheat was treated with granular superphosphate (P60) and potassium chloride (K60), and in spring, after the vegetative growth had resumed, in tillering time (BBCH 23–15) with ammonium nitrate (N60). Additionally, foliar fertilizer urea solution was used: N30, N40 at booting stage (BBCH 34–36) and N15, N30 at milk ripening stage (BBCH 71–74). It has been established that application of nitrogen fertilizer at booting and milk ripening stages increased the yield of wheat cultivars ‘Zentos’ and ‘Ada’ (0.06–1.74 and 0.41–1.74 t ha–1). The correlation and regression analysis confirmed that wheat grain yield statistically significantly correlated with nitrogen fertilizer application rates. The correlative relationships were very strong (r = 0.983 and r = 0.987). Irrespective of additional fertilization, genetic properties of the cultivars also had influence on the yield.