Winter wheat yields as affected by year and nitrogen rate applied

Abstract

A 10-year study was conducted over 1995-2004 in order to study the effects of different N rates on grain yields of three winter wheat varieties having different yield and quality potentials. The study was part of a larger stationary trial carried out at the Rimski Sancevi site near Novi Sad.

The experiment included four N fertilization treatments. The study years were divided into three groups depending on the yield levels they produced: 1) favorable, or high-yielding years (average yields of over 6 tha^-1), intermediate ones (5-6 tha^-1 on average), and unfavorable or low-yielding ones (yields of less than 5 tha^-1). The study determined the effect of three study factors (year, N fertilizer, and cultivar) and their interactions on yield levels in wheat.

In each N treatment individually as well as on average, the highest grain yield was produced by the variety Pobeda and the lowest by the variety Sremica. The highest average grain yield was achieved with the highest N rate (180 kg ha^-1), but this yield did not differ significantly from that obtained using 120 kg N ha^-1. Yield levels were affected the most by year, N rate and year x N rate interaction, while cultivar produced a significantly lower effect.