Single and split nitrogen dose in wheat yield indicators

Dose única e fracionada do nitrogênio nos indicadores de produtividade do trigo

ABSTRACT

Single or split nitrogen (N) supply can maximize the expression of wheat yield indicators. The objective of the study was to evaluate the greater N use efficiency on wheat yield indicators by the single and split N supply under favorable and unfavorable year conditions to the crop in succession system of high and reduced residual N release. The study was conducted in 2014 and 2015, in a randomized complete block design with four replicates in a 4 x 3 factorial, for N-fertilizer doses (0, 30, 60, 120 kg ha^-1) and supply forms [full dose (100%) in the phenological stage V₃ (third expanded leaf); split dose (70 and 30%) in the phenological stages V₃/V₆ (third and sixth expanded leaves, respectively) and; split dose (70 and 30%) in the phenological stages V₃/R₁ (third expanded leaf and early grain filling)], respectively, in soybean/wheat and maize/wheat cultivation systems. The highest N use efficiency for wheat yield was obtained with the single dose supply in favorable year of temperature and rainfall and with the split dose in the V₃/V₆ stages in unfavorable year, regardless of the succession system of high and reduced residual N release.

Key words:
Triticum aestivum; urea; residual N; temperature; rainfall