EFFECT OF NITROGEN FERTILIZATION IN TRITICALE (X TRITICOSECALE WITTM.), CULTIVATED AFTER DIFFERENT PREDECESSORS. NITROGEN UPTAKE AND EFFICIENCY

Abstract

The study is conducted at the experimental base of Department of Plant production
at Trakia University, Stara Zagora. Triticale is grown after five predecessors and
different nitrogen fertilization rates. The predecessors are wintering peas, spring
peas, sunflower, common wheat and triticale. Nitrogen fertilization rates are 0 (N0),
40 (N40), 80 (N80), 120 (N120) kg ha-1 after legumes and 0 (N0), 60 (N60), 120 (N120),
180 (N180) kg ha-1 after the other predecessors. The influence of the predecessors
and nitrogen fertilization on the nitrogen uptake, assimilated nitrogen from
fertilization, nitrogen utilization and nitrogen required for 100 kg produce of
triticale is established. Nitrogen assimilation from fertilization increases with the
increase of the nitrogen fertilizer rates. With the obtained yield from triticale an
average of 96.53 kg ha-1 N is extracted from the soil with the grain, 18.97 kg ha-1 N
with the straw or a total of 115.50 kg ha-1 N. When growing triticale after
leguminous predecessors the utilization of nitrogen is 35.39% and after
predecessors sunflower, wheat and triticale - 28.76%. Nitrogen required for 100 kg
yield of grain of triticale is 1.9 kg of nitrogen when growing after legume
predecessors and 2.8 kg of nitrogen after the other predecessors.