Mitteilungen der Gesellschaft für Pflanzenbauwissenschaften Band 23

Mitt. Ges. Pflanzenbauwiss. 23: 142–143 (2011)
Influence of N fertilization and genotype
on N retranslocation during reproductive growth in oilseed rape
Abdullah Ulas 1 , Torsten Behrens 1 , Franz Wiesler 2 , Walter J. Horst 1 and
Gunda Schulte auf`m Erley 1
1
Institute for Plant Nutrition, Leibniz University of Hannover;
schulteaufmerley@pflern.uni-hannover.de
2 LUFA, Speyer. E-Mail:
Introduction
Oilseed rape is one of the crops with the highest N balance surpluses in European
agriculture. The high surpluses are mainly caused by two processes, a low N
recovery from the soil and an incomplete N retranslocation from the vegetative
biomass into the seeds. Genotypic variation in N uptake was found, which was
related to yield at limiting and high N supply (Schulte auf’m Erley et al., 2011). The
incomplete N retranslocation from vegetative plant parts has mostly been ascribed to
insufficient leaf N retranslocation prior to leaf fall. N recoveries from leaves have
been studied in detail for oilseed rape (Malagoli et al., 2005; Gombert et al. 2010),
but no reports on genotypic variation in this trait are available yet.
Materials and Methods
Four winter oilseed rape cultivars differing in N efficiency were grown at three N rates
in a three-year field experiment performed south of Göttingen. Harvests were
performed at the beginning of flowering and at maturity. Plants were fractionated into
stems, leaves, pod walls and seeds. In addition, dead leaves were collected weekly
between beginning of flowering and maturity from mesh nets placed into the plots.
Dry weights and N contents of all plant fractions were determined.
Results and Discussion
Cultivars differed in seed yield at all N rates (Table 1). Cultivar Apex could be
characterized as N-efficient due to its highest yield at low N, while cv Bristol was
superior in seed yield at high N supply. The high N efficiency of cv Apex was related
to a high N uptake, while the superior yield of cv Bristol at high N was only partly due
to superior N uptake.
Table 1: Seed yield and N uptake of four winter oilseed rape cultivars grown at three
N rates (N0: soil Nmin; N120: 120 kg N ha -1 ); N 240: 240 kg N ha -1 ) in a three-year
field experiment.
Seed yield (t ha -1 ) N uptake (kg ha -1 )
Cultivar N0 N120 N240 N0 N120 N240
Apex 3,02 b 4,26 b 4,63 a 85,3 b 142,8 b 198,5 b
Bristol 2,70 a 4,26 b 4,99 b 73,3 a 129,4 a 193,1 b
Lirajet 2,69 a 3,88 a 4,57 a 75,2 ab 123,4 a 188,9 b
Capitol 2,67 a 3,94 a 4,46 a 74,9 a 122,3 a 171,7 a
F-Test: C:*** N:*** CxN:* C:*** N:*** CxN:*