Nitrogen Use Efficiency of Spring Wheat Genotypes under Field and Lysimeter Conditions

Lysimeters and neighbouring fields were used from 1998 to 2000 to assess parameters of N use efficiency of three Swiss spring wheat (Triticum aestivum L.) genotypes. An old (Albis), a new (Toronit) and an experimental genotype (L94491) were compared with no and ample (250 kg N ha^?1) N fertilizer supply. N fertilization increased biomass, grain yield and grain N concentration of all genotypes in all years and in both testing systems (field, lysimeters) but only a few genotype × N interactions were observed. Generally, Toronit was superior in producing biomass and grain yield and L94491 in accumulating N in the grain resulting in identical N biomass yields. Albis showed the lowest and Toronit the highest fertilizer recovery, irrespective of the method of calculation (¹⁵N or difference method). The medium yielding L94491 recovered similar amounts of fertilizer N as Toronit, mainly due to the high N concentration in the biomass. The ranking of the genotypes for the investigated traits was similar in both testing systems and results comparable with those reported in the literature, indicating that the lysimeter facility is suitable for investigations of agronomic traits on soil–plant relationships, where a constant recording of the soil properties is required.