The N uptake rate in our maize plants (Table 3) was similar to
the rates reported in other studies, i.e. 155e300 kg N ha1 [6,45].
The higher uptake rate at higher doses of N suggested some degree
of ‘luxury consumption’, but it was observed no differences in the
biomass of mature plants treated with PS45 and N300 (Table 3).
This could reflect experimental error because the area used for
biomass sampling in each plot was smaller (3m2) compared to that
assessed for grain production