3.6. Grain yield and N utilization efficiency
In both years, wheat grain yields and N utilization efficiencies had the same tendency (Table 5).
Grain yield increased as total N rate increased, but showed no significant difference when N rate exceeded 210 kg hm−2, and even decreased.
At the same N rate, grain yield was highest for the N210(5/5) treatment.
N agronomy efficiency (NAE) and apparent N recovery efficiency (NRE) decreased as N rate increased, and the treatment N210(5/5) yielded the best response.