The objective of this study was to
investigate the nitrogen use
efficiency of various wheat varieties and to establish evaluation
indicators for nitrogen efficient use in wheat, thereby providing
both theoretical reference and a practical basis. The experiment was
conducted at Jiaozhou Modern Agriculture Demonstration Park of Qingdao
Agricultural University (35.53°N, 119.58°E) from October
2021 to June 2023. Twenty-six main wheat varieties in the North China
Plain were used as test materials. Four nitrogen fertilizer levels
of 0, 150, 210, and 270 kg/hm2 were set up. The nitrogen
fertilizer level was the main factor, and the variety was the secondary
factor. According to the yield and nitrogen accumulation of each variety
under different nitrogen fertilizer levels, cluster analysis was carried
out, respectively. It was found that Zhongmai 578 (H1), Zhongmai 175
(H2), and Weimai 8 (H3) had a higher yield under four nitrogen fertilizer
levels. These varieties were nitrogen efficient, and their nitrogen
accumulation was also higher. On the other hand, Jingshuang 16 (L1),
Nongda 212 (L2), and Beijing 841 (L3) had lower yields under four
nitrogen fertilizer levels. These varieties were nitrogen inefficient,
and their nitrogen accumulation was also lower. The other 20 varieties
had a medium yield and medium nitrogen accumulation. In this study,
the differences of nitrogen use efficiency, nitrogen harvest index,
nitrogen agronomic efficiency, and nitrogen partial factor productivity
between three nitrogen efficient varieties and three nitrogen inefficient
varieties were analyzed.