Interactive effects of sowing pattern and planting density on grain yield and nitrogen use efficiency in large spike wheat cultivar

Abstract

In order to find out the way to achieve further improvement in the grain yield (GY) and nitrogen use efficiency (NUE) of winter wheat, two sowing pattern (the wide range sowing and conventional drilling sowing) and seven planting densities (130×104, 200×104, 270×104, 340×104, 410×104, 480×104, and 550×104 plants hm–2) were designed during 2015–2016 and 2016–2017 growing seasons. Tainong 18, a winter wheat cultivar with larger spike and lower tillering capacity, was used to investigate the combined effects of sowing pattern and planting density on GY and NUE. Compared with the conventional drilling sowing, the wide range sowing with higher planting density effectively alleviated the negative effect of increasing spikes per unit area and nitrogen uptake efficiency (NUpE) on decreasing single spike weight and nitrogen utilization efficiency (NUtE), respectively. Concurrent improvement in GY and NUE was achieved by increasing the number of spikes per unit area and NUpE. The planting density resulting in the highest GY and NUE under wide range sowing conditions was 410×104 plants hm–2, which was significantly higher than that (340×104 plants hm–2) under conventional drilling sowing. Moreover, the increase percentage of GY and NUE under wide ranging sowing was also significantly higher than that under drilling sowing. In summary, it is feasible to further improve GY and NUE of large spike wheat cultivar through rational combination of wide range sowing with higher planting density. Under the condition of this experiment, the optimal combination measure for high GY and NUE was sowing width of 8–10 cm with plant density of 410×104 plants hm–2.