Yield, dry matter and N characteristics in canola as affected by fertilizer N rate and split-application ratio under high soil fertility condition

Abstract

The effects on seed yield, dry matter and nitrogen (N) characteristics under two fertilizer N rates of 240 and 270 kg ha⁻¹ and three N split-application ratios (SAR) of basal: bolting fertilizer 7:3, 6:4 and 5:5 were investigated. Under 240 kg N ha⁻¹ condition, seed yield was positively correlated with the number of effective pods (r = 0.90**), which was the main determinant of seed yield. Under 270 kg N ha⁻¹ condition, seed yield was closely related to 1000-seed weight (r = 0.97**) and the number of seeds per pod (r = 0.90**), with the former appeared to be the most important determinant. The yields and numbers of effective pods in the N SAR 6:4 with N rate of 240 kg ha⁻¹ were the highest among three SARs, while the yields of N SAR 5:5 under 270 kg N ha⁻¹ were the lowest, attributable to the high lodging angle, low 1000-seed weight and low number of seeds per pod. Under 240 kg N ha⁻¹ condition, the biomass, root dry weight, ratio of root to shoot, harvest index (HI), total N accumulation, N harvest index (NHI)and N utilization efficiency for grain yield (NUEg)in the N SAR 6:4 were the greatest among different SARs. The study revealed that, to achieve stable and high yields of winter canola, N recommendation at a rate of 240 kg ha⁻¹ and N SAR 6:4 was suggested in this high soil fertility region.

Keywords:

• canola
• dry matter and N characteristics
• N rate
• N split-application ratio
• yield

Acknowledgments

We gratefully thank our lab staffs for their helps in determination and analysis of samples.

Additional information

Funding

This work was financially supported by the National Key Research and Development Program of China (2018YFD0200905), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).