Grain yield, plant nitrogen content and nitrogen use efficiency as affected by controlled-release urea and straw biochar in a rice field

Abstract

Resulting from the positive effect on rice productivity, the application of biochar and controlled-release urea in the form of polymer-coated urea (PCU) in crop production attracts more and more interest. However, field studies considering the combined effect of biochar and PCU are rare. This 2-year study examined the combined effects of biochar and PCU on yield, yield components, plant height, plant nitrogen concentration and nitrogen recovery efficiency in a waterlogged rice field. Experimental treatments combined two biochar rates (0 and 2800 kg ha⁻¹) and three nitrogen rates (0, 120 and 180 kg N ha⁻¹). The results showed a yield decrease under biochar application without nitrogen fertilizer. The application of 120 kg N ha⁻¹ PCU and biochar had the highest yield in 2017. No significant differences of grain yields were indicated between 120 and 180 kg N ha⁻¹. High grain yield and nitrogen use efficiency was obtained with 120 kg N ha⁻¹ PCU. Therefore, 120 kg N ha⁻¹ PCU can be recommended for rice production in this area.

Keywords:

• coated urea
• fertilizer
• nitrogen use efficiency
• super hybrids

Acknowledgments

We thank Mrs Shuiying Xu and Mr Zhongmao Yang for the help on field management. We also thank Ziwei Xie, Yuanbo Cui, Xueyan Wang, Yiran Song, Jiayu Hu, Xiaomin Wang, and Jiaxin Wang for their assistance on measurement. All the authors also thank Mr. Longping Yuan, the father of hybrid rice in China, who died on May 22, 2021, for his outstanding contribution to world food security. The authors are also grateful to anonymous referees for peer review and giving useful comments on the manuscript.

Conflict of interest

The authors declare that they have no conflicts of interests.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was finically supported by the Science and Technology Research Project of Jiangxi Provincial Education Department (GJJ170941, GJJ180871), Basic scientific research projects in Wenzhou (N2020002), Open project of Key Laboratory of crop breeding in southern Zhejiang province (2021SZCB02) and CSC scholar-ship to Xin Yang (201908360107). Stephan M. Haefele at Rothamsted Research was partially funded by an Institute Strategic Programme (ISP) grant, ‘Soils to Nutrition’ (S2N) grant number BBS/E/C/000I0310.