One-time fertilization of controlled-release urea with compound fertilizer and rapeseed cake maintains rice grain yield and improves nitrogen use efficiency under reduced nitrogen conditions

Yajie Hu; Qin Cai; Yi Xu; Jiantao Xue; Enwei Yu; Haiyan Wei; Ke Xu; Zhongyang Huo; Hongcheng Zhang

doi:10.3389/fpls.2023.1281309

One-time fertilization of controlled-release urea with compound fertilizer and rapeseed cake maintains rice grain yield and improves nitrogen use efficiency under reduced nitrogen conditions

Front Plant Sci. 2023 Oct 10:14:1281309. doi: 10.3389/fpls.2023.1281309. eCollection 2023.

Authors

Yajie Hu¹, Qin Cai¹, Yi Xu¹, Jiantao Xue¹, Enwei Yu¹, Haiyan Wei¹, Ke Xu¹, Zhongyang Huo¹, Hongcheng Zhang¹

Affiliation

¹ Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.

Abstract

Nitrogen (N) rate reduction and simplified fertilization can mitigate environmental impacts and reduce the involvement of manual labor in rice (Oryza sativa L.) production. Controlled-release urea (CRU) has been recommended as an effective alternative technique to conventional urea fertilization, and it can improve rice yield and N use efficiency (NUE) and reduce labor costs. However, the information on the effects of one-time fertilization with CRU on maintaining yield and improving NUE under reduced chemical N conditions is limited. In this study, controlled-release bulk blending fertilizer (CRF), consisting of CRU with release periods of 40 and 100 days, mixed with compound fertilizer, was applied as basal fertilizer. Increased ~20% plant density (ID) and rapeseed cake fertilizer (RC, increase 20% organic N) were combined with CRF, respectively. The N treatments with 20% chemical N reduction were as follows: reduced N fertilizer (RNF), CRF, CRF+ID, and CRF+RC. In addition, a conventional split fertilizer application with 300 kg ha^-1 N was applied as the control (CK). Rice yield and its components, dry matter accumulation, N uptake, and NUE were investigated to evaluate whether one-time N fertilization realized stable yield and high NUE under reduced 20% chemical N conditions. Compared with CK, the CRF+RC treatment exhibited a comparable grain yield, while the other reduced N treatments (RNF, CRF, and CRF+ID) had a lower grain yield. Moreover, CRF+ID exhibited a higher rice grain yield than RNF or CRF under the same N level. Irrespective of exogenous organic N, CRF+RC exhibited significantly higher NUE than CK. The CRF+ID treatment showed a significantly higher N partial factor productivity (PFN) than CK but comparable N agronomic efficiency (NAE) and N recovery efficiency (NRE). Therefore, a one-time fertilizer application of CRF+RC maintained grain yield and improved the NUE while reducing the N rate and fertilization times, demonstrating its potential application in rice production.

Keywords: grain yield; nitrogen use efficiency; one-time fertilization; reduced nitrogen; rice.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants from the National Key Research Program of China (2017YFD0301205), and Yangzhou University “qinglan project”, and the Earmarked Fund for Jiangsu Agriculture Industry Technology System (JATS [2022]485), and the Priority Academic Program Development of Jiangsu Higher Education Institutions.