Optimizing rice yield, quality and nutrient use efficiency through combined application of nitrogen and potassium

Guangyi Chen; Qiang Duan; Chaoyue Wu; Xingmei He; Mingming Hu; Congmei Li; Yuyuan Ouyang; Ligong Peng; Hong Yang; Qiuqiu Zhang; Qinggui Jiang; Yan Lan; Tian Li

doi:10.3389/fpls.2024.1335744

Optimizing rice yield, quality and nutrient use efficiency through combined application of nitrogen and potassium

Front Plant Sci. 2024 Mar 11:15:1335744. doi: 10.3389/fpls.2024.1335744. eCollection 2024.

Authors

Guangyi Chen^#¹, Qiang Duan^#^{1

2}, Chaoyue Wu¹, Xingmei He¹, Mingming Hu³, Congmei Li³, Yuyuan Ouyang^{1

4}, Ligong Peng¹, Hong Yang¹, Qiuqiu Zhang¹, Qinggui Jiang⁵, Yan Lan⁶, Tian Li¹

Affiliations

¹ College of Agronomy, Sichuan Agricultural University, Chengdu, China.
² Station of Seed Management, Agricultural and Rural Bureau of Xuanhan County, Dazhou, China.
³ Rice Research Institute, Sichuan Agricultural University, Chengdu, China.
⁴ Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China.
⁵ Station of Foundation and Improved Seed-breeding, Sichuan Provincial Department of Agriculture and Rural Affairs, Chengdu, China.
⁶ College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China.

^# Contributed equally.

Abstract

Reasonable nitrogen (N) and potassium (K) application rates can effectively improve fertilizer use efficiency, rice yield and quality. A two-year field experiment was conducted with combined application of three N rates (135, 180, and 225 kg ha^-1, denoted as N1-N3) and four K rates (0, 90, 135, and 180 kg ha^-1, denoted as K0-K3) using super indica hybrid rice cultivar Yixiangyou (YXY) 2115 to explore the effects of co-application of N and K on rice growth and development. The results indicated that the combined application of N and K had significantly interactive effects on dry matter (DM) accumulation, nutrients absorption, N harvest index (NHI), K harvest index (KHI), spikelets per panicle and most rice quality indexes. The highest total DM accumulation (17998.17-19432.47 kg ha^-1) at maturity stage was obtained under N3K2. The effect of co-application of N and K on nutrients absorption and utilization varied between the two years and within each year. The highest total N and K accumulations at maturity stage were observed under N3K1 and N3K2, respectively, while the highest N recovery efficiency (NRE) and K recovery efficiency (KRE) were observed under N1K3. High expression levels of N and K metabolism-related genes in rice grains were observed under N3K2 or N3K3, consistent with N and K uptake. Co-application of N and K increased rice yield significantly and the highest yield (6745.02-7010.27 kg ha^-1) was obtained under N2K2. As more N was gradually applied, rice appearance quality improved but milling, cooking and eating quality decreased. Although appropriate application of K could improve rice milling, cooking and eating quality, it reduced appearance quality. The optimal milling, cooking and eating quality were obtained under N1K2, while the best appearance quality was obtained under N3K0. Overall, a combination of 135-210 kg ha^-1 N and 115-137 kg ha^-1 K application rates was recommended for achieving relatively higher yield and better quality in rice production.

Keywords: combined application of nitrogen and potassium; nutrient absorption-utilization; quality; rice; yield.

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 funds from the Sichuan Science and Technology Program, China (2021YFYZ0020 and 2022YFH0029).