Open AccessNitrogen/potassium interactions increase rice yield by improving canopy performance
Author(s) -
Ye Tinghong,
Zhang Jianglin,
Li Jing,
Lu Jianwei,
Ren Tao,
Cong Rihuan,
Lu Zhifeng,
Li Xiaokun
Publication year - 2021
Publication title -
food and energy security
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.253
H-Index - 25
ISSN - 2048-3694
DOI - 10.1002/fes3.295
Subject(s) - canopy , nitrogen , interception , potassium , nutrient , photosynthesis , yield (engineering) , field experiment , grain yield , agronomy , biomass (ecology) , chemistry , mathematics , botany , biology , physics , ecology , organic chemistry , thermodynamics
The interactions between nitrogen (N) and potassium (K) are important determinants of rice yield, but the mechanisms involved remain poorly understood. For example, N/K interactions may influence light utilization and N distribution in the canopy. Field experiments were therefore performed to resolve this issue, using factorial combination of N and K. The interaction between N and K had a significant effect on the grain yield, N uptake, and the NUE of grain production (NUEg), and biomass production (NUEb). The application of either N or K alone resulted in lower yields than the combined application of these nutrients. The combined application of N and K increased rice yields by 54.5% in 2018 and by 76.1% in 2019, compared with N0K0. Similarly, N uptake, NUEg, and NUEb were higher when N was supplied with K than with N application alone. The higher grain yields, N uptake rates, and NUEs observed with the combined N and K treatment were attributed to the following: (1) a higher leaf area index that resulted in better light interception; (2) improved the coordination of light and N distribution within the canopy. Evidence for improved light use by photosynthesis is provided by the observed lower light extinction coefficient ( K L ), the higher specific leaf N in the top leaves (SLN o ), higher extinction coefficients for effective leaf N ( K N ) and K N / K L values. We conclude that the interactions between N and K support higher yields by improving canopy performance even at lower N rates.