Abstract
Although nitrogen (N), phosphorus (P), and potassium (K) co-application improves crop growth, yield, and N use efficiency (NUE) of rice, few studies have investigated the mechanisms underlying these interactions. To investigate root morphological and physiological characteristics and determine yield and nitrogen use parameters, rhizo-box experiments were performed on rice using six treatments (no fertilizer, PK, N, NK, NP, and NPK) and plants were harvested at maturity. The aboveground biomass at the elongating stage and grain yield at maturity for NPK treatment were higher than the sum of PK and N treatments. N, P, and K interactions enhanced grain yield due to an increase in agronomic N use efficiency (NAE). The co-application of N, P, and K improved N uptake and N recovery efficiency, exceeding the decreases in physiological and internal NUE and thereby improving NAE. Increases in root length and biomass, N uptake per unit root length/root biomass, root oxidation activity, total roots absorption area, and roots active absorption area at the elongating stage improved N uptake via N, P, and K interactions. The higher total N uptake from N, P, and K interactions was due to improved root characteristics, which enhanced the rice yield and NUE.
Highlights
Nitrogen (N) is an elementary mineral nutrient required for plant growth and is widely applied in crop production [1]
Compared to other fertilizer combinations, plants exposed to N, P, and K showed decreased NPE and N use efficiency (NIE), but improved N fertilizer (NRE), which overrode the reduction in the yield produced per absorbed N, effectively explaining the increase in NAE
Increases in root length and biomass in the 0–20 cm of the soil profile, N uptake per unit root length, N uptake per unit root biomass, root oxidation activity, total root absorption area, and root active absorption area at the elongating stage were responsible for the improved total N uptake due to N, P, and K interactions
Summary
Nitrogen (N) is an elementary mineral nutrient required for plant growth and is widely applied in crop production [1]. Crops commonly use less than 40% of the N fertilizers in the application year [3], and the recovery of N ranges from 30% to 50% [4]. Unreasonable fertilization management decreases N use efficiency (NUE) and enhances production costs and environmental risks [5]. Improving NUE is crucial to reduce economic cost and environmental impact while maintaining crop yield. Godfrey et al reported that N recovery efficiency can increase up to 70% by optimizing fertilizer and crop management and providing suitable environmental conditions [9]. Balanced fertilizer application is the most crucial component of modern crop production technologies [10]. The mechanisms underlying the interactions regarding the efficient utilization of N fertilizer by crops requires specific investigation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
