Improving Nitrogen Use Efficiency in Rice for Sustainable Agriculture: Strategies and Future Perspectives

Abstract

Nitrogen (N) is an important nutrient for the growth and development of rice. The application of N fertilizer has become one of the inevitable ways to increase rice yield due to insufficient soil N content. However, in order to achieve stable and high yield, farmers usually increase N fertilizer input without hesitation, resulting in a series of problems such as environmental pollution, energy waste and low production efficiency. For sustainable agriculture, improving the nitrogen use efficiency (NUE) to decrease N fertilizer input is imperative. In the present review, we firstly demonstrate the role of N in mediating root architecture, photosynthesis, metabolic balance, and yield components in rice. Furthermore, we further summarize the current agronomic practices for enhancing rice NUE, including balanced fertilization, the use of nitrification inhibitors and slow-release N fertilizers, the split application of N fertilizer, root zone fertilization, and so on. Finally, we discuss the recent advances of N efficiency-related genes with potential breeding value. These genes will contribute to improving the N uptake, maintain the N metabolism balance, and enhance the NUE, thereby breeding new varieties against low N tolerance to improve the rice yield and quality. Moreover, N-efficient varieties also need combine with precise N fertilizer management and advanced cultivation techniques to realize the maximum exploitation of their biological potential.

Rice (Oryza sativa L.) Growth and Yield Responses to Yara Fertilizer Formulations in Rain-fed Lowland Condition

“…The highest height obtained by UNIK-15 at 125 kg ha -1 +URE at 125 kg ha -1 could be attributed to the adequate N provision and its efficiency in enhancing crop metabolism. Fertilizer N efficiency in lowland rice can be enhanced by right application timing and placement to correspond with crop peak requirements [33,6]. The higher nitrogen supply from urea (46% N) over Amidas (40% N), possibly increased plants physiological processes, and the underlying cause of the higher performance of UNIK-15+URE and ACT+URE over UNIK-15+ AMI and ACT+AMI.…”

Promising physiological traits associated with nitrogen use efficiency in rice under reduced N application

“…Nitrogen (N) is an essential nutrient for the growth, development, and maintenance of rice ( Wang et al., 2022 ). As soil N fertilizer alone is not adequate for increase in rice production, farmers add higher amounts of N fertilizer expecting that increased application of N fertilizer will result in the enhanced yields ( West et al., 2014 ; Wang et al., 2022 ). Higher N fertilizer inputs are leading to serious environmental problems and low production efficiency ( Wang et al., 2022 ).…”

“…As soil N fertilizer alone is not adequate for increase in rice production, farmers add higher amounts of N fertilizer expecting that increased application of N fertilizer will result in the enhanced yields ( West et al., 2014 ; Wang et al., 2022 ). Higher N fertilizer inputs are leading to serious environmental problems and low production efficiency ( Wang et al., 2022 ). As only 30 to 50% of applied N is reported to be utilized by rice, reduction of N fertilizer application by 50% of the recommended N was chosen as the current target for NUE in rice ( Ladha et al., 2020 ).…”

“…However, soil N content in agricultural land cannot sustain the higher yields of improved rice varieties. Hence, the application of N fertilizer has become unavoidable to enhance rice yield ( Wang et al., 2022 ). However, most of the fertilizers applied in agriculture is the main source of environmental losses of reactive N compounds contributing to N pollution globally ( Sutton et al., 2013 ) as well as in South Asia ( Raghuram et al., 2021 ).…”

Rice yield in Costa Rican Central Pacific did not improve with a urease inhibitor

“…The increase in NUE in grain during the dry season observed in La Bandera is attributed to the reduction under favorable conditions of NH 3 -N volatilization (Santos et al, 2023), and the translocation of N from foliage to grain. It is well-documented that enhancing the N utilization in stages preceding floral differentiation in rice contributes to approximately 50% of the final grain content (Wang et al, 2022). In the case of experiment in Barbudal conducted during the rainy season, C/N ratio of less than 7.5 suggests that N is readily available to the rice, and accordingly, most N is likely taken up from the soil, rather than from fertilizer.…”