A review of nitrogen translocation and nitrogen-use efficiency

Abstract

Nitrogen (N) is a primary nutrient for crop growth. In most agricultural areas, crop production relies heavily on the supply of exogenous N fertilizers. Globally, a large amount of nitrogenous fertilizer is applied to achieve maximum crop productivity. However, N fertilizer application is costly and negatively impacts the environment. One way around these problems is to provide a new N-use efficiency (NUE) framework that promotes the efficient acquisition and use of N and high N translocation rates from vegetative organs to reproductive organs under reduced N inputs. This review integrates the current knowledge about the direct and indirect effects of soil properties, crop varieties, soil water status, soil N fertilizers, and soil microbes on N translocation. In addition, we explore strategies that specifically accomplish N translocation via mycorrhizal fungi. Finally, we discuss recent advances in plant physiology, demonstrating that N translocation is an effective target to improve cereal yields and NUE. Although the relationship between crop variety and N translocation is mostly unknown, understanding this relationship is necessary to select and breed crop varieties that exhibit high yields and N translocation efficiency.

Keywords:

• crop growth
• crop yield
• nitrogen use efficiency
• nitrogen fertilizer

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This study was funded by the National Key Research and Development Program of China (Grant No. 2017YFC0504704) and the National Natural Science Foundation of China (51669034, 51809224), Shaanxi Innovation Talent Promotion Program - Young Science and Technology Star Project (2018KJXX-080) and Key Scientific Research Program of Education Department of Shaanxi Province (18JS117).