A Roadmap for Lowering Crop Nitrogen Requirement. (October 2019)

• Record Type: Journal Article
• Authors: Swarbreck, Stéphanie M.; Wang, Meng; Wang, Yuan; Kindred, Daniel; Sylvester-Bradley, Roger; Shi, Weiming; Varinderpal-Singh, ; Bentley, Alison R.; Griffiths, Howard
• Is Part Of: Trends in plant science. Volume 24:Number 10(2019)
• Page Start: 892
• Page End: 904
• Publication Date: 2019-10
• Subjects: nitrogen -- wheat -- yield -- nitrogen use efficiency -- response -- nitrogen demand; Botany -- Periodicals; Botanique -- Périodiques; Botany; Periodicals; 580.5
• DOI: 10.1016/j.tplants.2019.06.006
• Languages: English
• ISSNs: 1360-1385

Abstract

Abstract : Increasing nitrogen fertilizer applications have sustained a growing world population in the 20th century. However, to avoid any further associated environmental damage, new sustainable agronomic practices together with new cultivars must be developed. To date the concept of nitrogen use efficiency (NUE) has been useful in quantifying the processes of nitrogen uptake and utilization, but we propose a shift in focus to consider nitrogen responsiveness as a more appropriate trait to select varieties with lower nitrogen requirements. We provide a roadmap to integrate the regulation of nitrogen uptake and assimilation into varietal selection and crop breeding programs. The overall goal is to reduce nitrogen inputs by farmers growing crops in contrasting cropping systems around the world, while sustaining yields and reducing greenhouse gas (GHG) emissions. Highlights: Current practice for managing nitrogen (N) use for cereal production are not environmentally sustainable. Overuse of N fertilizers is a global problem for millions of farmers who must decide on N applications whether, when and how much. A combination of improved advice on N management for specific cropping regimes is required, together with a breeding target of new commercial crop varieties with sustainable yields and a low N requirement. While N use efficiency (NUE) has been a useful concept for quantifying the genetic differences in N uptake and utilization, the concept of an economic N optimum derived from N yield dose–response curves may provide new insights for lowering the N requirement.