Book Description

The predominant role of unused fertilizers in reactive nitrogen pollution and the need for research and policies to improve nitrogen use efficiency (NUE) is now well known globally. NUE research was originally championed by the scientists of the International Nitrogen Initiative (INI) and later recognized by some national governments and UN agencies such as UNEP, FAO and UNECE. The resulting first ever UN resolution on “Sustainable nitrogen management” in 2019 boosted the demand for solutions, especially in agriculture. The Berlin Declaration from the INI 2021 conference called for improvement of nitrogen use efficiency towards achieving sustainable food systems and all the 17 sustainable development goals. Crop NUE is primarily a biological problem, as there exists a genetic limit to agronomic improvement. Overcoming this genetic barrier for crop improvement requires better understanding of the biological mechanisms of N-response and the genetic determinants of NUE. Fortunately, crop genomics in general and the functional genomics of N-response in particular have been providing a wealth of information. The recent developments in phenotyping and genotyping for NUE and the emergence of phenomics, coupled with the growing ability of bioinformatics to integrate diverse datasets offer unprecedented opportunities to solve the NUE puzzle. Some candidate genes for this multi-genic trait have been validated, while some others are being identified, shortlisted or offered for validation.