World Cereal Nitrogen Use Efficiency Trends: Review and Current Knowledge
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Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
Agrosystems, Geosciences & Environment
Abstract
Two decades ago, world cereal nitrogen use efficiency (NUE) was documented at 33%. Since then,
research addressing NUE has advanced. However, there are no current estimates to communicate
whether or not research efforts and recent advances have contributed to improved NUE. With the
apparent trends for increasing greenhouse gases, NUE values could be used as a management tool
for agronomic and environmental sustainability. Our objective was to provide current estimates and
trends of NUE for the world and selected countries for cereal crops cultivated in relatively large
quantities. Data from the Food and Agriculture Organization (www.fao.org/faostat) website were
used to compute NUE. The difference method was employed to derive NUE and trends. Results
indicated that cereal NUE in 2015 was 35, 41, 30, and 21% for the world, the United States, China,
and India, respectively. Compared with 33% reported in 1999, there was insignificant trend of
increase (r2 = 0.01) from 2002 to 2015 for cereal world NUE (p > 0.05). Low NUE for China and
India was due to high N consumption. A slight improvement for the United States from 31% in
2002 to 41% in 2015 (r2 = 0.20) could be a result of using improved cultivars and precision crop
management. Increasing cereal NUE in the United States echoes the value of new technologies and
the heightened importance of the environment. Recognizing year-to-year variability in N fertilizer
requirement and implementing a systematic approach that combines agronomic recommendations
with improved crop varieties could further improve NUE.
Description
Keywords
World Cereal Nitrogen, Efficiency, Knowledge
Citation
Omara, P., Aula, L., Oyebiyi, F., & Raun, W. R. (2019). World cereal nitrogen use efficiency trends: review and current knowledge. Agrosystems, Geosciences & Environment, 2(1), 1-8. doi:10.2134/age2018.10.0045