Enhanced-efficiency fertilizers are not a panacea for resolving the nitrogen problem

Tingyu Li, Weifeng Zhang, Jiao Yin, Yuelai Lu, David Chadwick, Xuejun Liu, Xinping Chen, Fusuo Zhang, David Powlson, David Norse, Zhengxia Dou

Research output: Contribution to journalArticlepeer-review

Abstract

Improving nitrogen (N) management for greater agricultural output while minimizing unintended environmental consequences is critical in the endeavor of feeding the growing population sustainably amid climate change. Enhanced-efficiency fertilizers (EEFs) have been developed to better synchronize fertilizer N release with crop uptake, offering the potential for enhanced N use efficiency (NUE) and reduced losses. Can EEFs play a significant role in helping address the N management challenge? Here we present a comprehensive analysis of worldwide studies published in 1980-2016 evaluating four major types of EEFs (polymer-coated fertilizers PCF, nitrification inhibitors NI, urease inhibitors UI, and double inhibitors DI, i.e. urease and nitrification inhibitors combined) regarding their effectiveness in increasing yield and NUE and reducing N losses. Overall productivity and environmental efficacy depended on the combination of EEF type and cropping systems, further affected by biophysical conditions. Best scenarios include: (i) DI used in grassland (n = 133), averaging 11% yield increase, 33% NUE improvement, and 47% decrease in aggregated N loss (sum of NO3- , NH3 , and N2 O, totaling 84 kg N/ha); (ii) UI in rice-paddy systems (n = 100), with 9% yield increase, 29% NUE improvement, and 41% N-loss reduction (16 kg N/ha). EEF efficacies in wheat and maize systems were more complicated and generally less effective. In-depth analysis indicated that the potential benefits of EEFs might be best achieved when a need is created, for example, by downward adjusting N application from conventional rate. We conclude that EEFs can play a significant role in sustainable agricultural production but their prudent use requires firstly eliminating any fertilizer mismanagement plus the implementation of knowledge-based N management practices.
Original languageEnglish
Pages (from-to)e511-e521
Number of pages11
JournalGlobal Change Biology
Volume24
Issue number2
Early online date3 Oct 2017
DOIs
Publication statusPublished - 1 Feb 2018

Keywords

  • ammonia loss
  • biophysical conditions
  • enhanced efficiency fertilizers
  • nitrate leaching

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