TY - JOUR
T1 - Nitrogen application rates need to be reduced for half of the rice paddy fields in China
AU - Zhang, Dan
AU - Wang, Hongyuan
AU - Pan, Junting
AU - Luo, Jiafa
AU - Liu, Jian
AU - Gu, Baojing
AU - Liu, Shen
AU - Zhai, Limei
AU - Lindsey, Stuart
AU - Zhang, Yitao
AU - Lei, Qiuliang
AU - Wu, Shuxia
AU - Smith, Pete
AU - Liu, Hongbin
N1 - This research was partially supported by the National Key Research and Development Program (2016YFD0800500), the Special Fund for Agro-scientific Research in the Public Interest (201003014, 201303089), National Natural Science Foundation of China (41773068) and the Newton Fund (Grant Ref: BB/N013484/1).
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Increasing nitrogen (N) application to croplands in order to support growing food demand is a major cause of environmental degradation. However, evaluations of suitable N application rates based on environmental benefit have rarely been carried out for paddy-rice at a national scale in China. To address this challenge, we investigated the current status of N management in 1531 counties, covering the primary agro-ecological regions of Chinese rice production in 2008, and conducted 12 field experiments with six N level practices for 3 years (2011–2013). Results showed that the highest yields for rice were 5.8–8.6 Mg ha−1 with N rates of 209.4–289.8 kg N ha−1. Compared with the N rate for the highest yield (YHN), the environmentally optimal N rate (EnON) was lower by 20–39% and the corresponding N loss was reduced by 21–45%, while ensuring 95–99% of the highest crop yield. In China, the N inputs to paddy fields exceeded the YHN and EnON rates by 10% and 45%, respectively. After adjusting the N rate to paddy fields to the EnON rate, the N amount used in China and the corresponding N lost would be reduced by 0.9 and 0.5 Tg N yr−1, respectively, which enable highly efficient production of food with the lowest N loss possible. Thus, we suggest that N use rates for 45% of rice paddy fields in China, for which N application rates exceed the EnON rate, need to be reduced to mitigate environmental damage, and this can be done while still meeting China's food demand.
AB - Increasing nitrogen (N) application to croplands in order to support growing food demand is a major cause of environmental degradation. However, evaluations of suitable N application rates based on environmental benefit have rarely been carried out for paddy-rice at a national scale in China. To address this challenge, we investigated the current status of N management in 1531 counties, covering the primary agro-ecological regions of Chinese rice production in 2008, and conducted 12 field experiments with six N level practices for 3 years (2011–2013). Results showed that the highest yields for rice were 5.8–8.6 Mg ha−1 with N rates of 209.4–289.8 kg N ha−1. Compared with the N rate for the highest yield (YHN), the environmentally optimal N rate (EnON) was lower by 20–39% and the corresponding N loss was reduced by 21–45%, while ensuring 95–99% of the highest crop yield. In China, the N inputs to paddy fields exceeded the YHN and EnON rates by 10% and 45%, respectively. After adjusting the N rate to paddy fields to the EnON rate, the N amount used in China and the corresponding N lost would be reduced by 0.9 and 0.5 Tg N yr−1, respectively, which enable highly efficient production of food with the lowest N loss possible. Thus, we suggest that N use rates for 45% of rice paddy fields in China, for which N application rates exceed the EnON rate, need to be reduced to mitigate environmental damage, and this can be done while still meeting China's food demand.
KW - Crop yield
KW - Environmental benefit
KW - Food security
KW - Nitrogen loss
KW - Nitrogen rate threshold
KW - Non-point source pollution
UR - http://www.scopus.com/inward/record.url?scp=85048513853&partnerID=8YFLogxK
U2 - 10.1016/j.agee.2018.05.023
DO - 10.1016/j.agee.2018.05.023
M3 - Article
AN - SCOPUS:85048513853
VL - 265
SP - 8
EP - 14
JO - Agriculture Ecosystems & Environment
JF - Agriculture Ecosystems & Environment
SN - 0167-8809
ER -