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Research article - Peer-reviewed, 2022

Is the NH4+-induced growth inhibition caused by the NH4+ form of the nitrogen source or by soil acidification?

Wang, Feng; Wang, Qiang; Yu, Qiaogang; Ye, Jing; Gao, Jingwen; Liu, Haitian; Yong, Jean W. H.; Yu, Yijun; Liu, Xiaoxia; Kong, Haimin; He, Xinhua; Ma, Junwei


Soil acidification often occurs when the concentration of ammonium (NH4+) in soil rises, such as that observed in farmland. Both soil acidification and excess NH4+ have serious adverse effects on crop growth and food production. However, we still do not know which of these two inhibitors has a greater impact on the growth of crops, and the degree of their inhibitory effect on crop growth have not been accurately evaluated. 31 wheat cultivars originating in various areas of China were planted under 5 mM sole NH4+ (ammonium nitrogen, AN) or nitrate nitrogen in combined with two pH levels resembling acidified conditions (5.0 and 6.5). The results showed that the shoots and roots biomass were severely reduced by AN in both and these reduction effects were strengthened by a low medium pH. The concentration of free NH4+ and amino acids, the glutamine synthetase activity were significantly higher, but the total soluble sugar content was reduced under NH4+ conditions, and the glutamine synthetase activity was reduced by a low medium pH. Cultivar variance was responsible for the largest proportion of the total variance in plant dry weight, leaf area, nodal root number, total root length and root volume; the nitrogen (N) form explains most of the variation in N and C metabolism; the effects of pH were the greatest for plant height and root average diameter. So, soil acidification and excess NH4+ would cause different degrees of inhibition effects on different plant tissues. The findings are expected to be useful for applying effective strategies for reducing NH4+ stress in the field.


soil acidification; ammonium stress; nitrogen assimilation; wheat growth; natural variation

Published in

Frontiers in Plant Science
2022, volume: 13, article number: 968707

Authors' information

Wang, Feng
Zhejiang Academy of Agricultural Sciences
Wang, Qiang
Zhejiang Academy of Agricultural Sciences
Yu, Qiaogang
Zhejiang Academy of Agricultural Sciences
Ye, Jing
Zhejiang Academy of Agricultural Sciences
Gao, Jingwen
Zhejiang Academy of Agricultural Sciences
Liu, Haitian
Zhejiang Academy of Agricultural Sciences
Yong, Jean W. H. (Yong, Jean W.H)
University of Western Australia
Swedish University of Agricultural Sciences, Department of Biosystems and Technology
He, Xinhua
University of Western Australia
He, Xinhua
Southwest University - China
Ma, Junwei
Zhejiang Academy of Agricultural Sciences
Yu, Yijun
Arable Soil Qual and Fertilizer Adm Stn Zhejiang Pro

Sustainable Development Goals

SDG2 Zero hunger

UKÄ Subject classification

Soil Science
Agricultural Science

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