Effects of nitrogen application on winter wheat growth, water use, and yield under different shallow groundwater depths

Yingjun She; Ping Li; Xuebin Qi; Shafeeq Ur Rahman; Wei Guo

doi:10.3389/fpls.2023.1114611

Effects of nitrogen application on winter wheat growth, water use, and yield under different shallow groundwater depths

Front Plant Sci. 2023 Mar 7:14:1114611. doi: 10.3389/fpls.2023.1114611. eCollection 2023.

Authors

Yingjun She^{1

2}, Ping Li^{1

3}, Xuebin Qi^{1

3}, Shafeeq Ur Rahman^{4

5}, Wei Guo^{1

3}

Affiliations

¹ Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan, China.
² Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
³ Water Environment Factor Risk Assessment Laboratory of Agricultural Products Quality and Safety, Ministry of Agriculture and Rural Affairs, Xinxiang, Henan, China.
⁴ School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, Guangdong, China.
⁵ Ministry of Education (MOE) Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, China.

Abstract

Shallow groundwater plays a vital role in physiology morphological attributes, water use, and yield production of winter wheat, but little is known of its interaction with nitrogen (N) application. We aimed to explore the effects of N fertilization rate and shallow groundwater table depth (WTD) on winter wheat growth attributes, yield, and water use. Experiments were carried out in micro-lysimeters at WTD of 0.6, 0.9, 1.2, and 1.5 m with 0, 150, 240, and 300 kg/ha N application levels for the winter wheat (Triticum aestivum L.). The results showed that there was an optimum groundwater table depth (Op-wtd), in which the growth attributes, groundwater consumption (GC), yield, and water use efficiency (WUE) under each N application rate were maximum, and the Op-wtd decreased with the increase in N application. The Op-wtd corresponding to the higher velocity of groundwater consumption (Gv) appeared at the late jointing stage, which was significantly higher than other WTD treatments under the same N fertilization. WTD significantly affected the Gv during the seeding to the regreening stage and maturity stage; the interaction of N application, WTD, and N application was significant from the jointing to the filling stage. The GC, leaf area index (LAI), and yield increased with an increase of N application at 0.6-0.9-m depth-for example, the yield and the WUE of the NF300 treatment with 0.6-m depth were significantly higher than those of the NF150-NF240 treatment at 20.51%, and 14.81%, respectively. At 1.2-1.5-m depth, the N application amount exceeding 150-240 kg/ha was not conducive to wheat growth, groundwater use, grain yield, and WUE. The yield and the WUE of 150-kg/ha treatment were 15.02% and 10.67% higher than those of 240-300-kg/ha treatment at 1.2-m depth significantly. The optimum N application rate corresponding to yield indicated a tendency to decrease with the WTD increase. Considering the winter wheat growth attributes, GC, yield, and WUE, application of 150-240 kg/ha N was recommended in our experiment.

Keywords: grain yield; leaf area index; principal component analysis; velocity of groundwater consumption; water use efficiency.

Grants and funding

We are grateful to the National Key R&D Program of China (no. 2021YFD1700900), Central Public-Interest Scientific Institution Basal Research Fund (no. FIRI20210105 and no. CAAS-ZDRW202201), and the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (no. CAAS-ASTIP).