Improving maize carbon and nitrogen metabolic pathways and yield with nitrogen application rate and nitrogen forms

Fanhao Meng; Ruifu Zhang; Yuqin Zhang; Weimin Li; Yushan Zhang; Mingwei Zhang; Xuezhen Yang; Hengshan Yang

doi:10.7717/peerj.16548

Improving maize carbon and nitrogen metabolic pathways and yield with nitrogen application rate and nitrogen forms

PeerJ. 2024 Jan 2:12:e16548. doi: 10.7717/peerj.16548. eCollection 2024.

Authors

Fanhao Meng^{1

2}, Ruifu Zhang^{1

2}, Yuqin Zhang^{1

2}, Weimin Li^{1

2}, Yushan Zhang^{1

2}, Mingwei Zhang³, Xuezhen Yang^{1

2}, Hengshan Yang^{1

2}

Affiliations

¹ College of Agronomy, Inner Mongolia Minzu University, Tongliao, Inner Mongolia, China.
² Inner Mongolia Autonomous Region Feed Crop Engineering Technology Research Center, Inner Mongolia Minzu University, Tongliao, Inner Mongolia, China.
³ Xingan League Institute of Agriculture and Animal Husbandry Science, Wulanhaote, Inner Mongolia, China.

Abstract

Reduced fertilizer efficiency caused by excessive use of nitrogen (N) fertilizer is a major problem in agriculture and a hot topic of research. Most studies have focused on the effect of N application rate on N efficiency, whereas there are limited studies on changing the N form to improve N yield and efficiency. Here, the effects of different N application rates and nitrate-to-ammonium N ratios on post-anthesis carbon (C) and N metabolism and maize yield under shallow-buried drip irrigation were investigated. Two rates of N application (210 kg·ha^-1 (NA1) and 300 kg·ha^-1 (NA2)) and three nitrate-to-ammonium N ratios (2:1 (NF1), 3:1 (NF2), and 4:1 (NF3)) were utilized. Post-anthesis photosynthetic characteristics, activities of key enzymes in photosynthetic C and N metabolism, nonstructural carbohydrate content, post-anthesis N accumulation and transportation, yield, and N-use efficiency were determined. At both N application rates, NF2 treatment enhanced photosynthetic activity in the ear-leaf at silking stage and promoted key enzyme activities of C and N metabolic pathways, compared with NF1 and NF3. Furthermore, NF2 significantly increased nonstructural carbohydrate accumulation (4.00-64.71%), post-anthesis N accumulation and transportation (11.00-38.00%), and grain yield (2.60-13.08%). No significant differences between NA1 and NA2 were observed under NF2 in most of the measured variables; however, NA1 had higher N-use efficiency. Thus, the optimal treatment under shallow-buried drip irrigation was a N application rate of 210 kg ha^-1 and a nitrate-to-ammonium N ratio of 3:1. These findings provide theoretical guidance on appropriate N applications for high-yield maize production.

Keywords: Carbon and nitrogen metabolic pathways; Maize; Nitrate-to-ammonium nitrogen ratio; Yield.

MeSH terms

Ammonium Compounds*
Carbohydrates
Carbon
Fertilizers
Nitrates
Nitrogen
Photosynthesis
Zea mays*

Substances

Nitrates
Fertilizers
Carbon
Nitrogen
Ammonium Compounds
Carbohydrates

Grants and funding

This work was supported by the National Natural Science Foundation of China (No. 32160509) and the Natural Science Foundation of Inner Mongolia (No. 2021BS03005). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.