Maize-Soybean Intercropping at Optimal N Fertilization Increases the N Uptake, N Yield and N Use Efficiency of Maize Crop by Regulating the N Assimilatory Enzymes
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Date
2023
Authors
Nasar, Jamal
Zhao, Chang Jiang
Khan, Rayyan
Gul, Hina
Gitari, Harun
Shao, Zeqiang
Abbas, Ghulam
Haider, Imran
Iqbal, Zafar
Ahmed, Waqas
Journal Title
Journal ISSN
Volume Title
Publisher
ResearchGate
Abstract
Introduction: Surplus use of chemical nitrogen (N) fertilizers to increase
agricultural Q9 production causes severe problems to the agricultural
ecosystem and environment. This is contrary to N use efficiency and
sustainable agricultural production.
Methods: Hence, this study was designed to investigate the effect of
maizesoybean intercropping on N uptake, N yield, N utilization use
efficiency, and the associated nitrogen assimilatory enzymes of maize crops
under different N fertilization for two consecutive years 2021-2022.
Results: The findings of the study showed that intercropping at the optimal N
rate (N1) (250 kg N ha-1) increased significantly maize grain yield by 30 and
34%, residue yield by 30 and 37%, and 100-grain weight by 33 and 39% in the
year 2021 and 2022, respectively. As compared with mono-cropping, at this
optimal N rate, the respective increase (of maize’s crop N yield indices) for 2021
and 2022 were 53 and 64% for grain N yield, and 53 and 68% for residue N yield.
Moreover, intercropping at N1 resulted in higher grain N content by 28 and 31%,
residue N content by 18 and 22%, and total N uptake by 65 and 75% in 2021 and
2022, respectively. The values for the land equivalent ratio for nitrogen yield
(LERN) were greater than 1 in intercropping, indicating better utilization of N
under the intercropping over mono-cropping. Similarly, intercropping
increased the N assimilatory enzymes of maize crops such as nitrate
reductase (NR) activity by 19 and 25%, nitrite reductase (NiR) activity by 20 and
23%, and glutamate synthase activity (GOGAT) by 23 and 27% in 2021 and 2022,
respectively. Consequently, such increases resulted in improved nitrogen use
efficiency indices such as N use efficiency (NUE), partial factor nitrogen use
efficiency (PFNUE), nitrogen uptake efficiency (NUpE), and nitrogen agronomic
efficiency (NAE) under intercropping than mono-cropping.
Conclusion: Thus, this suggests that maize-soybean intercropping under
optimal N fertilization can improve the nitrogen status and nitrogen use
efficiency of maize crops by regulating the nitrogen assimilatory enzymes,
thereby enhancing its growth and yield. Therefore, prioritizing intercropping
over an intensive mono-cropping system could be a better option for
sustainable agricultural production.
Description
Article
Keywords
maize-soybean intercropping, nitrogen yield, nitrogen use efficiency, nitrogen assimilatory enzymes, agricultural sustainability
Citation
Nasar, J., Zhao, C. J., Khan, R., Gul, H., Gitari, H., Shao, Z., ... & Yang, J. (2022). Maize-soybean intercropping at optimal N fertilization increases the N uptake, N yield and N use efficiency of maize crop by regulating the N assimilatory enzymes. Frontiers in Plant Science, 13.