Pedosphere (5): 914--930, 2025
ISSN 1002-0160/CN 32-1315/P
©2025 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Integrated ammonium and nitrate nitrogen supply alters the composition and functionalities of rice rhizosphere bacterial communities and enhances nitrogen use efficiency |
Zaid KHAN1, Xujian YANG1, Xianting FAN1, Songpo DUAN1, Chunmei YANG1, Mohammad Nauman KHAN3, Anas IQBAL4, Hong SHEN1 , Youqiang FU2 |
1 College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China)
2 Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640 (China)
3 Research Center for Physiology and Ecology and Green Cultivation of Tropical Crops, College of Tropical Crops, Hainan University, Haikou 570228 (China)
4 College of Agriculture, South China Agricultural University, Guangzhou 510642 (China) |
| ABSTRACT |
| Nitrogen (N) is the most important nutrient for plants; however, microbe-mediated N transformation under different N forms is unclear. This experiment investigated the effects of four treatments fertilized with various N forms, no N (control, CK), 100% ammonium N (AN), 100% nitrate N (NN), and 50% ammonium N + 50% nitrate N (ANNN), on soil chemical properties, rhizosphere bacterial network, and rice growth. The ANNN treatment enhanced soil pH by 6.9%, soil organic carbon by 12%, and microbial biomass N (MBN) by 60% compared to CK. The linear discriminant effect size (LEfSe) analysis indicated four highly abundant biomarkers of bacterial communities each in the CK, NN, and AN treatments, while the ANNN treatment showed six highly abundant biomarkers with maximum effect size and linear discriminant analysis (LDA) score > 4. The 16S rRNA gene-predicted functions under PICRUST indicated glutathione metabolism and proteasome and Tax4Fun recorded amino acid metabolism in the ANNN treatment. The combination of ammonium and nitrate N (i.e., the ANNN treatment) significantly increased the expression levels of the genes encoding N metabolism, including AMT1, NRT2.1, GS1, and GOGAT1, and induced 39%, 27%, 35%, and 38% increase in nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate synthase, respectively, in comparison to CK. In addition, the ANNN treatment promoted rice leaf photosynthetic rate by 37%, transpiration rate by 41%, CO2 exchange rate by 11%, and stomatal conductance by 18% compared to CK, while increased N use efficiency (NUE) by 10% and 19%, respectively, compared to the AN and NN treatments. These findings suggest that the combination of ammonium and nitrate N can promote bacterial community abundance, composition, and functional pathways by improving soil properties and can increase NUE and rice growth. This study provides a theoretical basis for the rational application of N fertilizers and the implications of this approach for future sustainable crop production. |
| Key Words: co-occurrence network,linear discriminant analysis,microbial biomass nitrogen,nitrogen metabolism,rice production |
| Citation: Khan Z, Yang X J, Fan X T, Duan S P, Yang C M, Khan M N, Iqbal A, Shen H, Fu Y Q. 2025. Integrated ammonium and nitrate nitrogen supply alters the composition and functionalities of rice rhizosphere bacterial communities and enhances nitrogen use efficiency. Pedosphere. 35(5):914-930. |
| |
|
View Full Text
|
|
|
|
