ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Plant Symbiotic Interactions
Microbial-Inoculated Biochar Combined with Nitrogen Mitigates Salinity Stress in Rice by Reducing Salt Accumulation and Enhancing Soil–Plant Interactions
Hafiz Muhammad Mazhar Abbas 1
Mohammad Nauman Khan 1
Haider Sultan 1
Asad Shah 1
Fahd Rasul 2
Ashar Tahir 1
Muhammad Nafees-Ur- Rehman 1
Lixiao Nie 1
1. Hainan University, Haikou, China
2. University of Agriculture Faisalabad Faculty of Agriculture, Faisalabad, Pakistan
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Abstract
Soil salinity has become one of the major environmental factors limiting plant growth and development. Microbial inoculated biochar and N can enhance plant productivity under saline conditions through improving chemical and biological properties of soil and plants self-defense system. A pot experiment with eleven treatments was conducted to evaluate the effectiveness of rice husk biochar, with and without microbial (bacterial and fungal) inoculation, combined with nitrogen (N) in mitigating salinity stress (6.8 ds/m EC) in rice. Treatments included sole nitrogen (60 and 120 kg ha⁻¹), sole biochar (1%), microbial-inoculated biochar (fungal or bacterial), and their combinations with nitrogen at 60 and 120 kg ha⁻¹, applied under both saline and non-saline conditions. Two rice varieties were used: the salt-tolerant Shuang Liang You 138 (SLY138) and the salt-sensitive Jing Liang You 534 (JLY534). The experiment was conducted for 80 days. The combined application of bacterial-inoculated biochar (BB) and nitrogen fertilizer was more effective than rice husk biochar alone in improving soil microbial and chemical properties. Notably, bacterial inoculated biochar combined with nitrogen 120 kg ha─1 (BB + N) treatments increased the abundance of pollution-degrading Desulfobacterota and salt-tolerant Actinobacterota. The enrichment of these microbial groups was associated with prolonged incubation time and reduced soil Na⁺ concentrations, which collectively contributed to improved rice growth. Compared to BC treatment, BB + N120 treatment produced higher Proline, total soluble sugar (TSS), leaf water potential (Ψw), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) in SLY138 by 120, 167, 30.23, 50, 68 and 57% respectively under saline conditions and NH4+-N, OM, bacterial and fungal community richness by 113.33, 40, 65.33 and 186.25% respectively. The salt tolerance of SLY138 may be correlated with enhanced activities of (SOD, POD and CAT), more accumulation of proline and total soluble sugar. The findings of our study demonstrate the effectiveness of modified biochar applications in mitigating salinity stress and enhancing rice growth in saline environments.
Summary
Keywords
Bacterial biochar, fungal biochar, Inoculation, microbial abundance, Saline water
Received
12 December 2025
Accepted
18 February 2026
Copyright
© 2026 Abbas, Khan, Sultan, Shah, Rasul, Tahir, Rehman and Nie. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Lixiao Nie
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