Combination of biochar and AMF promotes phosphorus utilization by stimulating rhizosphere microbial co-occurrence networks and lipid metabolites of Phragmites

Agricultural biochar and arbuscular mycorrhizal fungi were used to promote the growth of Phragmites in the structural damaged and nutritional imbalanced littoral zone soils. Wheat straw biochar played a significant role in improving soil porosity and supplementing available phosphorus to 79.20 +/- 3.20 mg/kg, compared with CK at 17.50 +/- 0.88 mg/kg. The addition of Diversispora versiformis improved the plant net photosynthetic rate reaching up to 25.66 +/- 0.65 mu mol center dot m-2 center dot s-1, which was 36.60 % higher than CK. The combination of biochar and fungi contributed to the whole plant dry weight biomass of 32.30 % and 234.00 % higher than the single biochar or AMF amendment groups, respectively. Meanwhile, the analysis of microbial co-occurrence networks showed the most relevant networks node species were mainly Talaromyces, Chaetomiacea and Gemmatimonadetes etc. Root lipid metabolite of Glycerophospholines further proved that phosphorus utilization was also enhanced endogenously in the rhizosphere soil. These results indicate that the combination of biochar and arbuscular mycorrhizal fungi play synergic role in enhancing phosphorus utilization endogenously and exogenously.

Automated summary

This study demonstrates that the combination of agricultural biochar and arbuscular mycorrhizal fungi can promote the growth of Phragmites in structurally damaged and nutritionally imbalanced littoral zone soils. Biochar improves soil porosity and phosphorus availability, while the addition of fungi enhances the plant's photosynthetic rate and biomass. In addition, microbial co-occurrence network analysis reveals the significance of this combination in phosphorus utilization in the rhizosphere soil.