Soil pH: a key edaphic factor regulating distribution and functions of bacterial community along vertical soil profiles in red soil of pomelo orchard

Abstract

Background Soil microbes exist throughout the soil profile and those inhabiting topsoil (0–20 cm) are believed to play a key role in nutrients cycling. However, the majority of the soil microbiology studies have exclusively focused on the distribution of soil microbial communities in the topsoil, and it remains poorly understood through the subsurface soil profile (i.e., 20–40 and 40–60 cm). Here, we examined how the bacterial community composition and functional diversity changes under intensive fertilization across vertical soil profiles [(0–20 cm (RS1), 20–40 cm (RS2), and 40–60 cm (RS3)] in the red soil of pomelo orchard, Pinghe County, Fujian, China. Results Bacterial community composition was determined by 16S rRNA gene sequencing and interlinked with edaphic factors, including soil pH, available phosphorous (AP), available nitrogen (AN), and available potassium (AK) to investigate the key edaphic factors that shape the soil bacterial community along with different soil profiles. The most dominant bacterial taxa were Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, Crenarchaeota, and Bacteriodetes. Bacterial richness and diversity was highest in RS1 and declined with increasing soil depth. The distinct distribution patterns of the bacterial community were found across the different soil profiles. Besides, soil pH exhibited a strong influence (pH ˃AP ˃AN) on the bacterial communities under all soil depths. The relative abundance of Proteobacteria, Actinobacteria, Crenarchaeota, and Firmicutes was negatively correlated with soil pH, while Acidobacteria, Chloroflexi, Bacteriodetes, Planctomycetes, and Gemmatimonadetes were positively correlated with soil pH. Co-occurrence network analysis revealed that network topological features were weakened with increasing soil depth, indicating a more stable bacterial community in the RS1. Bacterial functions were estimated using FAPROTAX and the relative abundance of functional bacterial community related to metabolic processes, including C-cycle, N-cycle, and energy production was significantly higher in RS1 compared to RS2 and RS3, and soil pH had a significant effect on these functional microbes. Conclusions This study provided the valuable findings regarding the structure and functions of bacterial communities in red soil of pomelo orchards, and highlighted the importance of soil depth and pH in shaping the soil bacterial population, their spatial distribution and ecological functioning. These results suggest the alleviation of soil acidification by adopting integrated management practices to preserve the soil microbial communities for better ecological functioning.

The Application of Mixed Organic and Inorganic Fertilizers Drives Soil Nutrient and Bacterial Community Changes in Teak Plantations

“…The bacterial co-occurrence network was performed to reveal the interrelationships between species and the complexity of community structure and function [ 29 , 30 , 31 ]. Previous studies confirmed that alterations of community structure and bacterial network were closely related to soil properties, such as pH [ 32 ], soil matter organic [ 33 , 34 ] and available phosphorus [ 35 ], which have been considered major drivers of variation in biotopes. Although symbiotic network patterns were universally applied in forest ecosystems, the response of complex bacterial communities to the application of mixed organic and inorganic fertilizers in teak plantations is still unknown.…”

Diversity in rhizospheric microbial communities in tea varieties at different locations and tapping potential beneficial microorganisms

“…This study showed that among the four tea gardens, the pH of the Hangzhou tea garden was lower than that of the Shengzhou tea garden, which may be due to the greater age of the tea garden, resulting in the decrease in the pH of the tea garden soil ( Table 1 ). Previous literature revealed that the bacterial community was significantly negatively correlated with soil pH ( Zhou et al, 2017 ), and it is further confirmed that pH is a key factor affecting the microbial community in tea gardens ( Muneer et al, 2022 ). As shown in Table 1 , although the pH values of the four tea gardens are similar, the significance analysis by SPSS shows that the pH values of tea gardens are significantly different among tea gardens ( p < 0.01), and the microbial abundance of the two locations is also significantly different ( Figure 3 ) ( p < 0.05).…”

Contrasting effects of organic materials versus their derived biochars on maize growth, soil properties and bacterial community in two type soils

“…For two biochars, there was no significant difference between straw-derived biochar and control, while manure-derived biochar could altered bacterial community composition in the red soil, by increasing the relative abundance of Proteobacteria and Bacteroidota, and decreasing that of Firmicutes, the increased soil pH, basal respiration, enzyme activities and decreased soil available N are likely to be one of the main reasons, the results of correlation analysis can support these suggestions ( Figure 5B ). Some studies have displayed that Proteobacteria are significantly regulated by the soil nutrient indicators, and Firmicutes are generally positively correlated with the soil AN and negatively correlated with the soil pH ( Lu et al, 2020 ; Muneer et al, 2022 ).…”