Soil pH and electrical conductivity are key edaphic factors shaping bacterial communities of greenhouse soils in Korea

Abstract

Soil microorganisms play an essential role in soil ecosystem processes such as organic matter decomposition, nutrient cycling, and plant nutrient availability. The land use for greenhouse cultivation has been increasing continuously, which involves an intensive input of agricultural materials to enhance productivity; however, relatively little is known about bacterial communities in greenhouse soils. To assess the effects of environmental factors on the soil bacterial diversity and community composition, a total of 187 greenhouse soil samples collected across Korea were subjected to bacterial 16S rRNA gene pyrosequencing analysis. A total of 11,865 operational taxonomic units at a 97% similarity cutoff level were detected from 847,560 sequences. Among nine soil factors evaluated; pH, electrical conductivity (EC), exchangeable cations (Ca, Mg, Na, and K), available PO, organic matter, and NO-N, soil pH was most strongly correlated with bacterial richness (polynomial regression, pH: R = 0.1683, P < 0.001) and diversity (pH: R = 0.1765, P < 0.001). Community dissimilarities (Bray-Curtis distance) were positively correlated with Euclidean distance for pH and EC (Mantel test, pH: r = 0.2672, P < 0.001; EC: r = 0.1473, P < 0.001). Among dominant phyla (> 1%), the relative abundances of Proteobacteria, Gemmatimonadetes, Acidobacteria, Bacteroidetes, Chloroflexi, and Planctomycetes were also more strongly correlated with pH and EC values, compared with other soil cation contents, such as Ca, Mg, Na, and K. Our results suggest that, despite the heterogeneity of various environmental variables, the bacterial communities of the intensively cultivated greenhouse soils were particularly influenced by soil pH and EC. These findings therefore shed light on the soil microbial ecology of greenhouse cultivation, which should be helpful for devising effective management strategies to enhance soil microbial diversity and improving crop productivity.

Comparisons of Soil Properties, Enzyme Activities and Microbial Communities in Heavy Metal Contaminated Bulk and Rhizosphere Soils of Robinia pseudoacacia L. in the Northern Foot of Qinling Mountain

“…Soil EC has been used as a good indicator of soil stress level and is generally correlated with soil pH. In agreement with our findings, Kim et al [67] suggested that the bacterial community in intensively cultivated greenhouse soils could be particularly affected by soil pH and EC. Soil pH had also shown one of the most important environmental factors impacting bacterial abundance and diversity in natural and agricultural ecosystems [68].…”

Diversity of rhizosphere and endophytic fungi in Atractylodes macrocephala during continuous cropping

“…The change in fungal composition may be a result of both fertilization and the observed increase in hydrolysis N cycling (Thompson & Kao-Kniffin, 2019). Agricultural management practices, such as high fertilizer usage and restricted irrigation can immensely influence electrical conductivity variation (Adviento-Borbe et al, 2006;Kim et al, 2016). Electrical conductivity is associated with soil salinity and our results suggest it may be an important predictor of fungal community compositions in continuous cropping soils of A. macrocephala.…”

Total RNA-sequencing reveals multi-level microbial community changes and functional responses to wood ash application in agricultural and forest soil

“…Bacteroidetes, Alphaproteobacteria and Betaproteobacteria were stimulated by wood ash application. Members of Bacteroidetes benefit from wood ash application (Noyce et al , 2016; Bang-Andreasen et al , 2017); they are initial metabolizers of labile carbon and respond positively to increased soil pH and electrical conductivity (Fierer et al , 2007; Lauber et al , 2009; Kim et al , 2016). Alpha- and Betaproteobacteria are also generally copiotrophic (Fierer et al , 2007; Cleveland et al , 2007); Betaproteobacteria thrive in soils with higher pH (Kim et al , 2016), whereas Alphaproteobacteria are favoured at high N availability (Nemergut et al , 2010; Fierer et al , 2012).…”