Effect of long-term fertilization strategies on bacterial community composition in a 35-year field experiment of Chinese Mollisols

Abstract

Bacteria play vital roles in soil biological fertility; however, it remains poorly understood about their response to long-term fertilization in Chinese Mollisols, especially when organic manure is substituted for inorganic nitrogen (N) fertilizer. To broaden our knowledge, high-throughput pyrosequencing and quantitative PCR were used to explore the impacts of inorganic fertilizer and manure on bacterial community composition in a 35-year field experiment of Chinese Mollisols. Soils were collected from four treatments: no fertilizer (CK), inorganic phosphorus (P) and potassium (K) fertilizer (PK), inorganic P, K, and N fertilizer (NPK), and inorganic P and K fertilizer plus manure (MPK). All fertilization differently changed soil properties. Compared with CK, the PK and NPK treatments acidified soil by significantly decreasing soil pH from 6.48 to 5.53 and 6.16, respectively, while MPK application showed no significant differences of soil pH, indicating alleviation of soil acidification. Moreover, all fertilization significantly increased soil organic matter (OM) and soybean yields, with the highest observed under MPK regime. In addition, the community composition at each taxonomic level varied considerably among the fertilization strategies. Bacterial taxa, associated with plant growth promotion, OM accumulation, disease suppression, and increased soil enzyme activity, were overrepresented in the MPK regime, while they were present at low abundant levels under NPK treatment, i.e. phyla Proteobacteria and Bacteroidetes, class Alphaproteobacteria, and genera Variovorax, Chthoniobacter, Massilia, Lysobacter, Catelliglobosispora and Steroidobacter. The application of MPK shifted soil bacterial community composition towards a better status, and such shifts were primarily derived from changes in soil pH and OM.

The Status of Soil Microbiome as Affected by the Application of Phosphorus Biofertilizer: Fertilizer Enriched with Beneficial Bacterial Strains

“…Several studies have proven that fertilization strategies have an impact on the genetic diversity of soil microbial communities [83][84][85]. Our study revealed that the application of mineral fertilizer enriched with beneficial bacterial strains increased the number of 16S rDNA OTU's in BA soil and ITS1 OTU's for both soil types.…”

Microbial Diversity and Antimicrobial Resistance Profile in Microbiota From Soils of Conventional and Organic Farming Systems

“…Only rarely detected lower taxons were different between the soils. From the genera that were present in significantly different quantities (higher in conventional farming), Sphingomonas and Gemmatimonas were observed previously to be increased in farming with mineral fertilizers (Ma et al, 2018). We also found Rhodanobacter genus, which was previously connected with denitrification of soil (Green et al, 2012), present only in conventional farming soil (0.37% relative abundance) and absent from organic farming soil.…”

Straw input can parallelly influence the bacterial and chemical characteristics of maize rhizosphere

“…In this work, at the phylum level, Proteobacteria firstly dominated in all the soil samples, probably due to a wide range of complex organic molecules can be utilized by the members of this phylum [46]. Because the members of phylum Proteobacteria have been reported to facilitate the horizontal transfer of genes related to photosynthesis, its high abundance is particularly vital for crop growth [47]. Furthermore, many taxa within this phylum exhibit disease-suppression activity, such as defending plant roots from fungal pathogen infection, which may improve the health of plant and soil [27].…”

“…The result of Banerjee et al (2016) indicated that the Acidobacteria and Gemmatimonas were the keystone taxa during organic matter decomposition in an arable soil, and these taxa were importance in carbon turnover [20]. Ma et al (2018) reported that the Acidobacteria increased with the decline of soil pH, when in the fertilizer rich regime [47]. In the current study, Acidobacteria formed the second largest group but was lower in SC, SD and BC samples compared to CK (Figure 2(a)), suggesting the improvement of soil nutrition and deacidification effect by straw incorporation or BC addition.…”

“…The carbohydrate metabolism pathways including glycolysis, citrate cycle, galactose metabolism, pyruvate metabolism, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism showed significant association with organic acids ( Figure S4). The chemical composition of rhizosphere and root exudation is important for the attraction and shaping of microbial communities in rhizosphere [6,47,54]. The rhizodeposition of organic molecules can increase nutrient availability and provide sufficient nutrients to improving microbial growth in the rhizosphere [18,41].…”