Bacterial community structure in maize stubble-amended soils with different moisture levels estimated by bar-coded pyrosequencing

Abstract

It is of ecological significance to investigate microbial communities in response to straw amendment and moisture in arable soils. However, in Chinese fluvo-aquic soils, these responses are still poorly understood. We designed an incubation experiment involving two soils with and without the addition of maize stubble at two moisture levels, and bacterial community structure at days 20, 80, and 200 after the start of incubation was assessed via bar-coded pyrosequencing of the 16S rDNA amplicons. In the presence of stubble with identical moisture level, we observed higher bacterial diversity and richness in long-term organic manure-fertilized soil compared with the unfertilized soil at days 20 and 80, which we attributed to the different quality and quantity of organic matter between the two soils. However, there was no significant difference in bacterial diversity and richness between the two soils at day 200, indicating that long-term straw amendment probably lessens the difference in bacterial community structure between the two soils. In the amended soils bacterial diversity, richness, and community composition at 25% of the water-holding capacity distinctly differed from those at 55% of the waterholding capacity, indicating that moisture strongly affects bacterial distribution in the amended soils. As stubble-C availability declined over time, the dominance of copiotrophic population weakened, and oligotrophic population was moderately abundant. Finally, our study suggests that dissolved organic carbon, which drives redistribution in copiotrophic and oligotrophic categories in response to the varying water and stubble-C availability, is a determinant of bacterial community composition in the amended soils.

Responses of soil microeukaryotic communities to short-term fumigation-incubation revealed by MiSeq amplicon sequencing

“…As nutrient conditions change (i.e., following fumigant removal there is a release of necromass), the redistribution of the microeukaryotic communities (i.e., copiotrophs and oligotrophs) probably occurs, leading to the changed community structure during the incubation period. Similarly, in a straw amendment incubation experiment, we also observed the redistributions of the arable soil bacterial and microeukaryotic communities as straw availability declined over time (Chen et al, 2014 , 2015 ).…”

Bacterial Community Structure after Long-term Organic and Inorganic Fertilization Reveals Important Associations between Soil Nutrients and Specific Taxa Involved in Nutrient Transformations

“…The OTUs primarily from Bacteroidetes, Betaproteobacteria, Gammaproteobacteria , and Acidobacteria were significantly enriched by long-term fertilization, especially combined organic-inorganic fertilization (Table 2 ). Bacteroidetes, Betaproteobacteria , and Gammaproteobacteria as copiotrophs thrive under conditions where substrate availability is high (Fierer et al, 2007 ; Eilers et al, 2010 ; Nemergut et al, 2010 ; Chen et al, 2015b ). Despite there are many oligotrophic members within the Acidobacteria phylum (Nemergut et al, 2010 ; Pascault et al, 2013 ), some Acidobacteria members were depleted but some were enriched by combined organic-inorganic fertilization (Table 2 ).…”

Long‐term straw returning affectsNitrospira‐like nitrite oxidizing bacterial community in a rapeseed‐rice rotation soil

“…Wheat straw addition to soil was reported to increase the yield of organic tomato. Crop‐straw (composted mixture of wheat straw, oil cake, and cotton cake) amendment increased microbial biomass, shifted microbial community structure, and decreased eukaryotic diversity and richness in soil . The successive process of microbial communities in control soils was found to be slower than that in straw‐amended soils in response to climate changes .…”