Effects of Camellia oleifera clone selection on soil nutrient and microbial community structure

The purpose of this study was to clarify the effects of biochar on the diversity of bacteria and fungi in the rice root zone and to reveal the changes in soil microbial community structure in the root zone after biochar application to provide a scientific basis for the improvement of albic soil. Rice and corn stalk biochar were mixed with albic soil in a pot experiment. Soil samples were collected at the rice maturity stage, soil nutrients were determined, and genomic DNA was extracted. The library was established using polymerase chain reaction (PCR) amplification. The abundance, diversity index, and community structure of the soil bacterial 16SrRNA gene V3 + V4 region and the fungal internal transcribed spacer-1 (ITS1) region were analyzed using Illumina second-generation high-throughput sequencing technology on the MiSeq platform with related bioinformatics. The results revealed that the biochar increased the soil nutrient content of albic soil. The bacteria ACE indexes of treatments of rice straw biochar (SD) and corn straw biochar (SY) were increased by 3.10% and 2.06%, respectively, and the fungi ACE and Chao indices of SD were increased by 7.86% and 14.16%, respectively, compared to conventional control treatment with no biochar (SBCK). The numbers of bacterial and fungal operational taxonomic units (OUT) in SD and SY were increased, respectively, compared to that of SBCK. The relationship between soil bacteria and fungi in the biochar-treated groups was stronger than that in the SBCK. The bacterial and fungal populations were correlated with soil nutrients, which suggested that the impacts of biochar on the soil bacteria and fungi community were indirectly driven by alternation of soil nutrient characteristics. The addition of two types of biochar altered the soil microbial community structure and the effect of rice straw biochar treatment on SD was more pronounced. This study aimed to provide a reference and basic understanding for albic soil improvement by biochar, with good application prospects.

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Soil nutrient stoichiometry affects the initial response of microbial community to trophic perturbation

10.1101/323709 ◽

2018 ◽

Author(s):

Kazumori Mise ◽

Runa Maruyama ◽

Yuichi Miyabara ◽

Takashi Kunito ◽

Keishi Senoo ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Phosphatase Activity ◽

Microbial Community Structure ◽

Community Dynamics ◽

Soil Nutrient ◽

Nutrient Stoichiometry ◽

Carbon And Nitrogen ◽

C:P Ratio ◽

The Impact

AbstractSoil microbes are drivers of global ecosystem functionality and are continuously subjected to external perturbations. It is fundamental for ecologists and environmental scientists to understand and further predict the microbes’ responses to these perturbations. A major and ubiquitous perturbation is the addition of chemical nutrients, including fertilizers and animal urine, to soil. Recent biogeographical studies suggest that soil nutrient stoichiometry (i.e., nutritional balance) determines microbial community structure and its functions with regard to material circulation. Given this information, here, we show that soil nutrient stoichiometry, or the bioavailable C:P ratio, determines the impact of nutrient addition on the soil’s microbial communities. We sampled two soils with similar carbon and nitrogen concentrations but with a 20-fold difference in phosphorus bioavailability. Soil microcosms with carbon and nitrogen amendments were constructed for both the soils. The phosphorus-depleted soil received prolonged effect from carbon and nitrogen amendments: the phosphatase activity gradually increased over a 24-day incubation period and the microbial community structure did not present recovery to its initial state. In contrast, in the other soil, both phosphatase activity and microbial community structure gradually returned to those of the control samples. Phosphorus depletion mitigated carbon and nitrogen intake; therefore, the effects of carbon and nitrogen amendment lasted longer. Our results demonstrate that nutritional stoichiometry is a strong predictor of microbial community dynamics in response to trophic perturbation, particularly when considering the length of time the trait of perturbation persists in the soil.

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