Soil microbiome biomass,activity, composition and CO2 emissions in a long-term organic and conventional farming systems

The implementation of environmentally friendly agricultural policies has increased the need to compare agricultural aspects of conventional (CON) and organic farming (ORG) systems. The objective of the present work was to compare the effects of an organic and conventional long-term experiment on bacterial and fungal biomass and activity, as well as soil CO₂ emission and readily available nitrogen forms in a soil cultivated with Helianthus annuus L. The microbial biomass was more active and abundant in ORG as well as soil CO₂ emission. Despite being less abundant, fungi were more active than bacteria in both ORG and CON experiments. 16S rRNA gene sequencing showed that the ORG treatment had a significantly greater bacterial richness than CON. Cyanobacteria, Actinobacteria and Proteobacteria were the most abundant phyla contributing more than others to the differences between the two systems. Moreover, the soil ${\mathit{NH}}_4^{+}$ and ${\mathit{NO}}_2^{-}$ content was not significantly different between ORG and CON, while ${\mathit{NO}}_3^{-}$ was less in ORG. ORG sunflower yield was significantly less compared with CON. While much remains to be discovered about the effects of these agricultural practices on soil chemical properties and microbial diversity, our findings may contribute to this type of investigation.     

Development of a SYBR Green-based real-time quantitative polymerase chain reaction assay to detect enzootic nasal tumor virus in goats

Enzootic nasal adenocarcinoma is a contagious respiratory disease in goats that is caused by the enzootic nasal tumor virus 2 (ENTV-2). In order to increase the number of available detection methods for ENTV-2, we developed a SYBR Green real-time polymerase chain reaction (SGrPCR) assay that targets the gag gene of ENTV-2. The low limit of detection of the assay was 3.68 × 10¹ copies/μL, a hundredfold more sensitive than conventional PCR. The melt curve showed a single sharp melt peak at 83°C, which indicated that there was no non-specific amplification or primer dimer formation. The intra-assay and inter-assay coefficients of variation were 1.58% and 1.82%, respectively. There was no cross-reactivity with closely related goat viruses (i.e., orf virus, peste des petits ruminants virus, goatpox virus, foot-and-mouth disease virus) and endogenous retroviruses. In conclusion, the SGrPCR assay is specific for the gag gene of ENTV-2 and provides a rapid and sensitive approach for detecting ENTV-2 in clinical samples.