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Straw is widely incorporated into soil worldwide, but most studies have concentrated on the effects of straw mulching or incorporation with topsoil. To determine the effect of depth of straw incorporation on bacterial and fungal communities, we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments: conventional tillage (CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage (SCT, tillage to a depth of 15 cm), inversion tillage (IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage (SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm after harvest. The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT. Fungal abundance was higher with straw incorporation, but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT. Path length in the bacterial network was shorter and connectivity was higher in CT + SCT than in IT + SIT, leading to a more complex ecosystem, and the fungal network had opposite patterns. The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment, which may increase bacterial network resistance to environmental disturbances and unstable fungal networks, resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources. [ABSTRACT FROM AUTHOR]

Bacteria are the most abundant soil microbes and are sensitive to environmental change, especially soil carbon (C) and nitrogen (N) dynamics. The bacterial diversity of rhizosphere and bulk soils associated with desert plants is not well understood. In this study, we measured the properties of rhizosphere and bulk soils at different depths (0–20, 20–40, 40–60, and 60–80 cm), the diversity of bacterial communities (16S rDNA amplicon sequencing), and their relationships with Anabasis aphylla in the southern margin of the Gurbantunggut Desert, Junggar Basin, China. A total of 11,420 operational taxonomic units (OTUs) were obtained from 40 soil samples, belonging to 641 genera, 269 families, 137 orders, 61 classes, and 44 phyla. There were significant differences in electrical conductivity (EC), available nitrogen (AN), available phosphorus (AP), available potassium (AK), and bacterial diversity. The dominant bacterial communities of the rhizosphere and bulk soils at the phylum level were Actinobacteria, Proteobacteria, and Bacteroidetes. At the genus level, the dominant communities of the rhizosphere and bulk soils were Halomonas and Glycomyces, respectively. At different soil depths, the abundances of bacteria in the soil were 10.2% (0–20 cm) > 8.4% (20–40 cm) > 8.3% (60–80 cm) > 6.2% (40–60 cm). Our results indicate that bacteria in the phyla Actinobacteria and Proteobacteria, as well as the genus Halomonas, are key to the drought and salt tolerance of A. aphylla. [ABSTRACT FROM AUTHOR]