Bacterial communities in proso millet root‐associated compartments are regulated by growth period and mulching regime

Abstract

Mulching regimes have a promoted impact on the soil hydrothermal environments and crop productions. However, the time‐dependent variations in root‐associated microbial communities under distinct mulching regimes in the Loess Plateau have not been thoroughly explored. Here, we investigated the regulatory impacts of plastic film mulching (FM) and ridge‐furrow mulching system (RF) on the microbial community compositions, diversities, and ecological networks in the distinct compartments (e.g., root, rhizosphere, and bulk soil) at jointing and flowering periods of proso millet, and we compared these two regimes to no mulching (NM). Mulching regimes improved the bulk and rhizosphere soil quality at jointing period, whereas reduced them at flowering period. Bacterial structure and composition of the three compartments were significantly influenced by growth periods and mulching regimes. Furthermore, mulching regimes effectively increased the alpha diversities of rhizosphere and root communities at flowering period. Soil temperature and total N were the most essential variables affecting the bulk soil and rhizosphere community structure, respectively. With the growth and development of proso millet, the network complexity and stability increased, and the abundance of different modules in the three compartments were regulated by mulching regimes. Proteobacteria and Acidobacteriota were the keystone species at jointing period, whereas, at flowering period, only Proteobacteria were the keystone species. In addition, FM regime significantly increased the species interaction and abundance of keystone taxa than those of non‐mulching at both periods. These results highlighted that mulching regimes were observed to be a recommended selection for improving soil quality, regulating bacterial diversity and structure, and stabilizing the species interaction, thereby providing guidance for choosing the ideal cultivation techniques from the perspective of microbial ecology in the Loess Plateau.

Microbial functional genes within soil aggregates drive organic carbon mineralization under contrasting tillage practices

“…Principal coordinate analysis (PCoA) was used to determine the clustering of distinct treatments using the pcoa function in “ape” package. Permutational multivariate analysis of variance (PERMANOVA) was conducted to establish the influence of tillage practice, aggregate fraction, and their interactions on bacterial community differences based on Bray–Curtis distance using the “vegan” package in R (Tian et al, 2022). DEGSeq analysis was used to identify significantly different C functional genes between soils subjected to different tillage treatments using the “DESeq2” package in R (Schmidt et al, 2019).…”