Land use indirectly affects the cycling of multiple nutrients by altering the diazotrophic community in black soil

Abstract

BACKGROUND: Diazotrophic bacteria, as one of most important group of soil microorganisms, play critical roles in multiple ecosystem functions (i.e., multifunctionality). However, little information is available about the diazotrophic community in driving soil nutrient cycling and multifunctionality at different depths with distinct vegetation in the black soil region of northeastern China. To learn the interactions among land use, cycling of multiple nutrients and the diazotrophic community, we performed this study in grassland (GL), forested land and a cropland (CL) in soils at depths of 0-15 cm and 15-35 cm.RESULTS: The highest nifH gene abundances were found in the CL treatment, while the highest diazotrophic species richness and diversity were detected in the GL in both soil layers. The nifH gene abundance was directly/positively correlated with soil bulk density and negatively correlated with land use and soil depth. The index of multiple nutrient cycling was directly/ negatively affected by soil depth and indirectly/positively affected by land use. Land use directly/negatively affected soil pH and thus indirectly affected the diazotrophic community composition and the nutrient cycling index. The diversity and community composition of the diazotrophs together accounted for 95% of the differences in the multiple nutrient cycling index.CONCLUSION: Soil diazotrophic communities undertake important roles in maintaining nutrient cycling and soil multifunctionality at depths of 0-15 cm and 15-35 cm layers with different land uses of the black soil region of China.

Symbiotic diazotrophs in response to yak grazing and Tibetan sheep grazing in Qinghai-Tibetan plateau grassland soils

“…Thus, this study evaluated the influence of grazing patterns on diazotrophic communities in Qinghai-Tibetan Plateau grassland under moderate intensity grazing. The decreased of nifH gene copies under all grazing treatments were consistent with previous reports (Yan et al, 2021). In the present study, compared with CK, both singly and mixed grazing treatment reduced the nifH gene copies.…”

“…Meanwhile, the dominant bacteria had significant correlation with legume biomass suggested the abundance of nitrogen-fixing bacteria in soil is influenced by the foraging strategies of different livestock. Among the Proteobacteria and Firmicutes phylum, taxa such as Rhizobiales and Bacillales species are well known for forming root nodules with legumes and conducting symbiotic nitrogen fixation, and varying significantly in abundance among the types of land use ( Yan et al, 2021 ).…”

Nitrogen acquisition and retention pathways in sustainable perennial bioenergy grass cropping systems

“…Background diazotrophs in soil also have substantial impacts on the formation of grass–diazotroph associations under the influence of the host's selection mechanisms. Soil diazotroph community composition can be directly influenced by soil physiochemical properties such as soil pH and texture, and also indirectly influenced by land‐use history, previous cropping and management practices (Fan et al., 2018; Han et al., 2019; Wang et al., 2021; Yan, Han, et al., 2022; Yu et al., 2020). The ecology of associative BNF is further complicated by the interactive effects of biological factors and environmental conditions (climatic and edaphic factors) and results in various levels of associative BNF, leaving several aspects of uncharacterized, such as the localization and the precise N contribution of BNF.…”

The effect of alfalfa cultivation on improving physicochemical properties soil microorganisms community structure of grey desert soil

“…Their abundance reflects and determines the ecological characteristics of the soil 14 . These microorganisms are involved in organic matter, degradation, humus formation 15 , and the transformation and cycling of soil nutrients, making them essential for improving soil structure 16 . Therefore, understanding the diversity and community composition of soil microorganisms is relevant.…”