The use of green manures contributes to sustainable soil and nutrient management in agriculture;however, the responses of soil microbial communities to different fertilization regimes at the regional scale are uncerta...The use of green manures contributes to sustainable soil and nutrient management in agriculture;however, the responses of soil microbial communities to different fertilization regimes at the regional scale are uncertain. A study was undertaken across multiple sites and years in Hunan, Jiangxi, Anhui, Henan,Hubei, and Fujian provinces of South China to investigate the effects of green manuring on the structure and function of soil bacterial communities in rice-green manure cropping systems. The study included four treatments: winter fallow with no chemical fertilizer as a control(NF), milk vetch as green manure without chemical fertilizer(GM), winter fallow and chemical fertilizer(CF), and a combination of chemical fertilizer and milk vetch(GMCF).Significant differences were found in the responses of soil microbial communities at different sites, with sampling sites explaining 72.33%(F = 36.59,P = 0.001) of the community composition variation. The bacterial communities in the soils from Anhui, Henan, and Hubei were broadly similar, while those from Hunan were distinctly different from other locations. The analysis of Weighted UniFrac distances showed that milk vetch changed soil microbial communities compared with winter fallow. Proteobacteria and Chloroflexi predominated in these paddy soils;however, the application of green manures increased the relative abundance of Actinobacteria. There was evidence showing that the functional microbes which play important roles in the cycling of soil carbon, nitrogen(N), and sulfur(S) changed after several years of milk vetch utilization(linear discriminant analysis score > 2). The abundance of methane-oxidizing bacteria and S-reducing bacteria increased, and microbes involved in N fixation, nitrification, and denitrification also increased in some provinces. We concluded that the application of milk vetch changed the bacterial community structure and affected the functional groups related to nutrient transformation in soils at a regional scale.展开更多
Background:Few studies have incorporated the evolutionary insights provided by analysis of phylogenetic structure along with community composition to assess the effects of exotic invasion on freshwater wetlands.Here,w...Background:Few studies have incorporated the evolutionary insights provided by analysis of phylogenetic structure along with community composition to assess the effects of exotic invasion on freshwater wetlands.Here,we assess the taxonomic and phylogenetic relationships among acid seep springs to investigate the potential homogenization or resistance of communities due to invasion of an exotic grass.Results:Multivariate community analyses indicated differences in community and phylogenetic composition and dispersion among acid seep springs,associated with gradients in soil moisture,canopy cover,and phylogenetic diversity.By contrast,univariate analyses showed differences in taxonomic diversity but not phylogenetic diversity among acid seep springs.Conclusions:Despite exotic invasion,individual acid seep springs remained taxonomically and phylogenetically distinct from each other.Taxonomic and phylogenetic diversity metrics revealed different aspects of composition,reinforcing the importance of including both in analyses of plant communities for understanding community assembly following exotic invasion and for management purposes.Within acid seep springs,taxonomic and phylogenetic composition appear to be driven more through environmental filtering by light and moisture than by the competitive effects following invasion of an exotic grass in support of Elton’s biotic resistance hypothesis.展开更多
基金supported by the earmarked fund for Modern Agro-industry Technology Research System-Green Manure,China (No.CARS-22)the National Natural Science Foundation of China (No.42007071)。
文摘The use of green manures contributes to sustainable soil and nutrient management in agriculture;however, the responses of soil microbial communities to different fertilization regimes at the regional scale are uncertain. A study was undertaken across multiple sites and years in Hunan, Jiangxi, Anhui, Henan,Hubei, and Fujian provinces of South China to investigate the effects of green manuring on the structure and function of soil bacterial communities in rice-green manure cropping systems. The study included four treatments: winter fallow with no chemical fertilizer as a control(NF), milk vetch as green manure without chemical fertilizer(GM), winter fallow and chemical fertilizer(CF), and a combination of chemical fertilizer and milk vetch(GMCF).Significant differences were found in the responses of soil microbial communities at different sites, with sampling sites explaining 72.33%(F = 36.59,P = 0.001) of the community composition variation. The bacterial communities in the soils from Anhui, Henan, and Hubei were broadly similar, while those from Hunan were distinctly different from other locations. The analysis of Weighted UniFrac distances showed that milk vetch changed soil microbial communities compared with winter fallow. Proteobacteria and Chloroflexi predominated in these paddy soils;however, the application of green manures increased the relative abundance of Actinobacteria. There was evidence showing that the functional microbes which play important roles in the cycling of soil carbon, nitrogen(N), and sulfur(S) changed after several years of milk vetch utilization(linear discriminant analysis score > 2). The abundance of methane-oxidizing bacteria and S-reducing bacteria increased, and microbes involved in N fixation, nitrification, and denitrification also increased in some provinces. We concluded that the application of milk vetch changed the bacterial community structure and affected the functional groups related to nutrient transformation in soils at a regional scale.
文摘Background:Few studies have incorporated the evolutionary insights provided by analysis of phylogenetic structure along with community composition to assess the effects of exotic invasion on freshwater wetlands.Here,we assess the taxonomic and phylogenetic relationships among acid seep springs to investigate the potential homogenization or resistance of communities due to invasion of an exotic grass.Results:Multivariate community analyses indicated differences in community and phylogenetic composition and dispersion among acid seep springs,associated with gradients in soil moisture,canopy cover,and phylogenetic diversity.By contrast,univariate analyses showed differences in taxonomic diversity but not phylogenetic diversity among acid seep springs.Conclusions:Despite exotic invasion,individual acid seep springs remained taxonomically and phylogenetically distinct from each other.Taxonomic and phylogenetic diversity metrics revealed different aspects of composition,reinforcing the importance of including both in analyses of plant communities for understanding community assembly following exotic invasion and for management purposes.Within acid seep springs,taxonomic and phylogenetic composition appear to be driven more through environmental filtering by light and moisture than by the competitive effects following invasion of an exotic grass in support of Elton’s biotic resistance hypothesis.
