Limits...
Profile Changes in the Soil Microbial Community When Desert Becomes Oasis.

Li CH, Tang LS, Jia ZJ, Li Y - PLoS ONE (2015)

Bottom Line: To assess the effects of cultivation, the following treatments were compared with the virgin desert: CK (no fertilizer), PK, NK, NP, NPK, NPKR, and NPKM (R: straw residue; M: manure fertilizer).The proportions of extremophilic and photosynthetic groups (e.g., Deinococcus-Thermus and Cyanobacteria) decreased, while the proportions of R-strategy (e.g., Gammaproteobacteria including Xanthomonadales), nitrifying (e.g., Nitrospirae), and anaerobic bacteria (e.g., Anaerolineae) increased throughout the oasis profile.Furthermore, difference in fertilization and crop growth altered the organic carbon contents in the soil, which resulted in differences of microbial communities within oasis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China.

ABSTRACT
The conversion of virgin desert into oasis farmland creates two contrasting types of land-cover. During oasis formation with irrigation and fertilizer application, however, the changes in the soil microbial population, which play critical roles in the ecosystem, remain poorly understood. We applied high-throughput pyrosequencing to investigate bacterial and archaeal communities throughout the profile (0-3 m) in an experimental field, where irrigation and fertilization began in 1990 and cropped with winter wheat since then. To assess the effects of cultivation, the following treatments were compared with the virgin desert: CK (no fertilizer), PK, NK, NP, NPK, NPKR, and NPKM (R: straw residue; M: manure fertilizer). Irrigation had a greater impact on the overall microbial community than fertilizer application. The greatest impact occurred in topsoil (0-0.2 m), e.g., Cyanobacteria (25% total abundance) were most abundant in desert soil, while Actinobacteria (26%) were most abundant in oasis soil. The proportions of extremophilic and photosynthetic groups (e.g., Deinococcus-Thermus and Cyanobacteria) decreased, while the proportions of R-strategy (e.g., Gammaproteobacteria including Xanthomonadales), nitrifying (e.g., Nitrospirae), and anaerobic bacteria (e.g., Anaerolineae) increased throughout the oasis profile. Archaea occurred only in oasis soil. The impact of fertilizer application was mainly reflected in the non-dominant communities or finer taxonomic divisions. Oasis formation led to a dramatic shift in microbial community and enhanced soil enzyme activities. The rapidly increased soil moisture and decreased salt caused by irrigation were responsible for this shift. Furthermore, difference in fertilization and crop growth altered the organic carbon contents in the soil, which resulted in differences of microbial communities within oasis.

No MeSH data available.


Relative abundances of selected archaea and bacterial taxa in topsoil (0–0.2 m) from desert and oasis with different fertilizer treatments.Desert: the original soil from which the oasis was derived. Different letters at the top of each column indicate that treatment means are significantly different at p <0.05.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4591283&req=5

pone.0139626.g002: Relative abundances of selected archaea and bacterial taxa in topsoil (0–0.2 m) from desert and oasis with different fertilizer treatments.Desert: the original soil from which the oasis was derived. Different letters at the top of each column indicate that treatment means are significantly different at p <0.05.

Mentions: Irrigation had a significant impact on the soil microbial community in topsoil (0–0.2 m). In the desert topsoil, the most abundant phyla were Cyanobacteria (25%) and Proteobacteria (22%); whereas in the oasis, the most abundant phyla were Actinobacteria (26%) and Proteobacteria (24%) (Fig 1). The desert soil had a higher relative abundance of Cyanobacteria, Deinococcus-Thermus, Firmicutes, Bacteroidetes (Fig 1), and Alphaproteobacteria (α-proteobacteria) (Fig 2); while in the oasis soil, for all treatments there were higher relative abundances of Actinobacteria, Acidobacteria, Chloroflexi (Fig 1), Gammaproteobacteria (γ-proteobacteria), Betaproteobacteria (β-proteobacteria), Deltaproteobacteria (δ-proteobacteria), Gemmatimonadetes, and Nitrospirae (Fig 2). Moreover, archaea (including Crenarchaeota) were only found in oasis soils (Fig 2). Changes were also observed at finer taxonomic divisions (Table 2). Within the α-proteobacteria, the proportions of Rhizobiales, Sphingomonadales, Rhodobaterales were lower, but the Rhodospirillales were higher in all treatments of the oasis soil, compared to the desert soil. Within the Actinobacteria, the relative abundances of the subclasses Acidimicrobidae and Actinobacteridae were higher, but the Rubrobacteridae were lower in the oasis soils than the desert soils. In addition, all of the treatments in the oasis also resulted in higher proportions of the Xanthomonadales within the γ-phaproteobacteria, Anaerolineae within the Chloroflexi, Clostridiales within the Firmicutes and Gp 6 within the Acidobacteria, and lower proportions of the Bacillales within the Firmicutes than in the desert soil (Table 2).


Profile Changes in the Soil Microbial Community When Desert Becomes Oasis.

Li CH, Tang LS, Jia ZJ, Li Y - PLoS ONE (2015)

Relative abundances of selected archaea and bacterial taxa in topsoil (0–0.2 m) from desert and oasis with different fertilizer treatments.Desert: the original soil from which the oasis was derived. Different letters at the top of each column indicate that treatment means are significantly different at p <0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591283&req=5

pone.0139626.g002: Relative abundances of selected archaea and bacterial taxa in topsoil (0–0.2 m) from desert and oasis with different fertilizer treatments.Desert: the original soil from which the oasis was derived. Different letters at the top of each column indicate that treatment means are significantly different at p <0.05.
Mentions: Irrigation had a significant impact on the soil microbial community in topsoil (0–0.2 m). In the desert topsoil, the most abundant phyla were Cyanobacteria (25%) and Proteobacteria (22%); whereas in the oasis, the most abundant phyla were Actinobacteria (26%) and Proteobacteria (24%) (Fig 1). The desert soil had a higher relative abundance of Cyanobacteria, Deinococcus-Thermus, Firmicutes, Bacteroidetes (Fig 1), and Alphaproteobacteria (α-proteobacteria) (Fig 2); while in the oasis soil, for all treatments there were higher relative abundances of Actinobacteria, Acidobacteria, Chloroflexi (Fig 1), Gammaproteobacteria (γ-proteobacteria), Betaproteobacteria (β-proteobacteria), Deltaproteobacteria (δ-proteobacteria), Gemmatimonadetes, and Nitrospirae (Fig 2). Moreover, archaea (including Crenarchaeota) were only found in oasis soils (Fig 2). Changes were also observed at finer taxonomic divisions (Table 2). Within the α-proteobacteria, the proportions of Rhizobiales, Sphingomonadales, Rhodobaterales were lower, but the Rhodospirillales were higher in all treatments of the oasis soil, compared to the desert soil. Within the Actinobacteria, the relative abundances of the subclasses Acidimicrobidae and Actinobacteridae were higher, but the Rubrobacteridae were lower in the oasis soils than the desert soils. In addition, all of the treatments in the oasis also resulted in higher proportions of the Xanthomonadales within the γ-phaproteobacteria, Anaerolineae within the Chloroflexi, Clostridiales within the Firmicutes and Gp 6 within the Acidobacteria, and lower proportions of the Bacillales within the Firmicutes than in the desert soil (Table 2).

Bottom Line: To assess the effects of cultivation, the following treatments were compared with the virgin desert: CK (no fertilizer), PK, NK, NP, NPK, NPKR, and NPKM (R: straw residue; M: manure fertilizer).The proportions of extremophilic and photosynthetic groups (e.g., Deinococcus-Thermus and Cyanobacteria) decreased, while the proportions of R-strategy (e.g., Gammaproteobacteria including Xanthomonadales), nitrifying (e.g., Nitrospirae), and anaerobic bacteria (e.g., Anaerolineae) increased throughout the oasis profile.Furthermore, difference in fertilization and crop growth altered the organic carbon contents in the soil, which resulted in differences of microbial communities within oasis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang, China.

ABSTRACT
The conversion of virgin desert into oasis farmland creates two contrasting types of land-cover. During oasis formation with irrigation and fertilizer application, however, the changes in the soil microbial population, which play critical roles in the ecosystem, remain poorly understood. We applied high-throughput pyrosequencing to investigate bacterial and archaeal communities throughout the profile (0-3 m) in an experimental field, where irrigation and fertilization began in 1990 and cropped with winter wheat since then. To assess the effects of cultivation, the following treatments were compared with the virgin desert: CK (no fertilizer), PK, NK, NP, NPK, NPKR, and NPKM (R: straw residue; M: manure fertilizer). Irrigation had a greater impact on the overall microbial community than fertilizer application. The greatest impact occurred in topsoil (0-0.2 m), e.g., Cyanobacteria (25% total abundance) were most abundant in desert soil, while Actinobacteria (26%) were most abundant in oasis soil. The proportions of extremophilic and photosynthetic groups (e.g., Deinococcus-Thermus and Cyanobacteria) decreased, while the proportions of R-strategy (e.g., Gammaproteobacteria including Xanthomonadales), nitrifying (e.g., Nitrospirae), and anaerobic bacteria (e.g., Anaerolineae) increased throughout the oasis profile. Archaea occurred only in oasis soil. The impact of fertilizer application was mainly reflected in the non-dominant communities or finer taxonomic divisions. Oasis formation led to a dramatic shift in microbial community and enhanced soil enzyme activities. The rapidly increased soil moisture and decreased salt caused by irrigation were responsible for this shift. Furthermore, difference in fertilization and crop growth altered the organic carbon contents in the soil, which resulted in differences of microbial communities within oasis.

No MeSH data available.